Discussion:
Bicentennial GOES satellite clock
(too old to reply)
Tim Shoppa
2018-08-09 02:29:24 UTC
Permalink
See the groovy picture at
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4847573/figure/f9-j110-2lom/

If anyone knows the whereabouts or history of the bicentennial GOES time
clock display, please let me know!

Tim N3QE
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Tom Van Baak
2018-08-10 14:18:52 UTC
Permalink
Tim,

Thanks for posting that photo. That space age 1976 GOES clock caught our eyes when the paper came out in 2005 (see also pages 11, 12, 13):

https://tf.nist.gov/general/pdf/2013.pdf

There was quite a bit of traffic on time-nuts around 2005 when the GOES satellite time service was turned off (and back on, and off, and on, and finally off for good). That left many of us with piles of 468 MHz GOES receivers, antennae, clocks and led to efforts to re-create the RF signals in-home so that GOES clocks would still work. There was even a commercial G2G (GPS to GOES) translator.

Anyway, I asked around about that one-off bicentennial clock in the photo and neither the authors, NIST, or Smithsonian knows where it ended up. There's tons of information on the GOES satellite system and GOES clocks in the NIST T&F archives:

https://tf.nist.gov/general/publications.htm

Best to search title for GOES, or search author for Hanson. It's a fascinating glimpse into the recent past. Yes, it's sad that GOES (and Omega, and Loran-C) aren't operational anymore, but GPS does such a better job. Plus we now have cable, WiFi, cell phones, the internet, Iridium, etc.

If you wanted to build your own Bicentennial GOES Clock, the design was published, including source code -- for its i4004 (!!) CPU. If you have even one minute to spare, see attached image and click on these two PDF's:

"Satellite Controlled Digital Clock System (patent)"
https://tf.nist.gov/general/pdf/1791.pdf

"A Satellite-Controlled Digital Clock (NBS TN-681)"
https://tf.nist.gov/general/pdf/452.pdf

/tvb


----- Original Message -----
From: "Tim Shoppa" <***@gmail.com>
To: "Discussion of precise time and frequency measurement" <time-***@lists.febo.com>
Sent: Wednesday, August 08, 2018 7:29 PM
Subject: [time-nuts] Bicentennial GOES satellite clock


> See the groovy picture at
> https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4847573/figure/f9-j110-2lom/
>
> If anyone knows the whereabouts or history of the bicentennial GOES time
> clock display, please let me know!
>
> Tim N3QE
Tim Shoppa
2018-08-10 15:24:58 UTC
Permalink
Tom, thank you for those links!

Yes, my employer used successive generations of GOES satellite clock
receivers that generated IRIG signals piped around the company. Even though
my company started in revenue service in 1976 I don't think we had our
first GOES clock until a few years later.

The IRIG signals were not just used for internal displays. In the 1980's
each passenger station got public facing LED clocks that were standard
NatSemi LED display chips but "force synchronized" at top of each hour and
at midnight via audio tones driving relay contacts that stimulated the set
pushbutton inputs of the NatSemi chips.

When GOES was turned off in 2004, then we switched to NTP controlled IRIG
generator and only in the past month have we removed the last internal IRIG
clock displays. All the passenger facing LED clocks had been removed in the
past decade too.

I am building a miniature reproduction of the bicentennial clock although
it will obviously not be run through GOES or use a 4004. Current prototype
uses a ESP8266 and NTP over WiFi.

Tim N3QE

On Fri, Aug 10, 2018 at 10:18 AM, Tom Van Baak <***@leapsecond.com> wrote:

> Tim,
>
> Thanks for posting that photo. That space age 1976 GOES clock caught our
> eyes when the paper came out in 2005 (see also pages 11, 12, 13):
>
> https://tf.nist.gov/general/pdf/2013.pdf
>
> There was quite a bit of traffic on time-nuts around 2005 when the GOES
> satellite time service was turned off (and back on, and off, and on, and
> finally off for good). That left many of us with piles of 468 MHz GOES
> receivers, antennae, clocks and led to efforts to re-create the RF signals
> in-home so that GOES clocks would still work. There was even a commercial
> G2G (GPS to GOES) translator.
>
> Anyway, I asked around about that one-off bicentennial clock in the photo
> and neither the authors, NIST, or Smithsonian knows where it ended up.
> There's tons of information on the GOES satellite system and GOES clocks in
> the NIST T&F archives:
>
> https://tf.nist.gov/general/publications.htm
>
> Best to search title for GOES, or search author for Hanson. It's a
> fascinating glimpse into the recent past. Yes, it's sad that GOES (and
> Omega, and Loran-C) aren't operational anymore, but GPS does such a better
> job. Plus we now have cable, WiFi, cell phones, the internet, Iridium, etc.
>
> If you wanted to build your own Bicentennial GOES Clock, the design was
> published, including source code -- for its i4004 (!!) CPU. If you have
> even one minute to spare, see attached image and click on these two PDF's:
>
> "Satellite Controlled Digital Clock System (patent)"
> https://tf.nist.gov/general/pdf/1791.pdf
>
> "A Satellite-Controlled Digital Clock (NBS TN-681)"
> https://tf.nist.gov/general/pdf/452.pdf
>
> /tvb
>
>
> ----- Original Message -----
> From: "Tim Shoppa" <***@gmail.com>
> To: "Discussion of precise time and frequency measurement" <
> time-***@lists.febo.com>
> Sent: Wednesday, August 08, 2018 7:29 PM
> Subject: [time-nuts] Bicentennial GOES satellite clock
>
>
> > See the groovy picture at
> > https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4847573/
> figure/f9-j110-2lom/
> >
> > If anyone knows the whereabouts or history of the bicentennial GOES time
> > clock display, please let me know!
> >
> > Tim N3QE
>
>
> _______________________________________________
> time-nuts mailing list -- time-***@lists.febo.com
> To unsubscribe, go to http://lists.febo.com/mailman/
> listinfo/time-nuts_lists.febo.com
> and follow the instructions there.
>
>
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paul swed
2018-08-10 15:25:37 UTC
Permalink
yes I still have a modified 468 that works using some stuff I design back
in 2005. I do power the dc468 up every now and then.
Still works. Though a couple of the panaplex displays are getting a bit
cranky. But completely agree that GPS has seriously spoiled me as it drives
time code clocks.
Regards
Paul
WB8TSL

On Fri, Aug 10, 2018 at 10:18 AM, Tom Van Baak <***@leapsecond.com> wrote:

> Tim,
>
> Thanks for posting that photo. That space age 1976 GOES clock caught our
> eyes when the paper came out in 2005 (see also pages 11, 12, 13):
>
> https://tf.nist.gov/general/pdf/2013.pdf
>
> There was quite a bit of traffic on time-nuts around 2005 when the GOES
> satellite time service was turned off (and back on, and off, and on, and
> finally off for good). That left many of us with piles of 468 MHz GOES
> receivers, antennae, clocks and led to efforts to re-create the RF signals
> in-home so that GOES clocks would still work. There was even a commercial
> G2G (GPS to GOES) translator.
>
> Anyway, I asked around about that one-off bicentennial clock in the photo
> and neither the authors, NIST, or Smithsonian knows where it ended up.
> There's tons of information on the GOES satellite system and GOES clocks in
> the NIST T&F archives:
>
> https://tf.nist.gov/general/publications.htm
>
> Best to search title for GOES, or search author for Hanson. It's a
> fascinating glimpse into the recent past. Yes, it's sad that GOES (and
> Omega, and Loran-C) aren't operational anymore, but GPS does such a better
> job. Plus we now have cable, WiFi, cell phones, the internet, Iridium, etc.
>
> If you wanted to build your own Bicentennial GOES Clock, the design was
> published, including source code -- for its i4004 (!!) CPU. If you have
> even one minute to spare, see attached image and click on these two PDF's:
>
> "Satellite Controlled Digital Clock System (patent)"
> https://tf.nist.gov/general/pdf/1791.pdf
>
> "A Satellite-Controlled Digital Clock (NBS TN-681)"
> https://tf.nist.gov/general/pdf/452.pdf
>
> /tvb
>
>
> ----- Original Message -----
> From: "Tim Shoppa" <***@gmail.com>
> To: "Discussion of precise time and frequency measurement" <
> time-***@lists.febo.com>
> Sent: Wednesday, August 08, 2018 7:29 PM
> Subject: [time-nuts] Bicentennial GOES satellite clock
>
>
> > See the groovy picture at
> > https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4847573/
> figure/f9-j110-2lom/
> >
> > If anyone knows the whereabouts or history of the bicentennial GOES time
> > clock display, please let me know!
> >
> > Tim N3QE
>
>
> _______________________________________________
> time-nuts mailing list -- time-***@lists.febo.com
> To unsubscribe, go to http://lists.febo.com/mailman/
> listinfo/time-nuts_lists.febo.com
> and follow the instructions there.
>
>
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Lester Veenstra
2018-08-10 18:25:41 UTC
Permalink
Used to work with Wayne on two time transfer via satellite
Great guy


Lester B Veenstra  K1YCM MØYCM W8YCM 6Y6Y
***@veenstras.com

Physical and US Postal Addresses
5 Shrine Club Drive (Physical)
HC84 452 Stable Ln (RFD USPS Mail)
Keyser WV 26726
GPS: 39.336826 N  78.982287 W (Google)
GPS: 39.33682 N  78.9823741 W (GPSDO)


Telephones:
Home:                     +1-304-289-6057
US cell                    +1-304-790-9192
Jamaica cell:           +1-876-456-8898
 

-----Original Message-----
From: time-nuts [mailto:time-nuts-***@lists.febo.com] On Behalf Of Tom
Van Baak
Sent: Friday, August 10, 2018 10:19 AM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Bicentennial GOES satellite clock

Tim,

Thanks for posting that photo. That space age 1976 GOES clock caught our
eyes when the paper came out in 2005 (see also pages 11, 12, 13):

https://tf.nist.gov/general/pdf/2013.pdf

There was quite a bit of traffic on time-nuts around 2005 when the GOES
satellite time service was turned off (and back on, and off, and on, and
finally off for good). That left many of us with piles of 468 MHz GOES
receivers, antennae, clocks and led to efforts to re-create the RF signals
in-home so that GOES clocks would still work. There was even a commercial
G2G (GPS to GOES) translator.

Anyway, I asked around about that one-off bicentennial clock in the photo
and neither the authors, NIST, or Smithsonian knows where it ended up.
There's tons of information on the GOES satellite system and GOES clocks in
the NIST T&F archives:

https://tf.nist.gov/general/publications.htm

Best to search title for GOES, or search author for Hanson. It's a
fascinating glimpse into the recent past. Yes, it's sad that GOES (and
Omega, and Loran-C) aren't operational anymore, but GPS does such a better
job. Plus we now have cable, WiFi, cell phones, the internet, Iridium, etc.

If you wanted to build your own Bicentennial GOES Clock, the design was
published, including source code -- for its i4004 (!!) CPU. If you have even
one minute to spare, see attached image and click on these two PDF's:

"Satellite Controlled Digital Clock System (patent)"
https://tf.nist.gov/general/pdf/1791.pdf

"A Satellite-Controlled Digital Clock (NBS TN-681)"
https://tf.nist.gov/general/pdf/452.pdf

/tvb


----- Original Message -----
From: "Tim Shoppa" <***@gmail.com>
To: "Discussion of precise time and frequency measurement"
<time-***@lists.febo.com>
Sent: Wednesday, August 08, 2018 7:29 PM
Subject: [time-nuts] Bicentennial GOES satellite clock


> See the groovy picture at
> https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4847573/figure/f9-j110-2lom/
>
> If anyone knows the whereabouts or history of the bicentennial GOES time
> clock display, please let me know!
>
> Tim N3QE



_______________________________________________
time-nuts mailing list -- time-***@lists.febo.com
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
Scott McGrath
2018-08-12 14:29:41 UTC
Permalink
And with dependence on GPS we have created a serious vulnerability as too many critical pieces of infrastructure are dependent on a SINGLE precision timing and positioning system.

I can use a sextant and have a copy of Bowditch. But they only work on clear days and nights.

if GPS goes down for any reason. Whats the backup solution?


On Aug 10, 2018, at 2:25 PM, Lester Veenstra <***@veenstras.com> wrote:

Used to work with Wayne on two time transfer via satellite
Great guy


Lester B Veenstra K1YCM MØYCM W8YCM 6Y6Y
***@veenstras.com

Physical and US Postal Addresses
5 Shrine Club Drive (Physical)
HC84 452 Stable Ln (RFD USPS Mail)
Keyser WV 26726
GPS: 39.336826 N 78.982287 W (Google)
GPS: 39.33682 N 78.9823741 W (GPSDO)


Telephones:
Home: +1-304-289-6057
US cell +1-304-790-9192
Jamaica cell: +1-876-456-8898


-----Original Message-----
From: time-nuts [mailto:time-nuts-***@lists.febo.com] On Behalf Of Tom
Van Baak
Sent: Friday, August 10, 2018 10:19 AM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Bicentennial GOES satellite clock

Tim,

Thanks for posting that photo. That space age 1976 GOES clock caught our
eyes when the paper came out in 2005 (see also pages 11, 12, 13):

https://tf.nist.gov/general/pdf/2013.pdf

There was quite a bit of traffic on time-nuts around 2005 when the GOES
satellite time service was turned off (and back on, and off, and on, and
finally off for good). That left many of us with piles of 468 MHz GOES
receivers, antennae, clocks and led to efforts to re-create the RF signals
in-home so that GOES clocks would still work. There was even a commercial
G2G (GPS to GOES) translator.

Anyway, I asked around about that one-off bicentennial clock in the photo
and neither the authors, NIST, or Smithsonian knows where it ended up.
There's tons of information on the GOES satellite system and GOES clocks in
the NIST T&F archives:

https://tf.nist.gov/general/publications.htm

Best to search title for GOES, or search author for Hanson. It's a
fascinating glimpse into the recent past. Yes, it's sad that GOES (and
Omega, and Loran-C) aren't operational anymore, but GPS does such a better
job. Plus we now have cable, WiFi, cell phones, the internet, Iridium, etc.

If you wanted to build your own Bicentennial GOES Clock, the design was
published, including source code -- for its i4004 (!!) CPU. If you have even
one minute to spare, see attached image and click on these two PDF's:

"Satellite Controlled Digital Clock System (patent)"
https://tf.nist.gov/general/pdf/1791.pdf

"A Satellite-Controlled Digital Clock (NBS TN-681)"
https://tf.nist.gov/general/pdf/452.pdf

/tvb


----- Original Message -----
From: "Tim Shoppa" <***@gmail.com>
To: "Discussion of precise time and frequency measurement"
<time-***@lists.febo.com>
Sent: Wednesday, August 08, 2018 7:29 PM
Subject: [time-nuts] Bicentennial GOES satellite clock


> See the groovy picture at
> https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4847573/figure/f9-j110-2lom/
>
> If anyone knows the whereabouts or history of the bicentennial GOES time
> clock display, please let me know!
>
> Tim N3QE



_______________________________________________
time-nuts mailing list -- time-***@lists.febo.com
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

_______________________________________________
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and follow t
Bob kb8tq
2018-08-12 15:07:51 UTC
Permalink
Hi

If GPS goes down, you then have Glonass. If Glonass goes down, you have Galileo. If all of those go down and you are in the
right region, the Chinese and Japanese both have systems you could use.

In terms of *system* failure, there’s a lot of redundancy out there ….. Yes, you *would* have to own gear that works with all
those systems. You might also go with multi-band (quad band maybe) gear to eliminate various other issues.

Widely deployed electronic navigation isn’t all that old. People got along for a really long time without it ….. That includes a whole
bunch of folks who had no clue how a sextant works.

Bob

> On Aug 12, 2018, at 10:29 AM, Scott McGrath <***@gmail.com> wrote:
>
> And with dependence on GPS we have created a serious vulnerability as too many critical pieces of infrastructure are dependent on a SINGLE precision timing and positioning system.
>
> I can use a sextant and have a copy of Bowditch. But they only work on clear days and nights.
>
> if GPS goes down for any reason. Whats the backup solution?
>
>
> On Aug 10, 2018, at 2:25 PM, Lester Veenstra <***@veenstras.com> wrote:
>
> Used to work with Wayne on two time transfer via satellite
> Great guy
>
>
> Lester B Veenstra K1YCM MØYCM W8YCM 6Y6Y
> ***@veenstras.com
>
> Physical and US Postal Addresses
> 5 Shrine Club Drive (Physical)
> HC84 452 Stable Ln (RFD USPS Mail)
> Keyser WV 26726
> GPS: 39.336826 N 78.982287 W (Google)
> GPS: 39.33682 N 78.9823741 W (GPSDO)
>
>
> Telephones:
> Home: +1-304-289-6057
> US cell +1-304-790-9192
> Jamaica cell: +1-876-456-8898
>
>
> -----Original Message-----
> From: time-nuts [mailto:time-nuts-***@lists.febo.com] On Behalf Of Tom
> Van Baak
> Sent: Friday, August 10, 2018 10:19 AM
> To: Discussion of precise time and frequency measurement
> Subject: Re: [time-nuts] Bicentennial GOES satellite clock
>
> Tim,
>
> Thanks for posting that photo. That space age 1976 GOES clock caught our
> eyes when the paper came out in 2005 (see also pages 11, 12, 13):
>
> https://tf.nist.gov/general/pdf/2013.pdf
>
> There was quite a bit of traffic on time-nuts around 2005 when the GOES
> satellite time service was turned off (and back on, and off, and on, and
> finally off for good). That left many of us with piles of 468 MHz GOES
> receivers, antennae, clocks and led to efforts to re-create the RF signals
> in-home so that GOES clocks would still work. There was even a commercial
> G2G (GPS to GOES) translator.
>
> Anyway, I asked around about that one-off bicentennial clock in the photo
> and neither the authors, NIST, or Smithsonian knows where it ended up.
> There's tons of information on the GOES satellite system and GOES clocks in
> the NIST T&F archives:
>
> https://tf.nist.gov/general/publications.htm
>
> Best to search title for GOES, or search author for Hanson. It's a
> fascinating glimpse into the recent past. Yes, it's sad that GOES (and
> Omega, and Loran-C) aren't operational anymore, but GPS does such a better
> job. Plus we now have cable, WiFi, cell phones, the internet, Iridium, etc.
>
> If you wanted to build your own Bicentennial GOES Clock, the design was
> published, including source code -- for its i4004 (!!) CPU. If you have even
> one minute to spare, see attached image and click on these two PDF's:
>
> "Satellite Controlled Digital Clock System (patent)"
> https://tf.nist.gov/general/pdf/1791.pdf
>
> "A Satellite-Controlled Digital Clock (NBS TN-681)"
> https://tf.nist.gov/general/pdf/452.pdf
>
> /tvb
>
>
> ----- Original Message -----
> From: "Tim Shoppa" <***@gmail.com>
> To: "Discussion of precise time and frequency measurement"
> <time-***@lists.febo.com>
> Sent: Wednesday, August 08, 2018 7:29 PM
> Subject: [time-nuts] Bicentennial GOES satellite clock
>
>
>> See the groovy picture at
>> https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4847573/figure/f9-j110-2lom/
>>
>> If anyone knows the whereabouts or history of the bicentennial GOES time
>> clock display, please let me know!
>>
>> Tim N3QE
>
>
>
> _______________________________________________
> time-nuts mailing list -- time-***@lists.febo.com
> To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> and follow the instructions there.
>
> _______________________________________________
> time-nuts mailing list -- time-***@lists.febo.com
> To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> and follow the instructions there.


_______________________________________________
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djl
2018-08-12 19:06:55 UTC
Permalink
all you need for a once a day noon fix is a level surface, a stick, and
some pebbles.
Don

On 2018-08-12 08:29, Scott McGrath wrote:
> And with dependence on GPS we have created a serious vulnerability as
> too many critical pieces of infrastructure are dependent on a SINGLE
> precision timing and positioning system.
>
> I can use a sextant and have a copy of Bowditch. But they only work
> on clear days and nights.
>
> if GPS goes down for any reason. Whats the backup solution?
>
>
> On Aug 10, 2018, at 2:25 PM, Lester Veenstra <***@veenstras.com>
> wrote:
>
> Used to work with Wayne on two time transfer via satellite
> Great guy
>
>
> Lester B Veenstra K1YCM MØYCM W8YCM 6Y6Y
> ***@veenstras.com
>
> Physical and US Postal Addresses
> 5 Shrine Club Drive (Physical)
> HC84 452 Stable Ln (RFD USPS Mail)
> Keyser WV 26726
> GPS: 39.336826 N 78.982287 W (Google)
> GPS: 39.33682 N 78.9823741 W (GPSDO)
>
>
> Telephones:
> Home: +1-304-289-6057
> US cell +1-304-790-9192
> Jamaica cell: +1-876-456-8898
>
>
> -----Original Message-----
> From: time-nuts [mailto:time-nuts-***@lists.febo.com] On Behalf Of
> Tom
> Van Baak
> Sent: Friday, August 10, 2018 10:19 AM
> To: Discussion of precise time and frequency measurement
> Subject: Re: [time-nuts] Bicentennial GOES satellite clock
>
> Tim,
>
> Thanks for posting that photo. That space age 1976 GOES clock caught
> our
> eyes when the paper came out in 2005 (see also pages 11, 12, 13):
>
> https://tf.nist.gov/general/pdf/2013.pdf
>
> There was quite a bit of traffic on time-nuts around 2005 when the GOES
> satellite time service was turned off (and back on, and off, and on,
> and
> finally off for good). That left many of us with piles of 468 MHz GOES
> receivers, antennae, clocks and led to efforts to re-create the RF
> signals
> in-home so that GOES clocks would still work. There was even a
> commercial
> G2G (GPS to GOES) translator.
>
> Anyway, I asked around about that one-off bicentennial clock in the
> photo
> and neither the authors, NIST, or Smithsonian knows where it ended up.
> There's tons of information on the GOES satellite system and GOES
> clocks in
> the NIST T&F archives:
>
> https://tf.nist.gov/general/publications.htm
>
> Best to search title for GOES, or search author for Hanson. It's a
> fascinating glimpse into the recent past. Yes, it's sad that GOES (and
> Omega, and Loran-C) aren't operational anymore, but GPS does such a
> better
> job. Plus we now have cable, WiFi, cell phones, the internet, Iridium,
> etc.
>
> If you wanted to build your own Bicentennial GOES Clock, the design was
> published, including source code -- for its i4004 (!!) CPU. If you have
> even
> one minute to spare, see attached image and click on these two PDF's:
>
> "Satellite Controlled Digital Clock System (patent)"
> https://tf.nist.gov/general/pdf/1791.pdf
>
> "A Satellite-Controlled Digital Clock (NBS TN-681)"
> https://tf.nist.gov/general/pdf/452.pdf
>
> /tvb
>
>
> ----- Original Message -----
> From: "Tim Shoppa" <***@gmail.com>
> To: "Discussion of precise time and frequency measurement"
> <time-***@lists.febo.com>
> Sent: Wednesday, August 08, 2018 7:29 PM
> Subject: [time-nuts] Bicentennial GOES satellite clock
>
>
>> See the groovy picture at
>> https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4847573/figure/f9-j110-2lom/
>>
>> If anyone knows the whereabouts or history of the bicentennial GOES
>> time
>> clock display, please let me know!
>>
>> Tim N3QE
>
>
>
> _______________________________________________
> time-nuts mailing list -- time-***@lists.febo.com
> To unsubscribe, go to
> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> and follow the instructions there.
>
> _______________________________________________
> time-nuts mailing list -- time-***@lists.febo.com
> To unsubscribe, go to
> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> and follow the instructions there.

--
Dr. Don Latham
PO Box 404, Frenchtown, MT, 59834
VOX: 406-626-4304


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Dana Whitlow
2018-08-12 23:29:39 UTC
Permalink
How exactly does one get submillisecond time of day precision with a
sextant?
(even if sticks and pebbles are thrown into the mix)
I'd say more like ~1 sec precision on a really fine day, it the sextant is
wielded by
a skilled and practiced operator who has apriori knowledge of his location.

And what about standard frequency dissemination?

I'm also upset about the notion of time distribution and transfer by
internet. Now
there's a fine example of a system that could be brought down by a single
competent
hacker!

And all it takes is one really good solar flare to bring down GPS (and
Glonass and
the others) semipermanently, if the reports I read are true.

I argue that instead of shutting down distribution avenues, NIST should be
making
additional ones available.

A lot has been said lately about how rapidly our technology is exploding.
But think
about how much of that is critically dependent on precision time transfer
over the
planet, and how much longer it would take mankind to recover from (insert
your favorite
disaster here) without good time and frequency transfer still up and
working.

Dana





On Sun, Aug 12, 2018 at 2:06 PM, djl <***@montana.com> wrote:

> all you need for a once a day noon fix is a level surface, a stick, and
> some pebbles.
> Don
>
>
> On 2018-08-12 08:29, Scott McGrath wrote:
>
>> And with dependence on GPS we have created a serious vulnerability as
>> too many critical pieces of infrastructure are dependent on a SINGLE
>> precision timing and positioning system.
>>
>> I can use a sextant and have a copy of Bowditch. But they only work
>> on clear days and nights.
>>
>> if GPS goes down for any reason. Whats the backup solution?
>>
>>
>> On Aug 10, 2018, at 2:25 PM, Lester Veenstra <***@veenstras.com> wrote:
>>
>> Used to work with Wayne on two time transfer via satellite
>> Great guy
>>
>>
>> Lester B Veenstra K1YCM MØYCM W8YCM 6Y6Y
>> ***@veenstras.com
>>
>> Physical and US Postal Addresses
>> 5 Shrine Club Drive (Physical)
>> HC84 452 Stable Ln (RFD USPS Mail)
>> Keyser WV 26726
>> GPS: 39.336826 N 78.982287 W (Google)
>> GPS: 39.33682 N 78.9823741 W (GPSDO)
>>
>>
>> Telephones:
>> Home: +1-304-289-6057
>> US cell +1-304-790-9192
>> Jamaica cell: +1-876-456-8898
>>
>>
>> -----Original Message-----
>> From: time-nuts [mailto:time-nuts-***@lists.febo.com] On Behalf Of
>> Tom
>> Van Baak
>> Sent: Friday, August 10, 2018 10:19 AM
>> To: Discussion of precise time and frequency measurement
>> Subject: Re: [time-nuts] Bicentennial GOES satellite clock
>>
>> Tim,
>>
>> Thanks for posting that photo. That space age 1976 GOES clock caught our
>> eyes when the paper came out in 2005 (see also pages 11, 12, 13):
>>
>> https://tf.nist.gov/general/pdf/2013.pdf
>>
>> There was quite a bit of traffic on time-nuts around 2005 when the GOES
>> satellite time service was turned off (and back on, and off, and on, and
>> finally off for good). That left many of us with piles of 468 MHz GOES
>> receivers, antennae, clocks and led to efforts to re-create the RF signals
>> in-home so that GOES clocks would still work. There was even a commercial
>> G2G (GPS to GOES) translator.
>>
>> Anyway, I asked around about that one-off bicentennial clock in the photo
>> and neither the authors, NIST, or Smithsonian knows where it ended up.
>> There's tons of information on the GOES satellite system and GOES clocks
>> in
>> the NIST T&F archives:
>>
>> https://tf.nist.gov/general/publications.htm
>>
>> Best to search title for GOES, or search author for Hanson. It's a
>> fascinating glimpse into the recent past. Yes, it's sad that GOES (and
>> Omega, and Loran-C) aren't operational anymore, but GPS does such a better
>> job. Plus we now have cable, WiFi, cell phones, the internet, Iridium,
>> etc.
>>
>> If you wanted to build your own Bicentennial GOES Clock, the design was
>> published, including source code -- for its i4004 (!!) CPU. If you have
>> even
>> one minute to spare, see attached image and click on these two PDF's:
>>
>> "Satellite Controlled Digital Clock System (patent)"
>> https://tf.nist.gov/general/pdf/1791.pdf
>>
>> "A Satellite-Controlled Digital Clock (NBS TN-681)"
>> https://tf.nist.gov/general/pdf/452.pdf
>>
>> /tvb
>>
>>
>> ----- Original Message -----
>> From: "Tim Shoppa" <***@gmail.com>
>> To: "Discussion of precise time and frequency measurement"
>> <time-***@lists.febo.com>
>> Sent: Wednesday, August 08, 2018 7:29 PM
>> Subject: [time-nuts] Bicentennial GOES satellite clock
>>
>>
>> See the groovy picture at
>>> https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4847573/figure/
>>> f9-j110-2lom/
>>>
>>> If anyone knows the whereabouts or history of the bicentennial GOES time
>>> clock display, please let me know!
>>>
>>> Tim N3QE
>>>
>>
>>
>>
>> _______________________________________________
>> time-nuts mailing list -- time-***@lists.febo.com
>> To unsubscribe, go to
>> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
>> and follow the instructions there.
>>
>> _______________________________________________
>> time-nuts mailing list -- time-***@lists.febo.com
>> To unsubscribe, go to
>> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
>> and follow the instructions there.
>>
>
> --
> Dr. Don Latham
> PO Box 404, Frenchtown, MT, 59834
> VOX: 406-626-4304
>
>
>
> _______________________________________________
> time-nuts mailing list -- time-***@lists.febo.com
> To unsubscribe, go to http://lists.febo.com/mailman/
> listinfo/time-nuts_lists.febo.com
> and follow the instructions there.
>
_______________________________________________
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and fol
Bob kb8tq
2018-08-12 23:48:52 UTC
Permalink
Hi

Well…. there’s also the solar flare that vaporizes the planet earth :)

A flare big enough to take out all the sat systems would disrupt a lot more than just navigation.
It also probably is big enough to take out HF radio gear as well. It takes a *lot* of energy to
permanently take out a sat system. Hour or two disruptions … sure … total destruction, that’s
getting into crazy levels.

Bob

> On Aug 12, 2018, at 7:29 PM, Dana Whitlow <***@gmail.com> wrote:
>
> How exactly does one get submillisecond time of day precision with a
> sextant?
> (even if sticks and pebbles are thrown into the mix)
> I'd say more like ~1 sec precision on a really fine day, it the sextant is
> wielded by
> a skilled and practiced operator who has apriori knowledge of his location.
>
> And what about standard frequency dissemination?
>
> I'm also upset about the notion of time distribution and transfer by
> internet. Now
> there's a fine example of a system that could be brought down by a single
> competent
> hacker!
>
> And all it takes is one really good solar flare to bring down GPS (and
> Glonass and
> the others) semipermanently, if the reports I read are true.
>
> I argue that instead of shutting down distribution avenues, NIST should be
> making
> additional ones available.
>
> A lot has been said lately about how rapidly our technology is exploding.
> But think
> about how much of that is critically dependent on precision time transfer
> over the
> planet, and how much longer it would take mankind to recover from (insert
> your favorite
> disaster here) without good time and frequency transfer still up and
> working.
>
> Dana
>
>
>
>
>
> On Sun, Aug 12, 2018 at 2:06 PM, djl <***@montana.com> wrote:
>
>> all you need for a once a day noon fix is a level surface, a stick, and
>> some pebbles.
>> Don
>>
>>
>> On 2018-08-12 08:29, Scott McGrath wrote:
>>
>>> And with dependence on GPS we have created a serious vulnerability as
>>> too many critical pieces of infrastructure are dependent on a SINGLE
>>> precision timing and positioning system.
>>>
>>> I can use a sextant and have a copy of Bowditch. But they only work
>>> on clear days and nights.
>>>
>>> if GPS goes down for any reason. Whats the backup solution?
>>>
>>>
>>> On Aug 10, 2018, at 2:25 PM, Lester Veenstra <***@veenstras.com> wrote:
>>>
>>> Used to work with Wayne on two time transfer via satellite
>>> Great guy
>>>
>>>
>>> Lester B Veenstra K1YCM MØYCM W8YCM 6Y6Y
>>> ***@veenstras.com
>>>
>>> Physical and US Postal Addresses
>>> 5 Shrine Club Drive (Physical)
>>> HC84 452 Stable Ln (RFD USPS Mail)
>>> Keyser WV 26726
>>> GPS: 39.336826 N 78.982287 W (Google)
>>> GPS: 39.33682 N 78.9823741 W (GPSDO)
>>>
>>>
>>> Telephones:
>>> Home: +1-304-289-6057
>>> US cell +1-304-790-9192
>>> Jamaica cell: +1-876-456-8898
>>>
>>>
>>> -----Original Message-----
>>> From: time-nuts [mailto:time-nuts-***@lists.febo.com] On Behalf Of
>>> Tom
>>> Van Baak
>>> Sent: Friday, August 10, 2018 10:19 AM
>>> To: Discussion of precise time and frequency measurement
>>> Subject: Re: [time-nuts] Bicentennial GOES satellite clock
>>>
>>> Tim,
>>>
>>> Thanks for posting that photo. That space age 1976 GOES clock caught our
>>> eyes when the paper came out in 2005 (see also pages 11, 12, 13):
>>>
>>> https://tf.nist.gov/general/pdf/2013.pdf
>>>
>>> There was quite a bit of traffic on time-nuts around 2005 when the GOES
>>> satellite time service was turned off (and back on, and off, and on, and
>>> finally off for good). That left many of us with piles of 468 MHz GOES
>>> receivers, antennae, clocks and led to efforts to re-create the RF signals
>>> in-home so that GOES clocks would still work. There was even a commercial
>>> G2G (GPS to GOES) translator.
>>>
>>> Anyway, I asked around about that one-off bicentennial clock in the photo
>>> and neither the authors, NIST, or Smithsonian knows where it ended up.
>>> There's tons of information on the GOES satellite system and GOES clocks
>>> in
>>> the NIST T&F archives:
>>>
>>> https://tf.nist.gov/general/publications.htm
>>>
>>> Best to search title for GOES, or search author for Hanson. It's a
>>> fascinating glimpse into the recent past. Yes, it's sad that GOES (and
>>> Omega, and Loran-C) aren't operational anymore, but GPS does such a better
>>> job. Plus we now have cable, WiFi, cell phones, the internet, Iridium,
>>> etc.
>>>
>>> If you wanted to build your own Bicentennial GOES Clock, the design was
>>> published, including source code -- for its i4004 (!!) CPU. If you have
>>> even
>>> one minute to spare, see attached image and click on these two PDF's:
>>>
>>> "Satellite Controlled Digital Clock System (patent)"
>>> https://tf.nist.gov/general/pdf/1791.pdf
>>>
>>> "A Satellite-Controlled Digital Clock (NBS TN-681)"
>>> https://tf.nist.gov/general/pdf/452.pdf
>>>
>>> /tvb
>>>
>>>
>>> ----- Original Message -----
>>> From: "Tim Shoppa" <***@gmail.com>
>>> To: "Discussion of precise time and frequency measurement"
>>> <time-***@lists.febo.com>
>>> Sent: Wednesday, August 08, 2018 7:29 PM
>>> Subject: [time-nuts] Bicentennial GOES satellite clock
>>>
>>>
>>> See the groovy picture at
>>>> https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4847573/figure/
>>>> f9-j110-2lom/
>>>>
>>>> If anyone knows the whereabouts or history of the bicentennial GOES time
>>>> clock display, please let me know!
>>>>
>>>> Tim N3QE
>>>>
>>>
>>>
>>>
>>> _______________________________________________
>>> time-nuts mailing list -- time-***@lists.febo.com
>>> To unsubscribe, go to
>>> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
>>> and follow the instructions there.
>>>
>>> _______________________________________________
>>> time-nuts mailing list -- time-***@lists.febo.com
>>> To unsubscribe, go to
>>> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
>>> and follow the instructions there.
>>>
>>
>> --
>> Dr. Don Latham
>> PO Box 404, Frenchtown, MT, 59834
>> VOX: 406-626-4304
>>
>>
>>
>> _______________________________________________
>> time-nuts mailing list -- time-***@lists.febo.com
>> To unsubscribe, go to http://lists.febo.com/mailman/
>> listinfo/time-nuts_lists.febo.com
>> and follow the instructions there.
>>
> _______________________________________________
> time-nuts mailing list -- time-***@lists.febo.com
> To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> and follow the instructions there.


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David I. Emery
2018-08-13 01:36:12 UTC
Permalink
On Sun, Aug 12, 2018 at 07:48:52PM -0400, Bob kb8tq wrote:
> Hi
>
> Well???. there???s also the solar flare that vaporizes the planet earth :)
>
> A flare big enough to take out all the sat systems would disrupt a lot more than just navigation.
> It also probably is big enough to take out HF radio gear as well. It takes a *lot* of energy to
> permanently take out a sat system. Hour or two disruptions ??? sure ??? total destruction, that???s
> getting into crazy levels.

Not so clear, big events can cause satellites to fail due to
large charges and voltages on induced on surfaces of the bird that cause
arcs - and also bombardment by energetic particles that can cause logic
states in chips to get tweaked (SEDs) and crash the control electronics
and CPUS and/or confuse vital sensors.. causing the bird to enter modes
that may not be safe for it or recoverable - more than a few satellites
have died of these kinds of things.

Whether ENOUGH GPS/Galileo/Glonnass/Baideu birds would fail to
eliminate them as a functioning constellation is probably somewhat
unlikely... however.

But It is much more likely that orbits would be less accurately
known for a while due to atmospheric heating and increased drag and
maybe also due to disturbances in satellite orientation and power and
thermal status during the event that could both change drag and perhaps
even induce slight impulses if gas jets or similar means were required
to recover the bird and make it stable again. And the power and
thermal perturbations in emergency mode shutdown configurations might
well impact the on board clock performance and accuracy (even maybe just
from the extra radiation as the magnetopause moved inside the satellite
orbits in an extreme event).

So in addition to the disturbed propagation through the
ionosphere causing degraded performance there well could be significant
errors in ephemerides (basic bird position) that would do so too for a
while.

And recovering a whole constellation of confused, sick and
dangerously misconfigured satellites during a massive world wide event
might be less easy than one might first imagine as the resources
required on the ground would probably be damaged and disabled by other
effects (massive nation wide power grid collapses and the like) and
would certainly be stretched thin by all the urgent problems to get
under control before individual satellites started to become nearly or
completely unrecoverable.

And there are certainly positive feedback vicious spiral effects
here - such as lack of time and position accuracy caused secondary
problems such as sync failures in fiber rings and the like that might
take out parts of the Internet and cell systems) and make it much harder
to recover the satellites due to lack of effective communications on the
ground.

I'd expect that decently designed HF and LF radio time and
positioning systems would be VERY much more resistant to lethal damage
by flare EMPs... hard to see how massive earth magnetic events could
kill LF or HF receivers that were even modestly hardened against EMP
simply because otherwise local lightning would be frying them regularly.

And the HF and LF transmitters involved should be pretty self
protecting too... maybe their power supply would be the weak point as
the grid collapsed but this is a problem that can be cheaply handled
with well known and proved diesel generator technology.



--
Dave Emery N1PRE/AE, ***@dieconsulting.com DIE Consulting, Weston, Mass 02493
"An empty zombie mind with a forlorn barely readable weatherbeaten
'For Rent' sign still vainly flapping outside on the weed encrusted pole - in
celebration of what could have been, but wasn't and is not to be now either."


_______________________________________________
time-nuts mailing list -- time-***@lists.febo.com
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
Bryan _
2018-08-13 05:49:50 UTC
Permalink
There have been a few television documentaries over the years on the Carrington event of 1859.


https://www.history.com/news/a-perfect-solar-superstorm-the-1859-carrington-event




-=Bryan=-


________________________________
From: time-nuts <time-nuts-***@lists.febo.com> on behalf of David I. Emery <***@dieconsulting.com>
Sent: August 12, 2018 6:36 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Bicentennial GOES satellite clock

On Sun, Aug 12, 2018 at 07:48:52PM -0400, Bob kb8tq wrote:
> Hi
>
> Well???. there???s also the solar flare that vaporizes the planet earth :)
>
> A flare big enough to take out all the sat systems would disrupt a lot more than just navigation.
> It also probably is big enough to take out HF radio gear as well. It takes a *lot* of energy to
> permanently take out a sat system. Hour or two disruptions ??? sure ??? total destruction, that???s
> getting into crazy levels.

Not so clear, big events can cause satellites to fail due to
large charges and voltages on induced on surfaces of the bird that cause
arcs - and also bombardment by energetic particles that can cause logic
states in chips to get tweaked (SEDs) and crash the control electronics
and CPUS and/or confuse vital sensors.. causing the bird to enter modes
that may not be safe for it or recoverable - more than a few satellites
have died of these kinds of things.

Whether ENOUGH GPS/Galileo/Glonnass/Baideu birds would fail to
eliminate them as a functioning constellation is probably somewhat
unlikely... however.

But It is much more likely that orbits would be less accurately
known for a while due to atmospheric heating and increased drag and
maybe also due to disturbances in satellite orientation and power and
thermal status during the event that could both change drag and perhaps
even induce slight impulses if gas jets or similar means were required
to recover the bird and make it stable again. And the power and
thermal perturbations in emergency mode shutdown configurations might
well impact the on board clock performance and accuracy (even maybe just
from the extra radiation as the magnetopause moved inside the satellite
orbits in an extreme event).

So in addition to the disturbed propagation through the
ionosphere causing degraded performance there well could be significant
errors in ephemerides (basic bird position) that would do so too for a
while.

And recovering a whole constellation of confused, sick and
dangerously misconfigured satellites during a massive world wide event
might be less easy than one might first imagine as the resources
required on the ground would probably be damaged and disabled by other
effects (massive nation wide power grid collapses and the like) and
would certainly be stretched thin by all the urgent problems to get
under control before individual satellites started to become nearly or
completely unrecoverable.

And there are certainly positive feedback vicious spiral effects
here - such as lack of time and position accuracy caused secondary
problems such as sync failures in fiber rings and the like that might
take out parts of the Internet and cell systems) and make it much harder
to recover the satellites due to lack of effective communications on the
ground.

I'd expect that decently designed HF and LF radio time and
positioning systems would be VERY much more resistant to lethal damage
by flare EMPs... hard to see how massive earth magnetic events could
kill LF or HF receivers that were even modestly hardened against EMP
simply because otherwise local lightning would be frying them regularly.

And the HF and LF transmitters involved should be pretty self
protecting too... maybe their power supply would be the weak point as
the grid collapsed but this is a problem that can be cheaply handled
with well known and proved diesel generator technology.



--
Dave Emery N1PRE/AE, ***@dieconsulting.com DIE Consulting, Weston, Mass 02493
"An empty zombie mind with a forlorn barely readable weatherbeaten
'For Rent' sign still vainly flapping outside on the weed encrusted pole - in
celebration of what could have been, but wasn't and is not to be now either."


_______________________________________________
time-nuts mailing list -- time-***@lists.febo.com
To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
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and follow the instructions there.
jimlux
2018-08-13 13:07:24 UTC
Permalink
On 8/12/18 6:36 PM, David I. Emery wrote:
> On Sun, Aug 12, 2018 at 07:48:52PM -0400, Bob kb8tq wrote:
>> Hi
>>
>> Well???. there???s also the solar flare that vaporizes the planet earth :)
>>
>> A flare big enough to take out all the sat systems would disrupt a lot more than just navigation.

>
> But It is much more likely that orbits would be less accurately
> known for a while due to atmospheric heating and increased drag and
> maybe also due to disturbances in satellite orientation and power and
> thermal status during the event that could both change drag and perhaps
> even induce slight impulses if gas jets or similar means were required
> to recover the bird and make it stable again. And the power and
> thermal perturbations in emergency mode shutdown configurations might
> well impact the on board clock performance and accuracy (even maybe just
> from the extra radiation as the magnetopause moved inside the satellite
> orbits in an extreme event).

GPS is up high enough that aerodrag isn't really a problem - if you're
above 1500km, it's negligible, and they're up at 20,000km.
Solar wind pressure will push them around a bit, but not much. I would
think that if you did nothing, they'll be there for a very, very long time.

Their orbit is actually a quite high radiation zone (traversing the
radiation belts as they pass through the polar region), compared to GEO.

So the GPS satellites are pretty robust to this kind of thing.





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Andy Backus
2018-08-12 23:55:59 UTC
Permalink
A good sextant with a good operator can measure apparent altitude to 0.1 minutes of arc. The fastest apparent motion of objects in the sky due to rotation of the earth is 0.25 minutes of arc per second. So the best a sextant can do with time (assuming accurate astronomical tables and an exact knowledge of position) is 0.4 seconds of time.


acb


________________________________
From: time-nuts <time-nuts-***@lists.febo.com> on behalf of Dana Whitlow <***@gmail.com>
Sent: Sunday, August 12, 2018 4:29 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Bicentennial GOES satellite clock

How exactly does one get submillisecond time of day precision with a
sextant?
(even if sticks and pebbles are thrown into the mix)
I'd say more like ~1 sec precision on a really fine day, it the sextant is
wielded by
a skilled and practiced operator who has apriori knowledge of his location.

And what about standard frequency dissemination?

I'm also upset about the notion of time distribution and transfer by
internet. Now
there's a fine example of a system that could be brought down by a single
competent
hacker!

And all it takes is one really good solar flare to bring down GPS (and
Glonass and
the others) semipermanently, if the reports I read are true.

I argue that instead of shutting down distribution avenues, NIST should be
making
additional ones available.

A lot has been said lately about how rapidly our technology is exploding.
But think
about how much of that is critically dependent on precision time transfer
over the
planet, and how much longer it would take mankind to recover from (insert
your favorite
disaster here) without good time and frequency transfer still up and
working.

Dana





On Sun, Aug 12, 2018 at 2:06 PM, djl <***@montana.com> wrote:

> all you need for a once a day noon fix is a level surface, a stick, and
> some pebbles.
> Don
>
>
> On 2018-08-12 08:29, Scott McGrath wrote:
>
>> And with dependence on GPS we have created a serious vulnerability as
>> too many critical pieces of infrastructure are dependent on a SINGLE
>> precision timing and positioning system.
>>
>> I can use a sextant and have a copy of Bowditch. But they only work
>> on clear days and nights.
>>
>> if GPS goes down for any reason. Whats the backup solution?
>>
>>
>> On Aug 10, 2018, at 2:25 PM, Lester Veenstra <***@veenstras.com> wrote:
>>
>> Used to work with Wayne on two time transfer via satellite
>> Great guy
>>
>>
>> Lester B Veenstra K1YCM MØYCM W8YCM 6Y6Y
>> ***@veenstras.com
>>
>> Physical and US Postal Addresses
>> 5 Shrine Club Drive (Physical)
>> HC84 452 Stable Ln (RFD USPS Mail)
>> Keyser WV 26726
>> GPS: 39.336826 N 78.982287 W (Google)
>> GPS: 39.33682 N 78.9823741 W (GPSDO)
>>
>>
>> Telephones:
>> Home: +1-304-289-6057
>> US cell +1-304-790-9192
>> Jamaica cell: +1-876-456-8898
>>
>>
>> -----Original Message-----
>> From: time-nuts [mailto:time-nuts-***@lists.febo.com] On Behalf Of
>> Tom
>> Van Baak
>> Sent: Friday, August 10, 2018 10:19 AM
>> To: Discussion of precise time and frequency measurement
>> Subject: Re: [time-nuts] Bicentennial GOES satellite clock
>>
>> Tim,
>>
>> Thanks for posting that photo. That space age 1976 GOES clock caught our
>> eyes when the paper came out in 2005 (see also pages 11, 12, 13):
>>
>> https://tf.nist.gov/general/pdf/2013.pdf
>>
>> There was quite a bit of traffic on time-nuts around 2005 when the GOES
>> satellite time service was turned off (and back on, and off, and on, and
>> finally off for good). That left many of us with piles of 468 MHz GOES
>> receivers, antennae, clocks and led to efforts to re-create the RF signals
>> in-home so that GOES clocks would still work. There was even a commercial
>> G2G (GPS to GOES) translator.
>>
>> Anyway, I asked around about that one-off bicentennial clock in the photo
>> and neither the authors, NIST, or Smithsonian knows where it ended up.
>> There's tons of information on the GOES satellite system and GOES clocks
>> in
>> the NIST T&F archives:
>>
>> https://tf.nist.gov/general/publications.htm
>>
>> Best to search title for GOES, or search author for Hanson. It's a
>> fascinating glimpse into the recent past. Yes, it's sad that GOES (and
>> Omega, and Loran-C) aren't operational anymore, but GPS does such a better
>> job. Plus we now have cable, WiFi, cell phones, the internet, Iridium,
>> etc.
>>
>> If you wanted to build your own Bicentennial GOES Clock, the design was
>> published, including source code -- for its i4004 (!!) CPU. If you have
>> even
>> one minute to spare, see attached image and click on these two PDF's:
>>
>> "Satellite Controlled Digital Clock System (patent)"
>> https://tf.nist.gov/general/pdf/1791.pdf
>>
>> "A Satellite-Controlled Digital Clock (NBS TN-681)"
>> https://tf.nist.gov/general/pdf/452.pdf
>>
>> /tvb
>>
>>
>> ----- Original Message -----
>> From: "Tim Shoppa" <***@gmail.com>
>> To: "Discussion of precise time and frequency measurement"
>> <time-***@lists.febo.com>
>> Sent: Wednesday, August 08, 2018 7:29 PM
>> Subject: [time-nuts] Bicentennial GOES satellite clock
>>
>>
>> See the groovy picture at
>>> https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4847573/figure/
>>> f9-j110-2lom/
>>>
>>> If anyone knows the whereabouts or history of the bicentennial GOES time
>>> clock display, please let me know!
>>>
>>> Tim N3QE
>>>
>>
>>
>>
>> _______________________________________________
>> time-nuts mailing list -- time-***@lists.febo.com
>> To unsubscribe, go to
>> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
>> and follow the instructions there.
>>
>> _______________________________________________
>> time-nuts mailing list -- time-***@lists.febo.com
>> To unsubscribe, go to
>> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
>> and follow the instructions there.
>>
>
> --
> Dr. Don Latham
> PO Box 404, Frenchtown, MT, 59834
> VOX: 406-626-4304
>
>
>
> _______________________________________________
> time-nuts mailing list -- time-***@lists.febo.com
> To unsubscribe, go to http://lists.febo.com/mailman/
> listinfo/time-nuts_lists.febo.com
> and follow the instructions there.
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ew via time-nuts
2018-08-10 18:29:54 UTC
Permalink
 
NIST total budget for 2017 was close to 965 Million, I was curios trying to find out what the Time and Frequency Division  portion was. No Luck. Does any one know?Thanks   Bert Kehren
_______________________________________________
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and follow the instructi
Magnus Danielson
2018-08-10 19:11:06 UTC
Permalink
Bert,

The closes I come is this, burried in the line of Funamental Measurements:
https://www.nist.gov/fy-2019-presidential-budget-request-summary/budget-tables

It doesn't get more detailed than that.

The T&F work is relatively small group in the big NIST.

Cheers,
Magnus

On 08/10/2018 08:29 PM, ew via time-nuts wrote:
>  
> NIST total budget for 2017 was close to 965 Million, I was curios trying to find out what the Time and Frequency Division  portion was. No Luck. Does any one know?Thanks   Bert Kehren
> _______________________________________________
> time-nuts mailing list -- time-***@lists.febo.com
> To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> and follow the instructions there.
>

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Robert LaJeunesse
2018-08-10 19:45:20 UTC
Permalink
I'd say it does get more detailed, with the $49M in cuts described generally in groups here:

https://www.nist.gov/director/fy-2019-presidential-budget-request-summary/fundamental-measurement-quantum-science-and

One item: "-$6.3 million supporting fundamental measurement dissemination, including the shutdown of NIST radio stations in Colorado and Hawaii"

Looks like some of your friends might be looking for work. Not good.

Bob L.


> Sent: Friday, August 10, 2018 at 3:11 PM
> From: "Magnus Danielson" <***@rubidium.dyndns.org>
> To: time-***@lists.febo.com
> Cc: ***@rubidium.se
> Subject: Re: [time-nuts] NIST
>
> Bert,
>
> The closes I come is this, burried in the line of Funamental Measurements:
> https://www.nist.gov/fy-2019-presidential-budget-request-summary/budget-tables
>
> It doesn't get more detailed than that.
>
> The T&F work is relatively small group in the big NIST.
>
> Cheers,
> Magnus
>
> On 08/10/2018 08:29 PM, ew via time-nuts wrote:
> >  
> > NIST total budget for 2017 was close to 965 Million, I was curios trying to find out what the Time and Frequency Division  portion was. No Luck. Does any one know?Thanks   Bert Kehren
> > _______________________________________________
> > time-nuts mailing list -- time-***@lists.febo.com
> > To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> > and follow the instructions there.
> >
>
> _______________________________________________
> time-nuts mailing list -- time-***@lists.febo.com
> To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> and follow the instructions there.
>

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Dana Whitlow
2018-08-10 20:34:03 UTC
Permalink
I wonder if anybody will market a GPS-to-WWVB translator?

Dana


On Fri, Aug 10, 2018 at 2:45 PM, Robert LaJeunesse <***@mail.com>
wrote:

> I'd say it does get more detailed, with the $49M in cuts described
> generally in groups here:
>
> https://www.nist.gov/director/fy-2019-presidential-budget-
> request-summary/fundamental-measurement-quantum-science-and
>
> One item: "-$6.3 million supporting fundamental measurement dissemination,
> including the shutdown of NIST radio stations in Colorado and Hawaii"
>
> Looks like some of your friends might be looking for work. Not good.
>
> Bob L.
>
>
> > Sent: Friday, August 10, 2018 at 3:11 PM
> > From: "Magnus Danielson" <***@rubidium.dyndns.org>
> > To: time-***@lists.febo.com
> > Cc: ***@rubidium.se
> > Subject: Re: [time-nuts] NIST
> >
> > Bert,
> >
> > The closes I come is this, burried in the line of Funamental
> Measurements:
> > https://www.nist.gov/fy-2019-presidential-budget-request-
> summary/budget-tables
> >
> > It doesn't get more detailed than that.
> >
> > The T&F work is relatively small group in the big NIST.
> >
> > Cheers,
> > Magnus
> >
> > On 08/10/2018 08:29 PM, ew via time-nuts wrote:
> > >
> > > NIST total budget for 2017 was close to 965 Million, I was curios
> trying to find out what the Time and Frequency Division portion was. No
> Luck. Does any one know?Thanks Bert Kehren
> > > _______________________________________________
> > > time-nuts mailing list -- time-***@lists.febo.com
> > > To unsubscribe, go to http://lists.febo.com/mailman/
> listinfo/time-nuts_lists.febo.com
> > > and follow the instructions there.
> > >
> >
> > _______________________________________________
> > time-nuts mailing list -- time-***@lists.febo.com
> > To unsubscribe, go to http://lists.febo.com/mailman/
> listinfo/time-nuts_lists.febo.com
> > and follow the instructions there.
> >
>
> _______________________________________________
> time-nuts mailing list -- time-***@lists.febo.com
> To unsubscribe, go to http://lists.febo.com/mailman/
> listinfo/time-nuts_lists.febo.com
> and follow the instructions there.
>
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Andy Backus
2018-08-10 21:05:14 UTC
Permalink
I have a very simple circuit for a (microwatt) 60 kHz transmitter that takes a digital input (only needs someone to calculate out the WWVB code from a GPS clock). The biggest problem I find with my WWVB clocks is getting a good signal, which is highly depend on location in the house and orientation of the device's antenna. So I have one WWVB receiver in a good place and key my little transmitter as a "translator" elsewhere in the house.


Andy Backus


________________________________
From: time-nuts <time-nuts-***@lists.febo.com> on behalf of Dana Whitlow <***@gmail.com>
Sent: Friday, August 10, 2018 1:34 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] NIST

I wonder if anybody will market a GPS-to-WWVB translator?

Dana


On Fri, Aug 10, 2018 at 2:45 PM, Robert LaJeunesse <***@mail.com>
wrote:

> I'd say it does get more detailed, with the $49M in cuts described
> generally in groups here:
>
> https://www.nist.gov/director/fy-2019-presidential-budget-
> request-summary/fundamental-measurement-quantum-science-and
>
> One item: "-$6.3 million supporting fundamental measurement dissemination,
> including the shutdown of NIST radio stations in Colorado and Hawaii"
>
> Looks like some of your friends might be looking for work. Not good.
>
> Bob L.
>
>
> > Sent: Friday, August 10, 2018 at 3:11 PM
> > From: "Magnus Danielson" <***@rubidium.dyndns.org>
> > To: time-***@lists.febo.com
> > Cc: ***@rubidium.se
> > Subject: Re: [time-nuts] NIST
> >
> > Bert,
> >
> > The closes I come is this, burried in the line of Funamental
> Measurements:
> > https://www.nist.gov/fy-2019-presidential-budget-request-
> summary/budget-tables
> >
> > It doesn't get more detailed than that.
> >
> > The T&F work is relatively small group in the big NIST.
> >
> > Cheers,
> > Magnus
> >
> > On 08/10/2018 08:29 PM, ew via time-nuts wrote:
> > >
> > > NIST total budget for 2017 was close to 965 Million, I was curios
> trying to find out what the Time and Frequency Division portion was. No
> Luck. Does any one know?Thanks Bert Kehren
> > > _______________________________________________
> > > time-nuts mailing list -- time-***@lists.febo.com
> > > To unsubscribe, go to http://lists.febo.com/mailman/
> listinfo/time-nuts_lists.febo.com
> > > and follow the instructions there.
> > >
> >
> > _______________________________________________
> > time-nuts mailing list -- time-***@lists.febo.com
> > To unsubscribe, go to http://lists.febo.com/mailman/
> listinfo/time-nuts_lists.febo.com
> > and follow the instructions there.
> >
>
> _______________________________________________
> time-nuts mailing list -- time-***@lists.febo.com
> To unsubscribe, go to http://lists.febo.com/mailman/
> listinfo/time-nuts_lists.febo.com
> and follow the instructions there.
>
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Larry Sampas
2018-08-10 23:56:50 UTC
Permalink
My favorite RFI (Request for Information):
https://www.fbo.gov/index?s=opportunity&mode=form&id=4f5c8b176af03d89abb1a318624c944b&tab=core&_cview=0

The public comments should be around someplace.

Larry Sampas

On Fri, Aug 10, 2018 at 5:05 PM, Andy Backus <***@msn.com> wrote:

> I have a very simple circuit for a (microwatt) 60 kHz transmitter that
> takes a digital input (only needs someone to calculate out the WWVB code
> from a GPS clock). The biggest problem I find with my WWVB clocks is
> getting a good signal, which is highly depend on location in the house and
> orientation of the device's antenna. So I have one WWVB receiver in a good
> place and key my little transmitter as a "translator" elsewhere in the
> house.
>
>
> Andy Backus
>
>
> ________________________________
> From: time-nuts <time-nuts-***@lists.febo.com> on behalf of Dana
> Whitlow <***@gmail.com>
> Sent: Friday, August 10, 2018 1:34 PM
> To: Discussion of precise time and frequency measurement
> Subject: Re: [time-nuts] NIST
>
> I wonder if anybody will market a GPS-to-WWVB translator?
>
> Dana
>
>
> On Fri, Aug 10, 2018 at 2:45 PM, Robert LaJeunesse <***@mail.com>
> wrote:
>
> > I'd say it does get more detailed, with the $49M in cuts described
> > generally in groups here:
> >
> > https://www.nist.gov/director/fy-2019-presidential-budget-
> > request-summary/fundamental-measurement-quantum-science-and
> >
> > One item: "-$6.3 million supporting fundamental measurement
> dissemination,
> > including the shutdown of NIST radio stations in Colorado and Hawaii"
> >
> > Looks like some of your friends might be looking for work. Not good.
> >
> > Bob L.
> >
> >
> > > Sent: Friday, August 10, 2018 at 3:11 PM
> > > From: "Magnus Danielson" <***@rubidium.dyndns.org>
> > > To: time-***@lists.febo.com
> > > Cc: ***@rubidium.se
> > > Subject: Re: [time-nuts] NIST
> > >
> > > Bert,
> > >
> > > The closes I come is this, burried in the line of Funamental
> > Measurements:
> > > https://www.nist.gov/fy-2019-presidential-budget-request-
> > summary/budget-tables
> > >
> > > It doesn't get more detailed than that.
> > >
> > > The T&F work is relatively small group in the big NIST.
> > >
> > > Cheers,
> > > Magnus
> > >
> > > On 08/10/2018 08:29 PM, ew via time-nuts wrote:
> > > >
> > > > NIST total budget for 2017 was close to 965 Million, I was curios
> > trying to find out what the Time and Frequency Division portion was. No
> > Luck. Does any one know?Thanks Bert Kehren
> > > > _______________________________________________
> > > > time-nuts mailing list -- time-***@lists.febo.com
> > > > To unsubscribe, go to http://lists.febo.com/mailman/
> > listinfo/time-nuts_lists.febo.com
> > > > and follow the instructions there.
> > > >
> > >
> > > _______________________________________________
> > > time-nuts mailing list -- time-***@lists.febo.com
> > > To unsubscribe, go to http://lists.febo.com/mailman/
> > listinfo/time-nuts_lists.febo.com
> > > and follow the instructions there.
> > >
> >
> > _______________________________________________
> > time-nuts mailing list -- time-***@lists.febo.com
> > To unsubscribe, go to http://lists.febo.com/mailman/
> > listinfo/time-nuts_lists.febo.com
> > and follow the instructions there.
> >
> _______________________________________________
> time-nuts mailing list -- time-***@lists.febo.com
> To unsubscribe, go to http://lists.febo.com/mailman/
> listinfo/time-nuts_lists.febo.com
> and follow the instructions there.
> _______________________________________________
> time-nuts mailing list -- time-***@lists.febo.com
> To unsubscribe, go to http://lists.febo.com/mailman/
> listinfo/time-nuts_lists.febo.com
> and follow the instructions there.
>
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Steven Sommars
2018-08-11 02:56:27 UTC
Permalink
I found the public comments from Microsemi
<https://www.nist.gov/sites/default/files/documents/2017/05/09/NIST-RFI-Internet-Time-Service-response.pdf>,
but couldn't locate my response. At one time the full set of RFI public
responses was on-line.

The NIST 60 kHz time service is widely used by inexpensive clocks, but I
find little use by public NTP servers.




On Fri, Aug 10, 2018 at 6:56 PM, Larry Sampas <***@larrysampas.com> wrote:

> My favorite RFI (Request for Information):
> https://www.fbo.gov/index?s=opportunity&mode=form&id=
> 4f5c8b176af03d89abb1a318624c944b&tab=core&_cview=0
>
> The public comments should be around someplace.
>
> Larry Sampas
>
> On Fri, Aug 10, 2018 at 5:05 PM, Andy Backus <***@msn.com> wrote:
>
> > I have a very simple circuit for a (microwatt) 60 kHz transmitter that
> > takes a digital input (only needs someone to calculate out the WWVB code
> > from a GPS clock). The biggest problem I find with my WWVB clocks is
> > getting a good signal, which is highly depend on location in the house
> and
> > orientation of the device's antenna. So I have one WWVB receiver in a
> good
> > place and key my little transmitter as a "translator" elsewhere in the
> > house.
> >
> >
> > Andy Backus
> >
> >
> > ________________________________
> > From: time-nuts <time-nuts-***@lists.febo.com> on behalf of Dana
> > Whitlow <***@gmail.com>
> > Sent: Friday, August 10, 2018 1:34 PM
> > To: Discussion of precise time and frequency measurement
> > Subject: Re: [time-nuts] NIST
> >
> > I wonder if anybody will market a GPS-to-WWVB translator?
> >
> > Dana
> >
> >
> > On Fri, Aug 10, 2018 at 2:45 PM, Robert LaJeunesse <***@mail.com>
> > wrote:
> >
> > > I'd say it does get more detailed, with the $49M in cuts described
> > > generally in groups here:
> > >
> > > https://www.nist.gov/director/fy-2019-presidential-budget-
> > > request-summary/fundamental-measurement-quantum-science-and
> > >
> > > One item: "-$6.3 million supporting fundamental measurement
> > dissemination,
> > > including the shutdown of NIST radio stations in Colorado and Hawaii"
> > >
> > > Looks like some of your friends might be looking for work. Not good.
> > >
> > > Bob L.
> > >
> > >
> > > > Sent: Friday, August 10, 2018 at 3:11 PM
> > > > From: "Magnus Danielson" <***@rubidium.dyndns.org>
> > > > To: time-***@lists.febo.com
> > > > Cc: ***@rubidium.se
> > > > Subject: Re: [time-nuts] NIST
> > > >
> > > > Bert,
> > > >
> > > > The closes I come is this, burried in the line of Funamental
> > > Measurements:
> > > > https://www.nist.gov/fy-2019-presidential-budget-request-
> > > summary/budget-tables
> > > >
> > > > It doesn't get more detailed than that.
> > > >
> > > > The T&F work is relatively small group in the big NIST.
> > > >
> > > > Cheers,
> > > > Magnus
> > > >
> > > > On 08/10/2018 08:29 PM, ew via time-nuts wrote:
> > > > >
> > > > > NIST total budget for 2017 was close to 965 Million, I was curios
> > > trying to find out what the Time and Frequency Division portion was.
> No
> > > Luck. Does any one know?Thanks Bert Kehren
> > > > > _______________________________________________
> > > > > time-nuts mailing list -- time-***@lists.febo.com
> > > > > To unsubscribe, go to http://lists.febo.com/mailman/
> > > listinfo/time-nuts_lists.febo.com
> > > > > and follow the instructions there.
> > > > >
> > > >
> > > > _______________________________________________
> > > > time-nuts mailing list -- time-***@lists.febo.com
> > > > To unsubscribe, go to http://lists.febo.com/mailman/
> > > listinfo/time-nuts_lists.febo.com
> > > > and follow the instructions there.
> > > >
> > >
> > > _______________________________________________
> > > time-nuts mailing list -- time-***@lists.febo.com
> > > To unsubscribe, go to http://lists.febo.com/mailman/
> > > listinfo/time-nuts_lists.febo.com
> > > and follow the instructions there.
> > >
> > _______________________________________________
> > time-nuts mailing list -- time-***@lists.febo.com
> > To unsubscribe, go to http://lists.febo.com/mailman/
> > listinfo/time-nuts_lists.febo.com
> > and follow the instructions there.
> > _______________________________________________
> > time-nuts mailing list -- time-***@lists.febo.com
> > To unsubscribe, go to http://lists.febo.com/mailman/
> > listinfo/time-nuts_lists.febo.com
> > and follow the instructions there.
> >
> _______________________________________________
> time-nuts mailing list -- time-***@lists.febo.com
> To unsubscribe, go to http://lists.febo.com/mailman/
> listinfo/time-nuts_lists.febo.com
> and follow the instructions there.
>
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paul swed
2018-08-11 17:47:28 UTC
Permalink
This one almost slipped by me.
I see NIST seems to have taken down the link or details.
So they want to shut down the services. I suppose that makes some sense.
But would like to see what that means. LF and HF...
Regards
Paul
WB8TSL

On Fri, Aug 10, 2018 at 10:56 PM, Steven Sommars <***@gmail.com>
wrote:

> I found the public comments from Microsemi
> <https://www.nist.gov/sites/default/files/documents/2017/
> 05/09/NIST-RFI-Internet-Time-Service-response.pdf>,
> but couldn't locate my response. At one time the full set of RFI public
> responses was on-line.
>
> The NIST 60 kHz time service is widely used by inexpensive clocks, but I
> find little use by public NTP servers.
>
>
>
>
> On Fri, Aug 10, 2018 at 6:56 PM, Larry Sampas <***@larrysampas.com>
> wrote:
>
> > My favorite RFI (Request for Information):
> > https://www.fbo.gov/index?s=opportunity&mode=form&id=
> > 4f5c8b176af03d89abb1a318624c944b&tab=core&_cview=0
> >
> > The public comments should be around someplace.
> >
> > Larry Sampas
> >
> > On Fri, Aug 10, 2018 at 5:05 PM, Andy Backus <***@msn.com>
> wrote:
> >
> > > I have a very simple circuit for a (microwatt) 60 kHz transmitter that
> > > takes a digital input (only needs someone to calculate out the WWVB
> code
> > > from a GPS clock). The biggest problem I find with my WWVB clocks is
> > > getting a good signal, which is highly depend on location in the house
> > and
> > > orientation of the device's antenna. So I have one WWVB receiver in a
> > good
> > > place and key my little transmitter as a "translator" elsewhere in the
> > > house.
> > >
> > >
> > > Andy Backus
> > >
> > >
> > > ________________________________
> > > From: time-nuts <time-nuts-***@lists.febo.com> on behalf of Dana
> > > Whitlow <***@gmail.com>
> > > Sent: Friday, August 10, 2018 1:34 PM
> > > To: Discussion of precise time and frequency measurement
> > > Subject: Re: [time-nuts] NIST
> > >
> > > I wonder if anybody will market a GPS-to-WWVB translator?
> > >
> > > Dana
> > >
> > >
> > > On Fri, Aug 10, 2018 at 2:45 PM, Robert LaJeunesse <
> ***@mail.com>
> > > wrote:
> > >
> > > > I'd say it does get more detailed, with the $49M in cuts described
> > > > generally in groups here:
> > > >
> > > > https://www.nist.gov/director/fy-2019-presidential-budget-
> > > > request-summary/fundamental-measurement-quantum-science-and
> > > >
> > > > One item: "-$6.3 million supporting fundamental measurement
> > > dissemination,
> > > > including the shutdown of NIST radio stations in Colorado and Hawaii"
> > > >
> > > > Looks like some of your friends might be looking for work. Not good.
> > > >
> > > > Bob L.
> > > >
> > > >
> > > > > Sent: Friday, August 10, 2018 at 3:11 PM
> > > > > From: "Magnus Danielson" <***@rubidium.dyndns.org>
> > > > > To: time-***@lists.febo.com
> > > > > Cc: ***@rubidium.se
> > > > > Subject: Re: [time-nuts] NIST
> > > > >
> > > > > Bert,
> > > > >
> > > > > The closes I come is this, burried in the line of Funamental
> > > > Measurements:
> > > > > https://www.nist.gov/fy-2019-presidential-budget-request-
> > > > summary/budget-tables
> > > > >
> > > > > It doesn't get more detailed than that.
> > > > >
> > > > > The T&F work is relatively small group in the big NIST.
> > > > >
> > > > > Cheers,
> > > > > Magnus
> > > > >
> > > > > On 08/10/2018 08:29 PM, ew via time-nuts wrote:
> > > > > >
> > > > > > NIST total budget for 2017 was close to 965 Million, I was curios
> > > > trying to find out what the Time and Frequency Division portion was.
> > No
> > > > Luck. Does any one know?Thanks Bert Kehren
> > > > > > _______________________________________________
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Tom Van Baak
2018-08-11 22:43:46 UTC
Permalink
> I wonder if anybody will market a GPS-to-WWVB translator?
> Dana

You can find lots of these projects on the web: in the time-nuts archives, eevblog, hackaday, or sometimes completed multi-band kits (WWVB / DCF77 / JJY) on eBay.

Search for a couple of words like signal wwvb simulator generator translator emulator transmitter

An example of a well engineered product (no longer available?) is: https://unusualelectronics.co.uk/products/chronvertor/

An example of a quick hack (open source) is: https://hackaday.com/2014/03/22/build-your-own-radio-clock-transmitter/

There are dozens more.

/tvb


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Andy Backus
2018-08-11 23:31:15 UTC
Permalink
To answer Dana's question, there are many projects on the web (as Tom has pointed out), but very few, think, will answer the question in total.


For the DYI person, I think a GPS module from Adafruit, an Arduino, and a down-and-dirty little transmitter like mine or the one in Tom's second link will do the trick. Writing the software will be fun (beginning with simply counting the PPS from the GPS).


acb


________________________________

> I wonder if anybody will market a GPS-to-WWVB translator?
> Dana


You can find lots of these projects on the web: in the time-nuts archives, eevblog, hackaday, or sometimes completed multi-band kits (WWVB / DCF77 / JJY) on eBay.

Search for a couple of words like signal wwvb simulator generator translator emulator transmitter

An example of a well engineered product (no longer available?) is: https://unusualelectronics.co.uk/products/chronvertor/


An example of a quick hack (open source) is: https://hackaday.com/2014/03/22/build-your-own-radio-clock-transmitter/

There are dozens more.

/tvb


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jimlux
2018-08-12 01:00:10 UTC
Permalink
On 8/10/18 12:45 PM, Robert LaJeunesse wrote:
> I'd say it does get more detailed, with the $49M in cuts described generally in groups here:
>
> https://www.nist.gov/director/fy-2019-presidential-budget-request-summary/fundamental-measurement-quantum-science-and
>
> One item: "-$6.3 million supporting fundamental measurement dissemination, including the shutdown of NIST radio stations in Colorado and Hawaii"
>

I wonder if that's WWVB, or WWV & WWVH

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Bob kb8tq
2018-08-12 01:08:46 UTC
Permalink
Hi

One would *guess* that stopping WWVB (and killing mom and pop’s “atomic clocks”) would not be a reasonable thing to do.
It gets a lot of voters mad. I doubt that very many voters (percentage wise) would notice WWV and WWVH going away ….

Bob

> On Aug 11, 2018, at 9:00 PM, jimlux <***@earthlink.net> wrote:
>
> On 8/10/18 12:45 PM, Robert LaJeunesse wrote:
>> I'd say it does get more detailed, with the $49M in cuts described generally in groups here:
>> https://www.nist.gov/director/fy-2019-presidential-budget-request-summary/fundamental-measurement-quantum-science-and
>> One item: "-$6.3 million supporting fundamental measurement dissemination, including the shutdown of NIST radio stations in Colorado and Hawaii"
>
> I wonder if that's WWVB, or WWV & WWVH
>
> _______________________________________________
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Bob Albert via time-nuts
2018-08-12 01:12:43 UTC
Permalink
With any luck, the current administration will successfully push the USA down technically.  Denying global warming, shutting off time signals, and so on, is great stuff.
On Saturday, August 11, 2018, 6:10:12 PM PDT, Bob kb8tq <***@n1k.org> wrote:

Hi

One would *guess* that stopping WWVB (and killing mom and pop’s “atomic clocks”) would not be a reasonable thing to do.
It gets a lot of voters mad. I doubt that very many voters (percentage wise) would notice WWV and WWVH going away ….

Bob

> On Aug 11, 2018, at 9:00 PM, jimlux <***@earthlink.net> wrote:
>
> On 8/10/18 12:45 PM, Robert LaJeunesse wrote:
>> I'd say it does get more detailed, with the $49M in cuts described generally in groups here:
>> https://www.nist.gov/director/fy-2019-presidential-budget-request-summary/fundamental-measurement-quantum-science-and
>> One item: "-$6.3 million supporting fundamental measurement dissemination, including the shutdown of NIST radio stations in Colorado and Hawaii"
>
> I wonder if that's WWVB, or WWV & WWVH
>
> _______________________________________________
> time-nuts mailing list -- time-***@lists.febo.com
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Dana Whitlow
2018-08-12 02:48:35 UTC
Permalink
I fear the worst. The line in the website simply stated something like
"shutting down
the transmitters in Colorado and Hawaii", which would seem to include the
whole
enchilada.

For the wall clocks, GPS should work well if people are willing to go to
battery-
backed AC power. But not so good for wristwatches, where the expectation
is to
run at uW power levels. I for one would be very irritated at having to
take my watch
off my wrist and put it on a charging stand every night. So if this
shutdown comes
to pass, I'll be looking for an inexpensive GPS-to-WWVB converter, or at
least
plans for building one.

Dana


On Sat, Aug 11, 2018 at 8:12 PM, Bob Albert via time-nuts <
time-***@lists.febo.com> wrote:

> With any luck, the current administration will successfully push the USA
> down technically. Denying global warming, shutting off time signals, and
> so on, is great stuff.
> On Saturday, August 11, 2018, 6:10:12 PM PDT, Bob kb8tq <***@n1k.org>
> wrote:
>
> Hi
>
> One would *guess* that stopping WWVB (and killing mom and pop’s “atomic
> clocks”) would not be a reasonable thing to do.
> It gets a lot of voters mad. I doubt that very many voters (percentage
> wise) would notice WWV and WWVH going away ….
>
> Bob
>
> > On Aug 11, 2018, at 9:00 PM, jimlux <***@earthlink.net> wrote:
> >
> > On 8/10/18 12:45 PM, Robert LaJeunesse wrote:
> >> I'd say it does get more detailed, with the $49M in cuts described
> generally in groups here:
> >> https://www.nist.gov/director/fy-2019-presidential-budget-
> request-summary/fundamental-measurement-quantum-science-and
> >> One item: "-$6.3 million supporting fundamental measurement
> dissemination, including the shutdown of NIST radio stations in Colorado
> and Hawaii"
> >
> > I wonder if that's WWVB, or WWV & WWVH
> >
> > _______________________________________________
> > time-nuts mailing list -- time-***@lists.febo.com
> > To unsubscribe, go to http://lists.febo.com/mailman/
> listinfo/time-nuts_lists.febo.com
> > and follow the instructions there.
>
>
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paul swed
2018-08-12 18:20:53 UTC
Permalink
Like all of you I have a few wwvb clocks that work pretty well here in
Boston.
Certainly have written enough wwvb stuff and created various wwvb projects
that I will have to get back into it again.
I did look at the cron-verter. Have to say it has a lot of nice features.
Unfortunately it hasn't been available for a year or so. (Getting lazy)
The good news is the AM modulation of wwb is very easy to create.
Regards
Paul
WB8TSL

On Sat, Aug 11, 2018 at 10:48 PM, Dana Whitlow <***@gmail.com>
wrote:

> I fear the worst. The line in the website simply stated something like
> "shutting down
> the transmitters in Colorado and Hawaii", which would seem to include the
> whole
> enchilada.
>
> For the wall clocks, GPS should work well if people are willing to go to
> battery-
> backed AC power. But not so good for wristwatches, where the expectation
> is to
> run at uW power levels. I for one would be very irritated at having to
> take my watch
> off my wrist and put it on a charging stand every night. So if this
> shutdown comes
> to pass, I'll be looking for an inexpensive GPS-to-WWVB converter, or at
> least
> plans for building one.
>
> Dana
>
>
> On Sat, Aug 11, 2018 at 8:12 PM, Bob Albert via time-nuts <
> time-***@lists.febo.com> wrote:
>
> > With any luck, the current administration will successfully push the USA
> > down technically. Denying global warming, shutting off time signals, and
> > so on, is great stuff.
> > On Saturday, August 11, 2018, 6:10:12 PM PDT, Bob kb8tq <
> ***@n1k.org>
> > wrote:
> >
> > Hi
> >
> > One would *guess* that stopping WWVB (and killing mom and pop’s “atomic
> > clocks”) would not be a reasonable thing to do.
> > It gets a lot of voters mad. I doubt that very many voters (percentage
> > wise) would notice WWV and WWVH going away ….
> >
> > Bob
> >
> > > On Aug 11, 2018, at 9:00 PM, jimlux <***@earthlink.net> wrote:
> > >
> > > On 8/10/18 12:45 PM, Robert LaJeunesse wrote:
> > >> I'd say it does get more detailed, with the $49M in cuts described
> > generally in groups here:
> > >> https://www.nist.gov/director/fy-2019-presidential-budget-
> > request-summary/fundamental-measurement-quantum-science-and
> > >> One item: "-$6.3 million supporting fundamental measurement
> > dissemination, including the shutdown of NIST radio stations in Colorado
> > and Hawaii"
> > >
> > > I wonder if that's WWVB, or WWV & WWVH
> > >
> > > _______________________________________________
> > > time-nuts mailing list -- time-***@lists.febo.com
> > > To unsubscribe, go to http://lists.febo.com/mailman/
> > listinfo/time-nuts_lists.febo.com
> > > and follow the instructions there.
> >
> >
> > _______________________________________________
> > time-nuts mailing list -- time-***@lists.febo.com
> > To unsubscribe, go to http://lists.febo.com/mailman/
> > listinfo/time-nuts_lists.febo.com
> > and follow the instructions there.
> >
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> >
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and fo
djl
2018-08-12 18:58:06 UTC
Permalink
Just a word: When budget cuts are announced, the agencies put the most
valued "stuff" to be cut first, such as the Washington monument, etc.
This is a recognized ploy. When the dust settles, all may be well. . .
Don


On 2018-08-12 12:20, paul swed wrote:
> Like all of you I have a few wwvb clocks that work pretty well here in
> Boston.
> Certainly have written enough wwvb stuff and created various wwvb
> projects
> that I will have to get back into it again.
> I did look at the cron-verter. Have to say it has a lot of nice
> features.
> Unfortunately it hasn't been available for a year or so. (Getting lazy)
> The good news is the AM modulation of wwb is very easy to create.
> Regards
> Paul
> WB8TSL
>
> On Sat, Aug 11, 2018 at 10:48 PM, Dana Whitlow <***@gmail.com>
> wrote:
>
>> I fear the worst. The line in the website simply stated something
>> like
>> "shutting down
>> the transmitters in Colorado and Hawaii", which would seem to include
>> the
>> whole
>> enchilada.
>>
>> For the wall clocks, GPS should work well if people are willing to go
>> to
>> battery-
>> backed AC power. But not so good for wristwatches, where the
>> expectation
>> is to
>> run at uW power levels. I for one would be very irritated at having
>> to
>> take my watch
>> off my wrist and put it on a charging stand every night. So if this
>> shutdown comes
>> to pass, I'll be looking for an inexpensive GPS-to-WWVB converter, or
>> at
>> least
>> plans for building one.
>>
>> Dana
>>
>>
>> On Sat, Aug 11, 2018 at 8:12 PM, Bob Albert via time-nuts <
>> time-***@lists.febo.com> wrote:
>>
>> > With any luck, the current administration will successfully push the USA
>> > down technically. Denying global warming, shutting off time signals, and
>> > so on, is great stuff.
>> > On Saturday, August 11, 2018, 6:10:12 PM PDT, Bob kb8tq <
>> ***@n1k.org>
>> > wrote:
>> >
>> > Hi
>> >
>> > One would *guess* that stopping WWVB (and killing mom and pop’s “atomic
>> > clocks”) would not be a reasonable thing to do.
>> > It gets a lot of voters mad. I doubt that very many voters (percentage
>> > wise) would notice WWV and WWVH going away ….
>> >
>> > Bob
>> >
>> > > On Aug 11, 2018, at 9:00 PM, jimlux <***@earthlink.net> wrote:
>> > >
>> > > On 8/10/18 12:45 PM, Robert LaJeunesse wrote:
>> > >> I'd say it does get more detailed, with the $49M in cuts described
>> > generally in groups here:
>> > >> https://www.nist.gov/director/fy-2019-presidential-budget-
>> > request-summary/fundamental-measurement-quantum-science-and
>> > >> One item: "-$6.3 million supporting fundamental measurement
>> > dissemination, including the shutdown of NIST radio stations in Colorado
>> > and Hawaii"
>> > >
>> > > I wonder if that's WWVB, or WWV & WWVH
>> > >
>> > > _______________________________________________
>> > > time-nuts mailing list -- time-***@lists.febo.com
>> > > To unsubscribe, go to http://lists.febo.com/mailman/
>> > listinfo/time-nuts_lists.febo.com
>> > > and follow the instructions there.
>> >
>> >
>> > _______________________________________________
>> > time-nuts mailing list -- time-***@lists.febo.com
>> > To unsubscribe, go to http://lists.febo.com/mailman/
>> > listinfo/time-nuts_lists.febo.com
>> > and follow the instructions there.
>> >
>> > _______________________________________________
>> > time-nuts mailing list -- time-***@lists.febo.com
>> > To unsubscribe, go to http://lists.febo.com/mailman/
>> > listinfo/time-nuts_lists.febo.com
>> > and follow the instructions there.
>> >
>> _______________________________________________
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>>
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--
Dr. Don Latham
PO Box 404, Frenchtown, MT, 59834
VOX: 406-626-4304


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Wes
2018-08-12 20:19:07 UTC
Permalink
Yep, just like "government shutdowns" where all non-essential people stay home.
(I always wondered why, it they are non-essential they are on the payroll in the
first place, but what do I know, I'm just a taxpayer.)  But what gets shut down
first are things like National Parks, which have immediate effect on lots of people.

What are the effects on the budget of running WWV/WWVB?  The electric bill I
would guess.  When John Q. Public's "atomic clock" stops working, they'll find a
way to pay the bill.

Wes

On 8/12/2018 11:58 AM, djl wrote:
> Just a word:   When budget cuts are announced, the agencies put the most
> valued "stuff" to be cut first, such as the Washington monument, etc. This is
> a recognized ploy. When the dust settles, all may be well. . .
> Don


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paul swed
2018-08-12 20:47:25 UTC
Permalink
Well if the old LF and HF signals go away I am on for yet another wwvb
project and wwv. What the heck.
Creating a AM wwvb is really pretty easy and in fact I have done that.
Can't remember what code that was.
Pretty sure it was basic on SXb2. But the good news is the old BPSK code
isn't needed so it really becomes easy.
The BPSK coder was seriously complicated. (That was the cheatin dePSKr)
So it would be GPS to WWVB code. Have to think about the DST thing. Thats
always a bit messy.

Lastly while I am at it there would be a 5 and 10 MHz wwv simulator at
least ticks and minute tone. Looked at voice and thats a bit of a mess.
They seem to just say numbers. Not sure there are modules that say time
from my bit of research.
Of course have to be careful with transmission levels.... Looks like its
time yo look up fcc part 97.

Things to ponder.
Regards
Paul
WB8TSL

On Sun, Aug 12, 2018 at 4:19 PM, Wes <***@triconet.org> wrote:

> Yep, just like "government shutdowns" where all non-essential people stay
> home. (I always wondered why, it they are non-essential they are on the
> payroll in the first place, but what do I know, I'm just a taxpayer.) But
> what gets shut down first are things like National Parks, which have
> immediate effect on lots of people.
>
> What are the effects on the budget of running WWV/WWVB? The electric bill
> I would guess. When John Q. Public's "atomic clock" stops working, they'll
> find a way to pay the bill.
>
> Wes
>
> On 8/12/2018 11:58 AM, djl wrote:
>
>> Just a word: When budget cuts are announced, the agencies put the most
>> valued "stuff" to be cut first, such as the Washington monument, etc. This
>> is a recognized ploy. When the dust settles, all may be well. . .
>> Don
>>
>
>
> _______________________________________________
> time-nuts mailing list -- time-***@lists.febo.com
> To unsubscribe, go to http://lists.febo.com/mailman/
> listinfo/time-nuts_lists.febo.com
> and follow the instructions there.
>
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Andy Backus
2018-08-12 22:01:23 UTC
Permalink
WWV HF transmissions include a 100 Hz subcarrier that gives the info in cw format.


For generating WWVB code I would suggest simply counting seconds to yield days -- the WWVB code takes the day number in the year. Leap year is easy. Just look up the DST start and stop.


acb


________________________________
From: time-nuts <time-nuts-***@lists.febo.com> on behalf of paul swed <***@gmail.com>
Sent: Sunday, August 12, 2018 1:47 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] NIST

Well if the old LF and HF signals go away I am on for yet another wwvb
project and wwv. What the heck.
Creating a AM wwvb is really pretty easy and in fact I have done that.
Can't remember what code that was.
Pretty sure it was basic on SXb2. But the good news is the old BPSK code
isn't needed so it really becomes easy.
The BPSK coder was seriously complicated. (That was the cheatin dePSKr)
So it would be GPS to WWVB code. Have to think about the DST thing. Thats
always a bit messy.

Lastly while I am at it there would be a 5 and 10 MHz wwv simulator at
least ticks and minute tone. Looked at voice and thats a bit of a mess.
They seem to just say numbers. Not sure there are modules that say time
from my bit of research.
Of course have to be careful with transmission levels.... Looks like its
time yo look up fcc part 97.

Things to ponder.
Regards
Paul
WB8TSL

On Sun, Aug 12, 2018 at 4:19 PM, Wes <***@triconet.org> wrote:

> Yep, just like "government shutdowns" where all non-essential people stay
> home. (I always wondered why, it they are non-essential they are on the
> payroll in the first place, but what do I know, I'm just a taxpayer.) But
> what gets shut down first are things like National Parks, which have
> immediate effect on lots of people.
>
> What are the effects on the budget of running WWV/WWVB? The electric bill
> I would guess. When John Q. Public's "atomic clock" stops working, they'll
> find a way to pay the bill.
>
> Wes
>
> On 8/12/2018 11:58 AM, djl wrote:
>
>> Just a word: When budget cuts are announced, the agencies put the most
>> valued "stuff" to be cut first, such as the Washington monument, etc. This
>> is a recognized ploy. When the dust settles, all may be well. . .
>> Don
>>
>
>
> _______________________________________________
> time-nuts mailing list -- time-***@lists.febo.com
> To unsubscribe, go to http://lists.febo.com/mailman/
> listinfo/time-nuts_lists.febo.com
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>
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Joe Dempster
2018-08-12 20:49:52 UTC
Permalink
I hope that defunding is just a ploy and things will remain on the air. I
am concerned this is starting to sound like 2010 when DHS/USCG took eLoran
off the air in the states. This was one of the few things that totally
dismayed me about the Obama administration.

On Sun, Aug 12, 2018 at 2:59 PM djl <***@montana.com> wrote:

> Just a word: When budget cuts are announced, the agencies put the most
> valued "stuff" to be cut first, such as the Washington monument, etc.
> This is a recognized ploy. When the dust settles, all may be well. . .
> Don
>
>
> On 2018-08-12 12:20, paul swed wrote:
> > Like all of you I have a few wwvb clocks that work pretty well here in
> > Boston.
> > Certainly have written enough wwvb stuff and created various wwvb
> > projects
> > that I will have to get back into it again.
> > I did look at the cron-verter. Have to say it has a lot of nice
> > features.
> > Unfortunately it hasn't been available for a year or so. (Getting lazy)
> > The good news is the AM modulation of wwb is very easy to create.
> > Regards
> > Paul
> > WB8TSL
> >
> > On Sat, Aug 11, 2018 at 10:48 PM, Dana Whitlow <***@gmail.com>
> > wrote:
> >
> >> I fear the worst. The line in the website simply stated something
> >> like
> >> "shutting down
> >> the transmitters in Colorado and Hawaii", which would seem to include
> >> the
> >> whole
> >> enchilada.
> >>
> >> For the wall clocks, GPS should work well if people are willing to go
> >> to
> >> battery-
> >> backed AC power. But not so good for wristwatches, where the
> >> expectation
> >> is to
> >> run at uW power levels. I for one would be very irritated at having
> >> to
> >> take my watch
> >> off my wrist and put it on a charging stand every night. So if this
> >> shutdown comes
> >> to pass, I'll be looking for an inexpensive GPS-to-WWVB converter, or
> >> at
> >> least
> >> plans for building one.
> >>
> >> Dana
> >>
> >>
> >> On Sat, Aug 11, 2018 at 8:12 PM, Bob Albert via time-nuts <
> >> time-***@lists.febo.com> wrote:
> >>
> >> > With any luck, the current administration will successfully push the
> USA
> >> > down technically. Denying global warming, shutting off time signals,
> and
> >> > so on, is great stuff.
> >> > On Saturday, August 11, 2018, 6:10:12 PM PDT, Bob kb8tq <
> >> ***@n1k.org>
> >> > wrote:
> >> >
> >> > Hi
> >> >
> >> > One would *guess* that stopping WWVB (and killing mom and pop’s
> “atomic
> >> > clocks”) would not be a reasonable thing to do.
> >> > It gets a lot of voters mad. I doubt that very many voters (percentage
> >> > wise) would notice WWV and WWVH going away ….
> >> >
> >> > Bob
> >> >
> >> > > On Aug 11, 2018, at 9:00 PM, jimlux <***@earthlink.net> wrote:
> >> > >
> >> > > On 8/10/18 12:45 PM, Robert LaJeunesse wrote:
> >> > >> I'd say it does get more detailed, with the $49M in cuts described
> >> > generally in groups here:
> >> > >> https://www.nist.gov/director/fy-2019-presidential-budget-
> >> > request-summary/fundamental-measurement-quantum-science-and
> >> > >> One item: "-$6.3 million supporting fundamental measurement
> >> > dissemination, including the shutdown of NIST radio stations in
> Colorado
> >> > and Hawaii"
> >> > >
> >> > > I wonder if that's WWVB, or WWV & WWVH
> >> > >
> >> > > _______________________________________________
> >> > > time-nuts mailing list -- time-***@lists.febo.com
> >> > > To unsubscribe, go to http://lists.febo.com/mailman/
> >> > listinfo/time-nuts_lists.febo.com
> >> > > and follow the instructions there.
> >> >
> >> >
> >> > _______________________________________________
> >> > time-nuts mailing list -- time-***@lists.febo.com
> >> > To unsubscribe, go to http://lists.febo.com/mailman/
> >> > listinfo/time-nuts_lists.febo.com
> >> > and follow the instructions there.
> >> >
> >> > _______________________________________________
> >> > time-nuts mailing list -- time-***@lists.febo.com
> >> > To unsubscribe, go to http://lists.febo.com/mailman/
> >> > listinfo/time-nuts_lists.febo.com
> >> > and follow the instructions there.
> >> >
> >> _______________________________________________
> >> time-nuts mailing list -- time-***@lists.febo.com
> >> To unsubscribe, go to http://lists.febo.com/mailman/
> >> listinfo/time-nuts_lists.febo.com
> >> and follow the instructions there.
> >>
> > _______________________________________________
> > time-nuts mailing list -- time-***@lists.febo.com
> > To unsubscribe, go to
> > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> > and follow the instructions there.
>
> --
> Dr. Don Latham
> PO Box 404, Frenchtown, MT, 59834
> VOX: 406-626-4304
>
>
> _______________________________________________
> time-nuts mailing list -- time-***@lists.febo.com
> To unsubscribe, go to
> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> and follow the instructions there.
>


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Scott McGrath
2018-08-13 23:48:28 UTC
Permalink
WRT my sextant comment, How many pilots or sailors can navigate by ‘shooting the sun/stars’. They have become dependent on precision navigation systems.

Which of course feeds the thinking by empty suits why do we need lighthouses, buoys, VOR’s and airway beacons because we have the ‘god box’ onboard. Its old fashioned and uncool.

Interestingly enough there have been enough GPS ‘outages’ that the USNO is once again requiring proficiency in celestial navigation in order to graduate food for thought there.

I was initially speaking about loss of GPS due to natural causes. In times of international tension attacking a country by denying its ONLY source of precision time transfer would be a particularly effective tactic and you dont even have to damage the satellites themselves. Just jam L1

As to relying on systems operated by one’s political adversaries that does not seem to be a wise option.

So once again for US’ians time to pick up the phone and put pen to paper and state while the US budget is bloated. This particular item NEEDS to stay. Find a vanity construction project and make it disappear instead. And point out the technical reasons it needs to stay.


Scott


On Aug 12, 2018, at 4:49 PM, Joe Dempster <***@gmail.com> wrote:

I hope that defunding is just a ploy and things will remain on the air. I
am concerned this is starting to sound like 2010 when DHS/USCG took eLoran
off the air in the states. This was one of the few things that totally
dismayed me about the Obama administration.

> On Sun, Aug 12, 2018 at 2:59 PM djl <***@montana.com> wrote:
>
> Just a word: When budget cuts are announced, the agencies put the most
> valued "stuff" to be cut first, such as the Washington monument, etc.
> This is a recognized ploy. When the dust settles, all may be well. . .
> Don
>
>
>> On 2018-08-12 12:20, paul swed wrote:
>> Like all of you I have a few wwvb clocks that work pretty well here in
>> Boston.
>> Certainly have written enough wwvb stuff and created various wwvb
>> projects
>> that I will have to get back into it again.
>> I did look at the cron-verter. Have to say it has a lot of nice
>> features.
>> Unfortunately it hasn't been available for a year or so. (Getting lazy)
>> The good news is the AM modulation of wwb is very easy to create.
>> Regards
>> Paul
>> WB8TSL
>>
>> On Sat, Aug 11, 2018 at 10:48 PM, Dana Whitlow <***@gmail.com>
>> wrote:
>>
>>> I fear the worst. The line in the website simply stated something
>>> like
>>> "shutting down
>>> the transmitters in Colorado and Hawaii", which would seem to include
>>> the
>>> whole
>>> enchilada.
>>>
>>> For the wall clocks, GPS should work well if people are willing to go
>>> to
>>> battery-
>>> backed AC power. But not so good for wristwatches, where the
>>> expectation
>>> is to
>>> run at uW power levels. I for one would be very irritated at having
>>> to
>>> take my watch
>>> off my wrist and put it on a charging stand every night. So if this
>>> shutdown comes
>>> to pass, I'll be looking for an inexpensive GPS-to-WWVB converter, or
>>> at
>>> least
>>> plans for building one.
>>>
>>> Dana
>>>
>>>
>>> On Sat, Aug 11, 2018 at 8:12 PM, Bob Albert via time-nuts <
>>> time-***@lists.febo.com> wrote:
>>>
>>>> With any luck, the current administration will successfully push the
> USA
>>>> down technically. Denying global warming, shutting off time signals,
> and
>>>> so on, is great stuff.
>>>> On Saturday, August 11, 2018, 6:10:12 PM PDT, Bob kb8tq <
>>> ***@n1k.org>
>>>> wrote:
>>>>
>>>> Hi
>>>>
>>>> One would *guess* that stopping WWVB (and killing mom and pop’s
> “atomic
>>>> clocks”) would not be a reasonable thing to do.
>>>> It gets a lot of voters mad. I doubt that very many voters (percentage
>>>> wise) would notice WWV and WWVH going away ….
>>>>
>>>> Bob
>>>>
>>>>> On Aug 11, 2018, at 9:00 PM, jimlux <***@earthlink.net> wrote:
>>>>>
>>>>> On 8/10/18 12:45 PM, Robert LaJeunesse wrote:
>>>>>> I'd say it does get more detailed, with the $49M in cuts described
>>>> generally in groups here:
>>>>>> https://www.nist.gov/director/fy-2019-presidential-budget-
>>>> request-summary/fundamental-measurement-quantum-science-and
>>>>>> One item: "-$6.3 million supporting fundamental measurement
>>>> dissemination, including the shutdown of NIST radio stations in
> Colorado
>>>> and Hawaii"
>>>>>
>>>>> I wonder if that's WWVB, or WWV & WWVH
>>>>>
>>>>> _______________________________________________
>>>>> time-nuts mailing list -- time-***@lists.febo.com
>>>>> To unsubscribe, go to http://lists.febo.com/mailman/
>>>> listinfo/time-nuts_lists.febo.com
>>>>> and follow the instructions there.
>>>>
>>>>
>>>> _______________________________________________
>>>> time-nuts mailing list -- time-***@lists.febo.com
>>>> To unsubscribe, go to http://lists.febo.com/mailman/
>>>> listinfo/time-nuts_lists.febo.com
>>>> and follow the instructions there.
>>>>
>>>> _______________________________________________
>>>> time-nuts mailing list -- time-***@lists.febo.com
>>>> To unsubscribe, go to http://lists.febo.com/mailman/
>>>> listinfo/time-nuts_lists.febo.com
>>>> and follow the instructions there.
>>>>
>>> _______________________________________________
>>> time-nuts mailing list -- time-***@lists.febo.com
>>> To unsubscribe, go to http://lists.febo.com/mailman/
>>> listinfo/time-nuts_lists.febo.com
>>> and follow the instructions there.
>>>
>> _______________________________________________
>> time-nuts mailing list -- time-***@lists.febo.com
>> To unsubscribe, go to
>> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
>> and follow the instructions there.
>
> --
> Dr. Don Latham
> PO Box 404, Frenchtown, MT, 59834
> VOX: 406-626-4304
>
>
> _______________________________________________
> time-nuts mailing list -- time-***@lists.febo.com
> To unsubscribe, go to
> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> and follow the instructions there.
>


--
Joe Dempster
+1 908 413 2889 (mobile)
--
Joe Dempster
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Bob kb8tq
2018-08-14 01:57:29 UTC
Permalink
Hi

Well, if you are worried about L1 jamming, use a receiver that can run on L1/L2/L5 and maybe a few of the other
bands as well. Broadband jammers make *really* good targets, even for a pretty “dumb” weapon / tracking system.
The more bands they cover, the easier they are to spot.

Broadband jamming really isn’t that big a deal. The GPS signal gets buried in the noise and the GPSDO goes into
holdover. If they can’t track down / eliminate the jammer in 24 hours ….. that’s because there’s a very high level of
other radiation ….Again, the jammer is probably pretty far down the list if this is the case.

So yes, if you are trying to navigate in an active war zone, things can get a bit weird. I doubt that any of us will be
trying to come up with timing for our bench under those conditions.

Bob

> On Aug 13, 2018, at 7:48 PM, Scott McGrath <***@gmail.com> wrote:
>
> WRT my sextant comment, How many pilots or sailors can navigate by ‘shooting the sun/stars’. They have become dependent on precision navigation systems.
>
> Which of course feeds the thinking by empty suits why do we need lighthouses, buoys, VOR’s and airway beacons because we have the ‘god box’ onboard. Its old fashioned and uncool.
>
> Interestingly enough there have been enough GPS ‘outages’ that the USNO is once again requiring proficiency in celestial navigation in order to graduate food for thought there.
>
> I was initially speaking about loss of GPS due to natural causes. In times of international tension attacking a country by denying its ONLY source of precision time transfer would be a particularly effective tactic and you dont even have to damage the satellites themselves. Just jam L1
>
> As to relying on systems operated by one’s political adversaries that does not seem to be a wise option.
>
> So once again for US’ians time to pick up the phone and put pen to paper and state while the US budget is bloated. This particular item NEEDS to stay. Find a vanity construction project and make it disappear instead. And point out the technical reasons it needs to stay.
>
>
> Scott
>
>
> On Aug 12, 2018, at 4:49 PM, Joe Dempster <***@gmail.com> wrote:
>
> I hope that defunding is just a ploy and things will remain on the air. I
> am concerned this is starting to sound like 2010 when DHS/USCG took eLoran
> off the air in the states. This was one of the few things that totally
> dismayed me about the Obama administration.
>
>> On Sun, Aug 12, 2018 at 2:59 PM djl <***@montana.com> wrote:
>>
>> Just a word: When budget cuts are announced, the agencies put the most
>> valued "stuff" to be cut first, such as the Washington monument, etc.
>> This is a recognized ploy. When the dust settles, all may be well. . .
>> Don
>>
>>
>>> On 2018-08-12 12:20, paul swed wrote:
>>> Like all of you I have a few wwvb clocks that work pretty well here in
>>> Boston.
>>> Certainly have written enough wwvb stuff and created various wwvb
>>> projects
>>> that I will have to get back into it again.
>>> I did look at the cron-verter. Have to say it has a lot of nice
>>> features.
>>> Unfortunately it hasn't been available for a year or so. (Getting lazy)
>>> The good news is the AM modulation of wwb is very easy to create.
>>> Regards
>>> Paul
>>> WB8TSL
>>>
>>> On Sat, Aug 11, 2018 at 10:48 PM, Dana Whitlow <***@gmail.com>
>>> wrote:
>>>
>>>> I fear the worst. The line in the website simply stated something
>>>> like
>>>> "shutting down
>>>> the transmitters in Colorado and Hawaii", which would seem to include
>>>> the
>>>> whole
>>>> enchilada.
>>>>
>>>> For the wall clocks, GPS should work well if people are willing to go
>>>> to
>>>> battery-
>>>> backed AC power. But not so good for wristwatches, where the
>>>> expectation
>>>> is to
>>>> run at uW power levels. I for one would be very irritated at having
>>>> to
>>>> take my watch
>>>> off my wrist and put it on a charging stand every night. So if this
>>>> shutdown comes
>>>> to pass, I'll be looking for an inexpensive GPS-to-WWVB converter, or
>>>> at
>>>> least
>>>> plans for building one.
>>>>
>>>> Dana
>>>>
>>>>
>>>> On Sat, Aug 11, 2018 at 8:12 PM, Bob Albert via time-nuts <
>>>> time-***@lists.febo.com> wrote:
>>>>
>>>>> With any luck, the current administration will successfully push the
>> USA
>>>>> down technically. Denying global warming, shutting off time signals,
>> and
>>>>> so on, is great stuff.
>>>>> On Saturday, August 11, 2018, 6:10:12 PM PDT, Bob kb8tq <
>>>> ***@n1k.org>
>>>>> wrote:
>>>>>
>>>>> Hi
>>>>>
>>>>> One would *guess* that stopping WWVB (and killing mom and pop’s
>> “atomic
>>>>> clocks”) would not be a reasonable thing to do.
>>>>> It gets a lot of voters mad. I doubt that very many voters (percentage
>>>>> wise) would notice WWV and WWVH going away ….
>>>>>
>>>>> Bob
>>>>>
>>>>>> On Aug 11, 2018, at 9:00 PM, jimlux <***@earthlink.net> wrote:
>>>>>>
>>>>>> On 8/10/18 12:45 PM, Robert LaJeunesse wrote:
>>>>>>> I'd say it does get more detailed, with the $49M in cuts described
>>>>> generally in groups here:
>>>>>>> https://www.nist.gov/director/fy-2019-presidential-budget-
>>>>> request-summary/fundamental-measurement-quantum-science-and
>>>>>>> One item: "-$6.3 million supporting fundamental measurement
>>>>> dissemination, including the shutdown of NIST radio stations in
>> Colorado
>>>>> and Hawaii"
>>>>>>
>>>>>> I wonder if that's WWVB, or WWV & WWVH
>>>>>>
>>>>>> _______________________________________________
>>>>>> time-nuts mailing list -- time-***@lists.febo.com
>>>>>> To unsubscribe, go to http://lists.febo.com/mailman/
>>>>> listinfo/time-nuts_lists.febo.com
>>>>>> and follow the instructions there.
>>>>>
>>>>>
>>>>> _______________________________________________
>>>>> time-nuts mailing list -- time-***@lists.febo.com
>>>>> To unsubscribe, go to http://lists.febo.com/mailman/
>>>>> listinfo/time-nuts_lists.febo.com
>>>>> and follow the instructions there.
>>>>>
>>>>> _______________________________________________
>>>>> time-nuts mailing list -- time-***@lists.febo.com
>>>>> To unsubscribe, go to http://lists.febo.com/mailman/
>>>>> listinfo/time-nuts_lists.febo.com
>>>>> and follow the instructions there.
>>>>>
>>>> _______________________________________________
>>>> time-nuts mailing list -- time-***@lists.febo.com
>>>> To unsubscribe, go to http://lists.febo.com/mailman/
>>>> listinfo/time-nuts_lists.febo.com
>>>> and follow the instructions there.
>>>>
>>> _______________________________________________
>>> time-nuts mailing list -- time-***@lists.febo.com
>>> To unsubscribe, go to
>>> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
>>> and follow the instructions there.
>>
>> --
>> Dr. Don Latham
>> PO Box 404, Frenchtown, MT, 59834
>> VOX: 406-626-4304
>>
>>
>> _______________________________________________
>> time-nuts mailing list -- time-***@lists.febo.com
>> To unsubscribe, go to
>> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
>> and follow the instructions there.
>>
>
>
> --
> Joe Dempster
> +1 908 413 2889 (mobile)
> --
> Joe Dempster
> +1 908 413 2889 (m)
> _______________________________________________
> time-nuts mailing list -- time-***@lists.febo.com
> To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> and follow the instructions there.
>
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D. Resor
2018-08-12 05:44:47 UTC
Permalink
I wonder if this will also have any effect on Time Service for Computers, Personal and Commercial. A lot of MS Windows products check for the correct time using time servers access from the internet. I'm sure this will also affect outdoor clock towers which also use this reference.

Am I mistaken or is WWV the reference for all things dealing with the "time service"?

Don Resor

-----Original Message-----
From: time-nuts <time-nuts-***@lists.febo.com> On Behalf Of Dana Whitlow
Sent: Saturday, August 11, 2018 7:49 PM
To: Discussion of precise time and frequency measurement <time-***@lists.febo.com>
Subject: Re: [time-nuts] NIST

I fear the worst. The line in the website simply stated something like "shutting down the transmitters in Colorado and Hawaii", which would seem to include the whole enchilada.

For the wall clocks, GPS should work well if people are willing to go to
battery-
backed AC power. But not so good for wristwatches, where the expectation is to run at uW power levels. I for one would be very irritated at having to take my watch off my wrist and put it on a charging stand every night. So if this shutdown comes to pass, I'll be looking for an inexpensive GPS-to-WWVB converter, or at least plans for building one.

Dana




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Craig Kirkpatrick
2018-08-12 15:40:35 UTC
Permalink
I agree with Bob that shutting down WWVB would not go over well with the voters but losing WWV and WWVH will mainly be noticed only by HAMs.

Dana, I’m puzzled by what you wrote. I have 8 clocks and 2 wristwatches that sync with WWVB. When band conditions are poor they miss a sync for a day but still they are good quartz clocks so the time readout is still OK. When the band conditions are good again they sync up once per day usually around 2am (according to the manual for my wristwatch). I can easily tell the sync status on all but 4 of my clocks and they sync successfully about 90% of the overnight times. My wristwatches are Citizen models that charge by solar which is nice since I have a perfectly in sync watch that never needs to be opened to change a battery.

I do like the idea of a GPS to WWVB timecode radio transmitter. I think that would sell well to folks on the fringe of coverage for WWVB such as Florida, Hawaii, and Alaska or other parts of the globe. I’ve found the real limitation to reception of WWVB is local 60kHz noise in the home. For instance if I have a fan running to cool things in my shack then my WWVB clocks will not sync successfully.

I hope Nick Sayer is reading this and getting the idea to make a GPS to WWVB timecode radio transmitter, clever gent that he is. :-)

Best Wishes,
Craig
KI7CRA

> On Aug 11, 2018, at 7:48 PM, Dana Whitlow <***@gmail.com> wrote:
>
> I fear the worst. The line in the website simply stated something like
> "shutting down
> the transmitters in Colorado and Hawaii", which would seem to include the
> whole
> enchilada.
>
> For the wall clocks, GPS should work well if people are willing to go to
> battery-
> backed AC power. But not so good for wristwatches, where the expectation
> is to
> run at uW power levels. I for one would be very irritated at having to
> take my watch
> off my wrist and put it on a charging stand every night. So if this
> shutdown comes
> to pass, I'll be looking for an inexpensive GPS-to-WWVB converter, or at
> least
> plans for building one.
>
> Dana
>
>
> On Sat, Aug 11, 2018 at 8:12 PM, Bob Albert via time-nuts <
> time-***@lists.febo.com> wrote:
>
>> With any luck, the current administration will successfully push the USA
>> down technically. Denying global warming, shutting off time signals, and
>> so on, is great stuff.
>> On Saturday, August 11, 2018, 6:10:12 PM PDT, Bob kb8tq <***@n1k.org>
>> wrote:
>>
>> Hi
>>
>> One would *guess* that stopping WWVB (and killing mom and pop’s “atomic
>> clocks”) would not be a reasonable thing to do.
>> It gets a lot of voters mad. I doubt that very many voters (percentage
>> wise) would notice WWV and WWVH going away ….
>>
>> Bob
>>
>>> On Aug 11, 2018, at 9:00 PM, jimlux <***@earthlink.net> wrote:
>>>
>>> On 8/10/18 12:45 PM, Robert LaJeunesse wrote:
>>>> I'd say it does get more detailed, with the $49M in cuts described
>> generally in groups here:
>>>> https://www.nist.gov/director/fy-2019-presidential-budget-
>> request-summary/fundamental-measurement-quantum-science-and
>>>> One item: "-$6.3 million supporting fundamental measurement
>> dissemination, including the shutdown of NIST radio stations in Colorado
>> and Hawaii"
>>>
>>> I wonder if that's WWVB, or WWV & WWVH
>>>
>>> _______________________________________________
>>> time-nuts mailing list -- time-***@lists.febo.com
>>> To unsubscribe, go to http://lists.febo.com/mailman/
>> listinfo/time-nuts_lists.febo.com
>>> and follow the instructions there.
>>
>>
>> _______________________________________________
>> time-nuts mailing list -- time-***@lists.febo.com
>> To unsubscribe, go to http://lists.febo.com/mailman/
>> listinfo/time-nuts_lists.febo.com
>> and follow the instructions there.
>>
>> _______________________________________________
>> time-nuts mailing list -- time-***@lists.febo.com
>> To unsubscribe, go to http://lists.febo.com/mailman/
>> listinfo/time-nuts_lists.febo.com
>> and follow the instructions there.
>>
> _______________________________________________
> time-nuts mailing list -- time-***@lists.febo.com
> To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> and follow the instructions there.


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David J Taylor via time-nuts
2018-08-13 09:06:14 UTC
Permalink
From: Craig Kirkpatrick

I do like the idea of a GPS to WWVB timecode radio transmitter. I think
that would sell well to folks on the fringe of coverage for WWVB such as
Florida, Hawaii, and Alaska or other parts of the globe. I’ve found the
real limitation to reception of WWVB is local 60kHz noise in the home. For
instance if I have a fan running to cool things in my shack then my WWVB
clocks will not sync successfully.

I hope Nick Sayer is reading this and getting the idea to make a GPS to WWVB
timecode radio transmitter, clever gent that he is. :-)

Best Wishes,
Craig
KI7CRA
===============================================

What would be very useful would be if the design could also emulate the UK
MSF transmissions at 60 kHz (simple on/off coding) and perhaps the DCF77
transmissions at 77.5 kHz.

One issue (at least with the UK 198 kHz transmitter) is the unobtainability
of spares such as the high-power valves, I understand. You're right that
many devices rely on these LF transmissions, but so do many FM radios rely
on analogue transmissions which are going, if not already partially gone, in
Europe.

Thanks,
David GM8ARV
--
SatSignal Software - Quality software written to your requirements
Web: http://www.satsignal.eu
Email: david-***@blueyonder.co.uk
Twitter: @gm8arv


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Dana Whitlow
2018-08-13 09:09:20 UTC
Permalink
Craig,

The original main reason for WWVB had nothing to do with syncing our
"atomic"
wristwatches and clocks. It was for keeping local frequency standards
honest, for
which continuous coverage throughout the day and night was desirable (if not
always achievable). But for that application, a one-shot daily sync was
not really
good enough (for most users). Stations that used WWVB for serious purposes
used
outdoor electrostatically-shielded loop antennas, usually up on the roof,
to get
enough signal enough of the time.

I'm curious about your fan-related interference. Fans of the kind used for
"cooling"
living space generally use induction motors, which per se have no mechanism
for
generating RFI. However, more modern fans sometimes have digital control
systems, which of course do include built-in RFI generators. I wonder
which variety
you're using.

My Casio watch (module 3405) seems to sync reliably at night if held in a
favorable
orientation through the exercise, but if worn on the wrist at random but
changing
orientation, it often misses. Fortunately mine seems to drift only about 1
sec per
month when "free running", so I now leave auto-sync turned off and just do
a single
forced sync every few weeks when I decide it's getting "too far off" based
on WWV.

Dana


On Sun, Aug 12, 2018 at 10:40 AM, Craig Kirkpatrick <***@comcast.net>
wrote:

> I agree with Bob that shutting down WWVB would not go over well with the
> voters but losing WWV and WWVH will mainly be noticed only by HAMs.
>
> Dana, I’m puzzled by what you wrote. I have 8 clocks and 2 wristwatches
> that sync with WWVB. When band conditions are poor they miss a sync for a
> day but still they are good quartz clocks so the time readout is still OK.
> When the band conditions are good again they sync up once per day usually
> around 2am (according to the manual for my wristwatch). I can easily tell
> the sync status on all but 4 of my clocks and they sync successfully about
> 90% of the overnight times. My wristwatches are Citizen models that charge
> by solar which is nice since I have a perfectly in sync watch that never
> needs to be opened to change a battery.
>
> I do like the idea of a GPS to WWVB timecode radio transmitter. I think
> that would sell well to folks on the fringe of coverage for WWVB such as
> Florida, Hawaii, and Alaska or other parts of the globe. I’ve found the
> real limitation to reception of WWVB is local 60kHz noise in the home. For
> instance if I have a fan running to cool things in my shack then my WWVB
> clocks will not sync successfully.
>
> I hope Nick Sayer is reading this and getting the idea to make a GPS to
> WWVB timecode radio transmitter, clever gent that he is. :-)
>
> Best Wishes,
> Craig
> KI7CRA
>
> > On Aug 11, 2018, at 7:48 PM, Dana Whitlow <***@gmail.com> wrote:
> >
> > I fear the worst. The line in the website simply stated something like
> > "shutting down
> > the transmitters in Colorado and Hawaii", which would seem to include the
> > whole
> > enchilada.
> >
> > For the wall clocks, GPS should work well if people are willing to go to
> > battery-
> > backed AC power. But not so good for wristwatches, where the expectation
> > is to
> > run at uW power levels. I for one would be very irritated at having to
> > take my watch
> > off my wrist and put it on a charging stand every night. So if this
> > shutdown comes
> > to pass, I'll be looking for an inexpensive GPS-to-WWVB converter, or at
> > least
> > plans for building one.
> >
> > Dana
> >
> >
> > On Sat, Aug 11, 2018 at 8:12 PM, Bob Albert via time-nuts <
> > time-***@lists.febo.com> wrote:
> >
> >> With any luck, the current administration will successfully push the USA
> >> down technically. Denying global warming, shutting off time signals,
> and
> >> so on, is great stuff.
> >> On Saturday, August 11, 2018, 6:10:12 PM PDT, Bob kb8tq <
> ***@n1k.org>
> >> wrote:
> >>
> >> Hi
> >>
> >> One would *guess* that stopping WWVB (and killing mom and pop’s “atomic
> >> clocks”) would not be a reasonable thing to do.
> >> It gets a lot of voters mad. I doubt that very many voters (percentage
> >> wise) would notice WWV and WWVH going away ….
> >>
> >> Bob
> >>
> >>> On Aug 11, 2018, at 9:00 PM, jimlux <***@earthlink.net> wrote:
> >>>
> >>> On 8/10/18 12:45 PM, Robert LaJeunesse wrote:
> >>>> I'd say it does get more detailed, with the $49M in cuts described
> >> generally in groups here:
> >>>> https://www.nist.gov/director/fy-2019-presidential-budget-
> >> request-summary/fundamental-measurement-quantum-science-and
> >>>> One item: "-$6.3 million supporting fundamental measurement
> >> dissemination, including the shutdown of NIST radio stations in Colorado
> >> and Hawaii"
> >>>
> >>> I wonder if that's WWVB, or WWV & WWVH
> >>>
> >>> _______________________________________________
> >>> time-nuts mailing list -- time-***@lists.febo.com
> >>> To unsubscribe, go to http://lists.febo.com/mailman/
> >> listinfo/time-nuts_lists.febo.com
> >>> and follow the instructions there.
> >>
> >>
> >> _______________________________________________
> >> time-nuts mailing list -- time-***@lists.febo.com
> >> To unsubscribe, go to http://lists.febo.com/mailman/
> >> listinfo/time-nuts_lists.febo.com
> >> and follow the instructions there.
> >>
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> >> and follow the instructions there.
> >>
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> > and follow the instructions there.
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>
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Mike Cook
2018-08-13 09:55:09 UTC
Permalink
> Le 13 août 2018 à 11:09, Dana Whitlow <***@gmail.com> a écrit :
>
> Craig,
>
> The original main reason for WWVB had nothing to do with syncing our
> "atomic"
> wristwatches and clocks. It was for keeping local frequency standards
> honest, for
> which continuous coverage throughout the day and night was desirable (if not
> always achievable). But for that application, a one-shot daily sync was
> not really
> good enough (for most users). Stations that used WWVB for serious purposes
> used
> outdoor electrostatically-shielded loop antennas, usually up on the roof,
> to get
> enough signal enough of the time.

This function of disseminating a frequency reference is not mentioned at all in the NIST request for information document, nor in Microsemi’s response.
I expect most calibration labs have their own 5071As but that is not quite the same as having a NIST traceability. My Certificate of Calibration from SRS for one of my PRS10 rubidium standards indicates:
« Stanford Research Systems, Inc. certifies that this instrument has been calibrated to manufacturer specifications and accuracy at an ambient temperature of 23° +/- using instruments and standards which are traceable to the National Institute of Standards and Technology. «
I expect the big labs send their instruments of to Boulder for calibration, but there must be some smaller outfits still phase locking off WWVB. We in Europe have MSF, DCF and TDF for which off air frequency references are /were available and which are probably still being used.
How would this frequency traceability work if WWVB/WWVH pass to a private enterprise?



>
>
> On Sun, Aug 12, 2018 at 10:40 AM, Craig Kirkpatrick <***@comcast.net>
> wrote:
>
>> I agree with Bob that shutting down WWVB would not go over well with the
>> voters but losing WWV and WWVH will mainly be noticed only by HAMs.
>>
>> Dana, I’m puzzled by what you wrote. I have 8 clocks and 2 wristwatches
>> that sync with WWVB. When band conditions are poor they miss a sync for a
>> day but still they are good quartz clocks so the time readout is still OK.
>> When the band conditions are good again they sync up once per day usually
>> around 2am (according to the manual for my wristwatch). I can easily tell
>> the sync status on all but 4 of my clocks and they sync successfully about
>> 90% of the overnight times. My wristwatches are Citizen models that charge
>> by solar which is nice since I have a perfectly in sync watch that never
>> needs to be opened to change a battery.
>>
>> I do like the idea of a GPS to WWVB timecode radio transmitter. I think
>> that would sell well to folks on the fringe of coverage for WWVB such as
>> Florida, Hawaii, and Alaska or other parts of the globe. I’ve found the
>> real limitation to reception of WWVB is local 60kHz noise in the home. For
>> instance if I have a fan running to cool things in my shack then my WWVB
>> clocks will not sync successfully.
>>
>> I hope Nick Sayer is reading this and getting the idea to make a GPS to
>> WWVB timecode radio transmitter, clever gent that he is. :-)
>>
>> Best Wishes,
>> Craig
>> KI7CRA
>>
>>> On Aug 11, 2018, at 7:48 PM, Dana Whitlow <***@gmail.com> wrote:
>>>
>>> I fear the worst. The line in the website simply stated something like
>>> "shutting down
>>> the transmitters in Colorado and Hawaii", which would seem to include the
>>> whole
>>> enchilada.
>>>
>>> For the wall clocks, GPS should work well if people are willing to go to
>>> battery-
>>> backed AC power. But not so good for wristwatches, where the expectation
>>> is to
>>> run at uW power levels. I for one would be very irritated at having to
>>> take my watch
>>> off my wrist and put it on a charging stand every night. So if this
>>> shutdown comes
>>> to pass, I'll be looking for an inexpensive GPS-to-WWVB converter, or at
>>> least
>>> plans for building one.
>>>
>>> Dana
>>>
>>>
>>> On Sat, Aug 11, 2018 at 8:12 PM, Bob Albert via time-nuts <
>>> time-***@lists.febo.com> wrote:
>>>
>>>> With any luck, the current administration will successfully push the USA
>>>> down technically. Denying global warming, shutting off time signals,
>> and
>>>> so on, is great stuff.
>>>> On Saturday, August 11, 2018, 6:10:12 PM PDT, Bob kb8tq <
>> ***@n1k.org>
>>>> wrote:
>>>>
>>>> Hi
>>>>
>>>> One would *guess* that stopping WWVB (and killing mom and pop’s “atomic
>>>> clocks”) would not be a reasonable thing to do.
>>>> It gets a lot of voters mad. I doubt that very many voters (percentage
>>>> wise) would notice WWV and WWVH going away ….
>>>>
>>>> Bob
>>>>
>>>>> On Aug 11, 2018, at 9:00 PM, jimlux <***@earthlink.net> wrote:
>>>>>
>>>>> On 8/10/18 12:45 PM, Robert LaJeunesse wrote:
>>>>>> I'd say it does get more detailed, with the $49M in cuts described
>>>> generally in groups here:
>>>>>> https://www.nist.gov/director/fy-2019-presidential-budget-
>>>> request-summary/fundamental-measurement-quantum-science-and
>>>>>> One item: "-$6.3 million supporting fundamental measurement
>>>> dissemination, including the shutdown of NIST radio stations in Colorado
>>>> and Hawaii"
>>>>>
>>>>> I wonder if that's WWVB, or WWV & WWVH
>>>>>
>>>>> _______________________________________________
>>>>> time-nuts mailing list -- time-***@lists.febo.com
>>>>> To unsubscribe, go to http://lists.febo.com/mailman/
>>>> listinfo/time-nuts_lists.febo.com
>>>>> and follow the instructions there.
>>>>
>>>>
>>>> _______________________________________________
>>>> time-nuts mailing list -- time-***@lists.febo.com
>>>> To unsubscribe, go to http://lists.febo.com/mailman/
>>>> listinfo/time-nuts_lists.febo.com
>>>> and follow the instructions there.
>>>>
>>>> _______________________________________________
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>>>> listinfo/time-nuts_lists.febo.com
>>>> and follow the instructions there.
>>>>
>>> _______________________________________________
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>>> and follow the instructions there.
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>>
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Don’t worry about how powerful the machines are. Worry about who the machines are giving power to.


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jimlux
2018-08-13 12:39:47 UTC
Permalink
On 8/12/18 8:40 AM, Craig Kirkpatrick wrote:
> I agree with Bob that shutting down WWVB would not go over well with the voters but losing WWV and WWVH will mainly be noticed only by HAMs.


WWV/WWVH also provides HF propagation forecasts, severe weather warnings
for mariners, etc., as well as being a propagation beacon.

I don't think HF communications is completely going away - it's unique
in not requiring any infrastructure to achieve world-wide communications
other than the two endpoints of the link.

It's probably a smaller population than radio amateurs, but there are
people who work with HF propagation on a day to day basis. For example,
if Rocketlabs ever gets their act together and launches a couple more
rockets, I'll have a spacecraft in LEO for which I intend to use WWV and
WWVH as calibration sources.





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paul swed
2018-08-13 12:55:19 UTC
Permalink
Hello to the group. The Chronverter is now available again. US $37.
Its from unusual electronics as was mentioned earlier in the thread.
No matter how 2019 actually goes its a good way to keep the wwvb clocks
going.
Saves me from having to create the same thing.
Regards
Paul
WB8TSL

On Mon, Aug 13, 2018 at 8:39 AM, jimlux <***@earthlink.net> wrote:

> On 8/12/18 8:40 AM, Craig Kirkpatrick wrote:
>
>> I agree with Bob that shutting down WWVB would not go over well with the
>> voters but losing WWV and WWVH will mainly be noticed only by HAMs.
>>
>
>
> WWV/WWVH also provides HF propagation forecasts, severe weather warnings
> for mariners, etc., as well as being a propagation beacon.
>
> I don't think HF communications is completely going away - it's unique in
> not requiring any infrastructure to achieve world-wide communications other
> than the two endpoints of the link.
>
> It's probably a smaller population than radio amateurs, but there are
> people who work with HF propagation on a day to day basis. For example, if
> Rocketlabs ever gets their act together and launches a couple more rockets,
> I'll have a spacecraft in LEO for which I intend to use WWV and WWVH as
> calibration sources.
>
>
>
>
>
>
> _______________________________________________
> time-nuts mailing list -- time-***@lists.febo.com
> To unsubscribe, go to http://lists.febo.com/mailman/
> listinfo/time-nuts_lists.febo.com
> and follow the instructions there.
>
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Bob kb8tq
2018-08-13 13:10:31 UTC
Permalink
Hi

Ok, this is Time Nuts. We probably have a pretty good sample of those who use this and that as a source of time.
We also are reasonably conscious about what we are doing. NIST’s claimed reason for running WWV (and WWVH) is to
distribute accurate time and frequency.

Would / does anybody on the list actually use WWV as their *primary* source of accurate time or accurate frequency?

Ok, so how about as a secondary source of time?

Now show of hands …. third tier backup?

I’ll place my votes first …. rarely as a third tier backup. Why? It’s just not good enough any more compared to the other
things I have easily available.

No, I”m not debating how badly we need third or eight tier backups. The question is purely - what is it actually used for?

Bob

> On Aug 13, 2018, at 8:39 AM, jimlux <***@earthlink.net> wrote:
>
> On 8/12/18 8:40 AM, Craig Kirkpatrick wrote:
>> I agree with Bob that shutting down WWVB would not go over well with the voters but losing WWV and WWVH will mainly be noticed only by HAMs.
>
>
> WWV/WWVH also provides HF propagation forecasts, severe weather warnings for mariners, etc., as well as being a propagation beacon.
>
> I don't think HF communications is completely going away - it's unique in not requiring any infrastructure to achieve world-wide communications other than the two endpoints of the link.
>
> It's probably a smaller population than radio amateurs, but there are people who work with HF propagation on a day to day basis. For example, if Rocketlabs ever gets their act together and launches a couple more rockets, I'll have a spacecraft in LEO for which I intend to use WWV and WWVH as calibration sources.
>
>
>
>
>
> _______________________________________________
> time-nuts mailing list -- time-***@lists.febo.com
> To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> and follow the instructions there.


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Mark Spencer
2018-08-13 13:43:14 UTC
Permalink
I'll just add:

I got into time nuts after I acquired a GPSDO for checking the frequency accuracy of my amateur radios. I realized I needed a GPSDO when I couldn't figure out if I was seeing drift in my radios frequency standards or Doppler shift from WWV transmissions while using WWV as a frequency reference.

To recap a prior post I do use WWV fairly often as a time source (mostly when I am in "the field") and I have occasionally used WWV as a frequency standard (not withstanding my concerns about Doppler shift.) All of this is for non commercial / hobby use.



Mark Spencer

Aligned Solutions Co.
***@alignedsolutions.com
604 762 4099

> On Aug 13, 2018, at 2:10 PM, Bob kb8tq <***@n1k.org> wrote:
>
> Hi
>
> Ok, this is Time Nuts. We probably have a pretty good sample of those who use this and that as a source of time.
> We also are reasonably conscious about what we are doing. NIST’s claimed reason for running WWV (and WWVH) is to
> distribute accurate time and frequency.
>
> Would / does anybody on the list actually use WWV as their *primary* source of accurate time or accurate frequency?
>
> Ok, so how about as a secondary source of time?
>
> Now show of hands …. third tier backup?
>
> I’ll place my votes first …. rarely as a third tier backup. Why? It’s just not good enough any more compared to the other
> things I have easily available.
>
> No, I”m not debating how badly we need third or eight tier backups. The question is purely - what is it actually used for?
>
> Bob
>
>> On Aug 13, 2018, at 8:39 AM, jimlux <***@earthlink.net> wrote:
>>
>> On 8/12/18 8:40 AM, Craig Kirkpatrick wrote:
>>> I agree with Bob that shutting down WWVB would not go over well with the voters but losing WWV and WWVH will mainly be noticed only by HAMs.
>>
>>
>> WWV/WWVH also provides HF propagation forecasts, severe weather warnings for mariners, etc., as well as being a propagation beacon.
>>
>> I don't think HF communications is completely going away - it's unique in not requiring any infrastructure to achieve world-wide communications other than the two endpoints of the link.
>>
>> It's probably a smaller population than radio amateurs, but there are people who work with HF propagation on a day to day basis. For example, if Rocketlabs ever gets their act together and launches a couple more rockets, I'll have a spacecraft in LEO for which I intend to use WWV and WWVH as calibration sources.
>>
>>
>>
>>
>>
>> _______________________________________________
>> time-nuts mailing list -- time-***@lists.febo.com
>> To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
>> and follow the instructions there.
>
>
> _______________________________________________
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and fol
jimlux
2018-08-13 15:04:25 UTC
Permalink
On 8/13/18 6:10 AM, Bob kb8tq wrote:
> Hi
>
> Ok, this is Time Nuts. We probably have a pretty good sample of those who use this and that as a source of time.
> We also are reasonably conscious about what we are doing. NIST’s claimed reason for running WWV (and WWVH) is to
> distribute accurate time and frequency.
>
> Would / does anybody on the list actually use WWV as their *primary* source of accurate time or accurate frequency?
>

I don't use WWV (or WWVH) as a source of time/frequency per-se - what I
use it for is as a beacon at a known power, frequency, and antenna
pattern, with (presumably) very good close in phase noise.

The ionosphere has a coherence time of a few seconds, so ADEV of the
source at tau of 10 sec or longer isn't a huge thing for me. But that 1
Hz/1 sec time frame is of real interest.

As the receiver flies over, we get nice soundings "through" the
ionosphere with good performance in the short term.

The usual ionosondes don't have anywhere near the same carrier purity,
and, because they sweep, you have to have good time synchronization of
your super het receiver to make sure you can tune the signal.

With WWV, I can set my center frequency to, say, 10.005 MHz, record 25
kHz BW for several minutes as I fly over and make my measurements. The
"phase noise and ADEV" of my receiver position is very small - zipping
along 500 km at the top of the ionosphere, there's not a lot of bumps in
the road, so it's easy to model the position.

Not for my current spacecraft, but for a future one (SunRISE), we'll be
measuring (post processed) spacecraft position and time to a few ns.
The current one isn't that good - but for this one, we're interested in
the lumps and bumps of the ionosphere, and that's a "over time spans of
<3 seconds" kind of measurement.


That said, if WWV were to turn off tomorrow, I could probably build a
ground beacon with adequate performance to do my science. I don't need
kilowatts of radiated power - it's just convenient that WWV exists and
someone else does it. And in reality, I'd rather have an antenna which
radiates more "up" than "out" - WWV and WWVH are vertical dipoles - good
for skywave propagation, not so hot for vertical sounding.





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Peter Laws
2018-08-13 13:52:44 UTC
Permalink
On Mon, Aug 13, 2018 at 8:10 AM, Bob kb8tq <***@n1k.org> wrote:
> Hi
>
> Ok, this is Time Nuts. We probably have a pretty good sample of those who use this and that as a source of time.
> We also are reasonably conscious about what we are doing. NIST’s claimed reason for running WWV (and WWVH) is to
> distribute accurate time and frequency.


> No, I”m not debating how badly we need third or eight tier backups. The question is purely - what is it actually used for?


I've never posted here and am mindful of the S/N ratio message sent
out this morning but I am glad to see a post like this.

I would be very sad if I could not tune to 10,000,000.000 000 Hz
(usually, but the others occasionally, too, though I haven't copied
the new/old 25-MHz beacon yet) and hear the reassuring beat of WWV.
Given all the garbage on most of the radio bands, amateur or
professional, especially MW, WWV's programming is about the best out
there.

But I don't use them for time. Everything at work is NTP with three
Symmetricom (yep, just old enough) S100s disciplining a set of servers
that users aim at. Occasionally, someone fusses about "needing" PTP
for something or other "because it's better" until we start mentioning
the cost of the hardware and they suddenly decide that NTP is more
than enough. Yes, NTP relies on GPS (and I guess the other GNSSs
these days) for the most part but there are other sources of time out
there that are not GPS based. Dave Mills, W3HCF, included hooks for
WWV receivers in the NTP reference implementation on which most NTP
clients are based, but in all the years I've tinkered with NTP, I
don't ever remember seeing a Stratum 1 advertising that it's
disciplined by WWV.

Some buildings where I work have Primex master clock systems - GPS
receiver -> 72-MHz transmitter -> battery-powered wall clocks. Some
clocks don't get a good signal but that's more a function of who
positioned the master clock (not me!) than a fault with the system
itself.

WWV/WWVH/WWVB never enters into the picture anywhere on campus AFAIK.

As for voters suddenly marching on their Congressmen's office because
their WWVB-disciplined clock no longer keeps time let me ask this: if
WWVB stopped transmitting how many people who have "atomic clocks"
would 1) notice 2) understand that the atomic clock is actually
elsewhere, and 3) that the timecode is sent from a government radio
station on 60 kHz? Most would just say "ah, it's busted" and throw it
out.

I have yet to hear anyone make a case for retaining the HF system that
isn't backed by nostalgia.

As for solar flares taking out the various GNSSs ... wouldn't a solar
flare only take out the vehicles that were on the "sunny" side of the
Earth? Wouldn't the (approximately) half of the SVs that are in the
Earth's shadow be unaffected? Serious technical question - I have no
idea.

--
Peter Laws | N5UWY | plaws plaws net | Travel by Train!

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jimlux
2018-08-13 19:04:31 UTC
Permalink
On 8/13/18 6:52 AM, Peter Laws wrote:

>
> As for solar flares taking out the various GNSSs ... wouldn't a solar
> flare only take out the vehicles that were on the "sunny" side of the
> Earth? Wouldn't the (approximately) half of the SVs that are in the
> Earth's shadow be unaffected? Serious technical question - I have no
> idea.
>

Actually, it's the particles associated with the solar flare that cause
the problem, and they move substantially slower than the speed of light
(it takes hours to days), and they spread out a lot in time.

There's a plot at the wikipedia page on flares

https://en.wikipedia.org/wiki/Solar_flare#/media/File:ExtremeEvent_20120304-00h_20120317-24h.jpg

You can see the proton flux is spread out over many hours


(I'm project manager for constellation of satellites we're going to
fly to do radio interferometry imaging of the sun at HF for Coronal Mass
Ejections.. time tags are important to us)

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Dr. Geophysics
2018-08-14 10:31:51 UTC
Permalink
An interesting interaction between the near Earth CMEs and the geomagnetic
field leads to some complex results also. Googling Carrington Event will
give some interesting details. The geomagnetic and geoelectric field
monitoring at observatories of CME interaction and associated earth
electrical currents is fascinating.

Is there any numeric code that will model the Newtonian trajectory and CME
geometry given input velocity and mass parameters? These are CME velocity
and mass parameters estimated now and I’ve seen Goddard NASA laboratory
animations which show CME magnetohydrodynamics (?) combined with the
estimated interplanetary trajectories and CME topology and always wondered
if there was, for example, accessible MATLAB or python codes available to
create such estimates. The NASA animations are found on YouTube.


On Mon, Aug 13, 2018 at 15:05 jimlux <***@earthlink.net> wrote:

> On 8/13/18 6:52 AM, Peter Laws wrote:
>
> >
> > As for solar flares taking out the various GNSSs ... wouldn't a solar
> > flare only take out the vehicles that were on the "sunny" side of the
> > Earth? Wouldn't the (approximately) half of the SVs that are in the
> > Earth's shadow be unaffected? Serious technical question - I have no
> > idea.
> >
>
> Actually, it's the particles associated with the solar flare that cause
> the problem, and they move substantially slower than the speed of light
> (it takes hours to days), and they spread out a lot in time.
>
> There's a plot at the wikipedia page on flares
>
>
> https://en.wikipedia.org/wiki/Solar_flare#/media/File:ExtremeEvent_20120304-00h_20120317-24h.jpg
>
> You can see the proton flux is spread out over many hours
>
>
> (I'm project manager for constellation of satellites we're going to
> fly to do radio interferometry imaging of the sun at HF for Coronal Mass
> Ejections.. time tags are important to us)
>
> _______________________________________________
> time-nuts mailing list -- time-***@lists.febo.com
> To unsubscribe, go to
> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> and follow the instructions there.
>
--
Dr. Geophysics
http://dr.geophysics.googlepages.com
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Peter Laws
2018-08-30 16:58:04 UTC
Permalink
On Mon, Aug 13, 2018 at 8:52 AM Peter Laws <***@gmail.com> wrote:


> I have yet to hear anyone make a case for retaining the HF system that
> isn't backed by nostalgia.

Still looking for this. Most of the "OMG IF WWV GOES AWAY MILLIONS
WILL DIE" posts (elsewhere, not here ... quite ...) are the type of
hysteria that is usually reserved for, I don't know, the EMP folks.
:-)


> As for solar flares taking out the various GNSSs ... wouldn't a solar
> flare only take out the vehicles that were on the "sunny" side of the
> Earth? Wouldn't the (approximately) half of the SVs that are in the
> Earth's shadow be unaffected? Serious technical question - I have no
> idea.

One of the responses to my initial message pointed out that the
effects of solar flares and CMEs take a while to get from Sol to Sol
III and don't arrive all at once, so potentially all GNSS spacecraft
could be affected.

Since then, I've been poking around for papers on the effect
(observed, potential, theoretical) of these events on the Navstar or
other GNSS constellations but am not having much luck. I assume it's
because I'm not putting the right magic incantation into the google
machine.

Anyone got some cites? Looking for the effect of solar flares and
CMEs on the spacecraft themselves and not how the GNSSs can be used to
measure the effects on the ionosphere, etc (those seem plentiful).
IOW, I'm curious about the resiliency of the systems to solar events.

I did note that at the time of the 1989 solar event that took out a
lot of Hydro Quebec's grid, only the "Block I" experimental GPS "SVs"
were in orbit. Well, maybe a couple of the later ones - the
operational constellation started launching about a month before that
flare.

As I said initially, I'll be sad if WWV* goes away but it won't affect
my life in any measurable way that I can see. I mean, other than the
mantle clock slowly losing time.

--
Peter Laws | N5UWY | plaws plaws net | Travel by Train!

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Bob kb8tq
2018-08-30 17:57:51 UTC
Permalink
Hi

> On Aug 30, 2018, at 12:58 PM, Peter Laws <***@gmail.com> wrote:
>
> On Mon, Aug 13, 2018 at 8:52 AM Peter Laws <***@gmail.com> wrote:
>
>
>> I have yet to hear anyone make a case for retaining the HF system that
>> isn't backed by nostalgia.
>
> Still looking for this. Most of the "OMG IF WWV GOES AWAY MILLIONS
> WILL DIE" posts (elsewhere, not here ... quite ...) are the type of
> hysteria that is usually reserved for, I don't know, the EMP folks.
> :-)
>
>
>> As for solar flares taking out the various GNSSs ... wouldn't a solar
>> flare only take out the vehicles that were on the "sunny" side of the
>> Earth? Wouldn't the (approximately) half of the SVs that are in the
>> Earth's shadow be unaffected? Serious technical question - I have no
>> idea.
>
> One of the responses to my initial message pointed out that the
> effects of solar flares and CMEs take a while to get from Sol to Sol
> III and don't arrive all at once, so potentially all GNSS spacecraft
> could be affected.
>
> Since then, I've been poking around for papers on the effect
> (observed, potential, theoretical) of these events on the Navstar or
> other GNSS constellations but am not having much luck. I assume it's
> because I'm not putting the right magic incantation into the google
> machine.
>
> Anyone got some cites? Looking for the effect of solar flares and
> CMEs on the spacecraft themselves and not how the GNSSs can be used to
> measure the effects on the ionosphere, etc (those seem plentiful).
> IOW, I'm curious about the resiliency of the systems to solar events.
>
> I did note that at the time of the 1989 solar event that took out a
> lot of Hydro Quebec's grid, only the "Block I" experimental GPS "SVs"
> were in orbit. Well, maybe a couple of the later ones - the
> operational constellation started launching about a month before that
> flare.
>

There most certainly was a lot of “stuff” in orbit by that time. If there was
a mass die off of satellites, you would not have to look hard to find out about
it.

Bob

> As I said initially, I'll be sad if WWV* goes away but it won't affect
> my life in any measurable way that I can see. I mean, other than the
> mantle clock slowly losing time.
>
> --
> Peter Laws | N5UWY | plaws plaws net | Travel by Train!
>
> _______________________________________________
> time-nuts mailing list -- time-***@lists.febo.com
> To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> and follow the instructions there.


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Peter Laws via time-nuts
2018-08-30 18:14:17 UTC
Permalink
On Thu, Aug 30, 2018 at 12:59 PM Bob kb8tq <***@n1k.org> wrote:

> There most certainly was a lot of “stuff” in orbit by that time. If there was
> a mass die off of satellites, you would not have to look hard to find out about
> it.

Probably not as many as there are 3 decades later, but of course.
Satellite service (any type of satellite) is much more likely to be
human-caued.

But here (and in other fora) the concern is that WWV Must Be
Maintained in order to save us from being late for coffee if another
event on the level of the Carrington Event takes out every single GNSS
spacecraft in orbit. But I can't find anything on the effect of that
sort of solar event on satellites. Almost as if, maybe, satellite
operators were aware of solar physics and planned for this sort of
event.

And I still haven't seen any coherent argument in favor of keeping WWV
that doesn't involve nostalgia or (perhaps) unfounded fear.

--
Peter Laws | N5UWY | plaws plaws net | Travel by Train!

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Bob kb8tq
2018-08-31 13:36:34 UTC
Permalink
Hi

“Backbone timing” gets done by boxes buried deep in systems. Those systems take years
to design. The boxes that go in them similarly take years to get onto the market. Once designed
deployment is far from instantaneous. Operators are always pressed by cost constraints. Adding
anything beyond the minimums … not going to happen.

The result is that there are no systems out there that use WWVB or WWV other than wrist watches
and wall clock like devices. Utilities (cell phones, internet, finance ) run with something else. Converting
them to a secondary “something” is a many years sort of thing, even if it is technically feasible.

You can pull a bunch of spare GPS sat’s out of storage and get them in orbit *way* quicker than you can
rebuild every cell tower in the country. In fact, newer designs run their timing in a way that a GPS failure
is not that big a deal. How long it’ll take before that sort of design is common in the US…. years and years …

If you are going to come up with a time source at the ~ 10 ns level, that’s not going to happen from WWVB
or WWV. They never were good enough to get to that level and it’s not on the transmit end. You would need
a very different system. It’s been a long time since any of these services (internet, finance, cell ) were in the
millisecond or even the microsecond range. The modern stuff in all theses areas is < 100 ns.

How long would it take to change all this? Well first some random Senior Member of the IEEE would
have to start writing papers about the various issues. Various organizations in various countries would
need to hold meeting after meeting after meeting talking things over. Somebody eventually would have
to come up with funds to actually try a few things. Maybe they work in the real world / maybe they don’t
work.

Once you prove you have a system that can do “good enough", you would need laws / regulations passed to
make the “new thing” part of the required designs. You also need funding bills to deploy the “source” end
of things and time to get that up and running. Once it’s running, you then give manufacturers some amount of time
to get it in the field ….. and extensions when that doesn’t happen. Twenty years? Thirty years? Maybe longer?
This stuff does not go very fast.

Best bet on what the “new thing” would be? Something like IEEE-1588 over fiber. It cuts out a bunch of this and
that in terms of experiments and testing the basic system. We know most of *how* to do it already. It’s just a matter
of a billions of dollars in tax money to get the gaps filled in and then a few tens of billions in tax money to get
the backbone gear in place. Once that’s done you ramp up to the really expensive part of the deal ….Is it paid
for by your tax return in April or by a higher price on every cell call / transaction you make? … who knows … it’s
a tax that you are paying either way.

Bob

> On Aug 30, 2018, at 2:14 PM, Peter Laws via time-nuts <time-***@lists.febo.com> wrote:
>
> On Thu, Aug 30, 2018 at 12:59 PM Bob kb8tq <***@n1k.org> wrote:
>
>> There most certainly was a lot of “stuff” in orbit by that time. If there was
>> a mass die off of satellites, you would not have to look hard to find out about
>> it.
>
> Probably not as many as there are 3 decades later, but of course.
> Satellite service (any type of satellite) is much more likely to be
> human-caued.
>
> But here (and in other fora) the concern is that WWV Must Be
> Maintained in order to save us from being late for coffee if another
> event on the level of the Carrington Event takes out every single GNSS
> spacecraft in orbit. But I can't find anything on the effect of that
> sort of solar event on satellites. Almost as if, maybe, satellite
> operators were aware of solar physics and planned for this sort of
> event.
>
> And I still haven't seen any coherent argument in favor of keeping WWV
> that doesn't involve nostalgia or (perhaps) unfounded fear.
>
> --
> Peter Laws | N5UWY | plaws plaws net | Travel by Train!
>
> _______________________________________________
> time-nuts mailing list -- time-***@lists.febo.com
> To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> and follow the instructions there.


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Magnus Danielson
2018-09-01 07:06:28 UTC
Permalink
On 08/31/2018 03:36 PM, Bob kb8tq wrote:
> Hi
>
> “Backbone timing” gets done by boxes buried deep in systems. Those systems take years
> to design. The boxes that go in them similarly take years to get onto the market. Once designed
> deployment is far from instantaneous. Operators are always pressed by cost constraints. Adding
> anything beyond the minimums … not going to happen.
>
> The result is that there are no systems out there that use WWVB or WWV other than wrist watches
> and wall clock like devices. Utilities (cell phones, internet, finance ) run with something else. Converting
> them to a secondary “something” is a many years sort of thing, even if it is technically feasible.
>
> You can pull a bunch of spare GPS sat’s out of storage and get them in orbit *way* quicker than you can
> rebuild every cell tower in the country. In fact, newer designs run their timing in a way that a GPS failure
> is not that big a deal. How long it’ll take before that sort of design is common in the US…. years and years …
>
> If you are going to come up with a time source at the ~ 10 ns level, that’s not going to happen from WWVB
> or WWV. They never were good enough to get to that level and it’s not on the transmit end. You would need
> a very different system. It’s been a long time since any of these services (internet, finance, cell ) were in the
> millisecond or even the microsecond range. The modern stuff in all theses areas is < 100 ns.

The actual requirements is usually on the 1-10 us level, but they are
happy when they have the extra precision.

> How long would it take to change all this? Well first some random Senior Member of the IEEE would
> have to start writing papers about the various issues. Various organizations in various countries would
> need to hold meeting after meeting after meeting talking things over. Somebody eventually would have
> to come up with funds to actually try a few things. Maybe they work in the real world / maybe they don’t
> work.
>
> Once you prove you have a system that can do “good enough", you would need laws / regulations passed to
> make the “new thing” part of the required designs. You also need funding bills to deploy the “source” end
> of things and time to get that up and running. Once it’s running, you then give manufacturers some amount of time
> to get it in the field ….. and extensions when that doesn’t happen. Twenty years? Thirty years? Maybe longer?
> This stuff does not go very fast.

It's been done for 10+ years now. Some 15+ countries have nation wide
networks that makes them GPS independent for some applications.
It has been a fun system to design and deploy.

Getting more precision isn't all that hard, it just takes more effort in
the details and hence money and time. If people need 100 ns or 10 ns
system time, it can be done.

> Best bet on what the “new thing” would be? Something like IEEE-1588 over fiber. It cuts out a bunch of this and
> that in terms of experiments and testing the basic system. We know most of *how* to do it already. It’s just a matter
> of a billions of dollars in tax money to get the gaps filled in and then a few tens of billions in tax money to get
> the backbone gear in place. Once that’s done you ramp up to the really expensive part of the deal ….Is it paid
> for by your tax return in April or by a higher price on every cell call / transaction you make? … who knows … it’s
> a tax that you are paying either way.

IEEE 1588 isn't working out at all for WAN, it's stuck in LAN
environment, which is the dirty little secret of the industry. There is
trials for dedicated wavelengths with using 1588 or it's extension White
Rabbit that works great, but in any form of production environment it's
a mess.

Network based precision timing takes a number of hurdles to handle. I've
done my fair bit of them.

Cheers,
Magnus

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Bob kb8tq
2018-09-01 12:21:46 UTC
Permalink
Hi

> On Sep 1, 2018, at 3:06 AM, Magnus Danielson <***@rubidium.dyndns.org> wrote:
>
>
>
> On 08/31/2018 03:36 PM, Bob kb8tq wrote:
>> Hi
>>
>> “Backbone timing” gets done by boxes buried deep in systems. Those systems take years
>> to design. The boxes that go in them similarly take years to get onto the market. Once designed
>> deployment is far from instantaneous. Operators are always pressed by cost constraints. Adding
>> anything beyond the minimums … not going to happen.
>>
>> The result is that there are no systems out there that use WWVB or WWV other than wrist watches
>> and wall clock like devices. Utilities (cell phones, internet, finance ) run with something else. Converting
>> them to a secondary “something” is a many years sort of thing, even if it is technically feasible.
>>
>> You can pull a bunch of spare GPS sat’s out of storage and get them in orbit *way* quicker than you can
>> rebuild every cell tower in the country. In fact, newer designs run their timing in a way that a GPS failure
>> is not that big a deal. How long it’ll take before that sort of design is common in the US…. years and years …
>>
>> If you are going to come up with a time source at the ~ 10 ns level, that’s not going to happen from WWVB
>> or WWV. They never were good enough to get to that level and it’s not on the transmit end. You would need
>> a very different system. It’s been a long time since any of these services (internet, finance, cell ) were in the
>> millisecond or even the microsecond range. The modern stuff in all theses areas is < 100 ns.
>
> The actual requirements is usually on the 1-10 us level, but they are
> happy when they have the extra precision.

Well, they are and they aren’t. The newer systems (which rapidly become the only system) are at the one microsecond
level after being in holder for many hours ( days?). The assumption is that only one tower (or chunk) goes into holdover
at a time and the rest are still at least 10X better than that. Cut them all loose an the numbers would have to be tighter.

In order to get them all at the 100 ns level, you need a source that is around 5 to 10X better than that. The timing source
is not the only source of error and you need to “train” your holdover clock with something that is mighty good. The
holdover spec often applies after a very short period of training (a day to several days). Indeed, if you put a Cs standard
in every cell tower and every internet node you probably could back off a bit on the 10X. With quartz or Rb, you need
the accuracy in training.

Bob



>
>> How long would it take to change all this? Well first some random Senior Member of the IEEE would
>> have to start writing papers about the various issues. Various organizations in various countries would
>> need to hold meeting after meeting after meeting talking things over. Somebody eventually would have
>> to come up with funds to actually try a few things. Maybe they work in the real world / maybe they don’t
>> work.
>>
>> Once you prove you have a system that can do “good enough", you would need laws / regulations passed to
>> make the “new thing” part of the required designs. You also need funding bills to deploy the “source” end
>> of things and time to get that up and running. Once it’s running, you then give manufacturers some amount of time
>> to get it in the field ….. and extensions when that doesn’t happen. Twenty years? Thirty years? Maybe longer?
>> This stuff does not go very fast.
>
> It's been done for 10+ years now. Some 15+ countries have nation wide
> networks that makes them GPS independent for some applications.
> It has been a fun system to design and deploy.
>
> Getting more precision isn't all that hard, it just takes more effort in
> the details and hence money and time. If people need 100 ns or 10 ns
> system time, it can be done.
>
>> Best bet on what the “new thing” would be? Something like IEEE-1588 over fiber. It cuts out a bunch of this and
>> that in terms of experiments and testing the basic system. We know most of *how* to do it already. It’s just a matter
>> of a billions of dollars in tax money to get the gaps filled in and then a few tens of billions in tax money to get
>> the backbone gear in place. Once that’s done you ramp up to the really expensive part of the deal ….Is it paid
>> for by your tax return in April or by a higher price on every cell call / transaction you make? … who knows … it’s
>> a tax that you are paying either way.
>
> IEEE 1588 isn't working out at all for WAN, it's stuck in LAN
> environment, which is the dirty little secret of the industry. There is
> trials for dedicated wavelengths with using 1588 or it's extension White
> Rabbit that works great, but in any form of production environment it's
> a mess.
>
> Network based precision timing takes a number of hurdles to handle. I've
> done my fair bit of them.
>
> Cheers,
> Magnus
>
> _______________________________________________
> time-nuts mailing list -- time-***@lists.febo.com
> To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> and follow the instructions there.


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Scott McGrath
2018-08-30 18:46:29 UTC
Permalink
The port of Long Beach CA was jammed wrt GPS for several months by a malfunctioning 29.95 TV preamplifier on a boat.

GPS was completely unusable when this unsuspecting guy was watching TV on his boat.

He had quite the surprise when the coasties with guns showed up.

The fact is civillian GPS Is trivial to jam and jammers can be bought ‘under the counter’ at any truckstop along with illlegal linear amplifiers.



On Aug 30, 2018, at 12:58 PM, Peter Laws <***@gmail.com> wrote:

On Mon, Aug 13, 2018 at 8:52 AM Peter Laws <***@gmail.com> wrote:


> I have yet to hear anyone make a case for retaining the HF system that
> isn't backed by nostalgia.

Still looking for this. Most of the "OMG IF WWV GOES AWAY MILLIONS
WILL DIE" posts (elsewhere, not here ... quite ...) are the type of
hysteria that is usually reserved for, I don't know, the EMP folks.
:-)


> As for solar flares taking out the various GNSSs ... wouldn't a solar
> flare only take out the vehicles that were on the "sunny" side of the
> Earth? Wouldn't the (approximately) half of the SVs that are in the
> Earth's shadow be unaffected? Serious technical question - I have no
> idea.

One of the responses to my initial message pointed out that the
effects of solar flares and CMEs take a while to get from Sol to Sol
III and don't arrive all at once, so potentially all GNSS spacecraft
could be affected.

Since then, I've been poking around for papers on the effect
(observed, potential, theoretical) of these events on the Navstar or
other GNSS constellations but am not having much luck. I assume it's
because I'm not putting the right magic incantation into the google
machine.

Anyone got some cites? Looking for the effect of solar flares and
CMEs on the spacecraft themselves and not how the GNSSs can be used to
measure the effects on the ionosphere, etc (those seem plentiful).
IOW, I'm curious about the resiliency of the systems to solar events.

I did note that at the time of the 1989 solar event that took out a
lot of Hydro Quebec's grid, only the "Block I" experimental GPS "SVs"
were in orbit. Well, maybe a couple of the later ones - the
operational constellation started launching about a month before that
flare.

As I said initially, I'll be sad if WWV* goes away but it won't affect
my life in any measurable way that I can see. I mean, other than the
mantle clock slowly losing time.

--
Peter Laws | N5UWY | plaws plaws net | Travel by Train!

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Bob kb8tq
2018-08-30 19:43:10 UTC
Permalink
Hi

When infastructure GPS *does* get jammed these days that source gets tracked down a lot faster
than a month or so. Anything that goes on for more than a day gets booted up pretty high
pretty fast. Indeed I’ve been in the middle of that more than I would have wished to be …..

The same sort of RFI issues that take out GPS from a TV preamp can equally well take out WWVB or WWV.
With WWVB, there are a *lot* of 60KHz switching power supplies out there to create problems. There is nothing
unique about any of these services in terms of being jam immune.

The bigger issue with any of them is spoofing. A proper GPSDO will go into holdover when RFI jammed. I would
*assume* the same would be true of a fancy WWVB device. I’m not at all sure that’s true of a real WWVB standard,
they haven’t been for sale new for a really long time. If your time source is in holdover, you can go out and track down
the issue. If it simply locks to the new signal …. not so much.

There is a subtle distinction in some of this. Newer systems do indeed want time. Older systems were generally after
frequency. The only WWVB standards I’ve seen were aimed at frequency (and frequency holdover) rather than time and
time holdover. Getting reasonable (1 to 10 ppb) frequency from WWVB is a very different task than getting the sort of time
that modern systems are after.

Bob

> On Aug 30, 2018, at 2:46 PM, Scott McGrath <***@gmail.com> wrote:
>
> The port of Long Beach CA was jammed wrt GPS for several months by a malfunctioning 29.95 TV preamplifier on a boat.
>
> GPS was completely unusable when this unsuspecting guy was watching TV on his boat.
>
> He had quite the surprise when the coasties with guns showed up.
>
> The fact is civillian GPS Is trivial to jam and jammers can be bought ‘under the counter’ at any truckstop along with illlegal linear amplifiers.
>
>
>
> On Aug 30, 2018, at 12:58 PM, Peter Laws <***@gmail.com> wrote:
>
> On Mon, Aug 13, 2018 at 8:52 AM Peter Laws <***@gmail.com> wrote:
>
>
>> I have yet to hear anyone make a case for retaining the HF system that
>> isn't backed by nostalgia.
>
> Still looking for this. Most of the "OMG IF WWV GOES AWAY MILLIONS
> WILL DIE" posts (elsewhere, not here ... quite ...) are the type of
> hysteria that is usually reserved for, I don't know, the EMP folks.
> :-)
>
>
>> As for solar flares taking out the various GNSSs ... wouldn't a solar
>> flare only take out the vehicles that were on the "sunny" side of the
>> Earth? Wouldn't the (approximately) half of the SVs that are in the
>> Earth's shadow be unaffected? Serious technical question - I have no
>> idea.
>
> One of the responses to my initial message pointed out that the
> effects of solar flares and CMEs take a while to get from Sol to Sol
> III and don't arrive all at once, so potentially all GNSS spacecraft
> could be affected.
>
> Since then, I've been poking around for papers on the effect
> (observed, potential, theoretical) of these events on the Navstar or
> other GNSS constellations but am not having much luck. I assume it's
> because I'm not putting the right magic incantation into the google
> machine.
>
> Anyone got some cites? Looking for the effect of solar flares and
> CMEs on the spacecraft themselves and not how the GNSSs can be used to
> measure the effects on the ionosphere, etc (those seem plentiful).
> IOW, I'm curious about the resiliency of the systems to solar events.
>
> I did note that at the time of the 1989 solar event that took out a
> lot of Hydro Quebec's grid, only the "Block I" experimental GPS "SVs"
> were in orbit. Well, maybe a couple of the later ones - the
> operational constellation started launching about a month before that
> flare.
>
> As I said initially, I'll be sad if WWV* goes away but it won't affect
> my life in any measurable way that I can see. I mean, other than the
> mantle clock slowly losing time.
>
> --
> Peter Laws | N5UWY | plaws plaws net | Travel by Train!
>
> _______________________________________________
> time-nuts mailing list -- time-***@lists.febo.com
> To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> and follow the instructions there.
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a
Brooke Clarke
2018-08-30 21:20:04 UTC
Permalink
Hi Bob:

I would disagree in that ease of jamming/spoofing is strongly related to wavelength.  That's because antenna efficiency
goes down as the size of the antenna gets smaller than 1/4 wave.
So, it's easy to make a GPS jammer (1,100 to 1,600MHz) since a 1/4 wavelength is a few inches, something that  you can
hold in your hand.
It's harder to make a WWV jammer (.5, 5, 10, 15, 20 MHz) since a 1/4 wavelength in in the range of  500 to 12 feet,
something that can be mounted on a vehicle for the higher frequencies.
But it's extremely hard to make a jammer for WWVB (60 kHz) where a 1/4wavelength is over 4,000 feet.  This means an
antenna that can be vehicle mounted will be very inefficient. Note this also means that it's extremely hard to make a
Loran-C jammer.  Note that the WWVB and LORAN-C transmitters run very high power and the antennas are massive.

This also means that if someone makes a WWVB simulator for their house the signal at the next door neighbor's house is
probably going to be too small to effect their clocks.

PS. Some decades ago I maintained a beacon transmitter "LAH" on 175 kHz where the rules for unlicensed operation limited
the input power to 1 Watt and total antenna length to 50 feet.  Under these conditions the effective radiated power
might be 2 milliwatts, orders of magnitude less if a portable system.
http://www.auroralchorus.com/pli/1750meter_antennas.pdf

--
Have Fun,

Brooke Clarke, N6GCE
https://www.PRC68.com
https://www.end2partygovernment.com/2012Issues.html
axioms:
1. The extent to which you can fix or improve something will be limited by how well you understand how it works.
2. Everybody, with no exceptions, holds false beliefs.

-------- Original Message --------
> Hi
>
> When infastructure GPS *does* get jammed these days that source gets tracked down a lot faster
> than a month or so. Anything that goes on for more than a day gets booted up pretty high
> pretty fast. Indeed I’ve been in the middle of that more than I would have wished to be …..
>
> The same sort of RFI issues that take out GPS from a TV preamp can equally well take out WWVB or WWV.
> With WWVB, there are a *lot* of 60KHz switching power supplies out there to create problems. There is nothing
> unique about any of these services in terms of being jam immune.
>
> The bigger issue with any of them is spoofing. A proper GPSDO will go into holdover when RFI jammed. I would
> *assume* the same would be true of a fancy WWVB device. I’m not at all sure that’s true of a real WWVB standard,
> they haven’t been for sale new for a really long time. If your time source is in holdover, you can go out and track down
> the issue. If it simply locks to the new signal …. not so much.
>
> There is a subtle distinction in some of this. Newer systems do indeed want time. Older systems were generally after
> frequency. The only WWVB standards I’ve seen were aimed at frequency (and frequency holdover) rather than time and
> time holdover. Getting reasonable (1 to 10 ppb) frequency from WWVB is a very different task than getting the sort of time
> that modern systems are after.
>
> Bob
>
>> On Aug 30, 2018, at 2:46 PM, Scott McGrath <***@gmail.com> wrote:
>>
>> The port of Long Beach CA was jammed wrt GPS for several months by a malfunctioning 29.95 TV preamplifier on a boat.
>>
>> GPS was completely unusable when this unsuspecting guy was watching TV on his boat.
>>
>> He had quite the surprise when the coasties with guns showed up.
>>
>> The fact is civillian GPS Is trivial to jam and jammers can be bought ‘under the counter’ at any truckstop along with illlegal linear amplifiers.
>>
>>
>>
>> On Aug 30, 2018, at 12:58 PM, Peter Laws <***@gmail.com> wrote:
>>
>> On Mon, Aug 13, 2018 at 8:52 AM Peter Laws <***@gmail.com> wrote:
>>
>>
>>> I have yet to hear anyone make a case for retaining the HF system that
>>> isn't backed by nostalgia.
>> Still looking for this. Most of the "OMG IF WWV GOES AWAY MILLIONS
>> WILL DIE" posts (elsewhere, not here ... quite ...) are the type of
>> hysteria that is usually reserved for, I don't know, the EMP folks.
>> :-)
>>
>>
>>> As for solar flares taking out the various GNSSs ... wouldn't a solar
>>> flare only take out the vehicles that were on the "sunny" side of the
>>> Earth? Wouldn't the (approximately) half of the SVs that are in the
>>> Earth's shadow be unaffected? Serious technical question - I have no
>>> idea.
>> One of the responses to my initial message pointed out that the
>> effects of solar flares and CMEs take a while to get from Sol to Sol
>> III and don't arrive all at once, so potentially all GNSS spacecraft
>> could be affected.
>>
>> Since then, I've been poking around for papers on the effect
>> (observed, potential, theoretical) of these events on the Navstar or
>> other GNSS constellations but am not having much luck. I assume it's
>> because I'm not putting the right magic incantation into the google
>> machine.
>>
>> Anyone got some cites? Looking for the effect of solar flares and
>> CMEs on the spacecraft themselves and not how the GNSSs can be used to
>> measure the effects on the ionosphere, etc (those seem plentiful).
>> IOW, I'm curious about the resiliency of the systems to solar events.
>>
>> I did note that at the time of the 1989 solar event that took out a
>> lot of Hydro Quebec's grid, only the "Block I" experimental GPS "SVs"
>> were in orbit. Well, maybe a couple of the later ones - the
>> operational constellation started launching about a month before that
>> flare.
>>
>> As I said initially, I'll be sad if WWV* goes away but it won't affect
>> my life in any measurable way that I can see. I mean, other than the
>> mantle clock slowly losing time.
>>
>> --
>> Peter Laws | N5UWY | plaws plaws net | Travel by Train!
>>
>> _______________________________________________
>> time-nuts mailing list -- time-***@lists.febo.com
>> To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
>> and follow the instructions there.
>>
>> _______________________________________________
>> time-nuts mailing list -- time-***@lists.febo.com
>> To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
>> and follow the instructions there.
>
> _______________________________________________
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and
Bob kb8tq
2018-08-30 21:56:20 UTC
Permalink
Hi

Well, designing jammers on a public forum is an “interesting” thing to do…..

With WWVB, you are fine with a “near field” solution. You don’t need something that propagates for
miles and miles. The other thing you have in your favor is that coming up with a KW at 60 KHz is
quite easy. All those 60 KHz switchers we complain about … there’s your dirt cheap source of parts.

The next part of the “solution” is to feed your signal into the local power grid. Your switcher is happy
with a low impedance load. The power line looks fairly low impedance at 60 KHz. It goes the RF and
out and about it flows. Indeed it works pretty well over a good chunk of ground. At least as good as your
typical GPS jammer and no more expensive. Been there end done all that, though not for a WWVB jammer.

Bob

> On Aug 30, 2018, at 5:20 PM, Brooke Clarke <***@pacific.net> wrote:
>
> Hi Bob:
>
> I would disagree in that ease of jamming/spoofing is strongly related to wavelength. That's because antenna efficiency goes down as the size of the antenna gets smaller than 1/4 wave.
> So, it's easy to make a GPS jammer (1,100 to 1,600MHz) since a 1/4 wavelength is a few inches, something that you can hold in your hand.
> It's harder to make a WWV jammer (.5, 5, 10, 15, 20 MHz) since a 1/4 wavelength in in the range of 500 to 12 feet, something that can be mounted on a vehicle for the higher frequencies.
> But it's extremely hard to make a jammer for WWVB (60 kHz) where a 1/4wavelength is over 4,000 feet. This means an antenna that can be vehicle mounted will be very inefficient. Note this also means that it's extremely hard to make a Loran-C jammer. Note that the WWVB and LORAN-C transmitters run very high power and the antennas are massive.
>
> This also means that if someone makes a WWVB simulator for their house the signal at the next door neighbor's house is probably going to be too small to effect their clocks.
>
> PS. Some decades ago I maintained a beacon transmitter "LAH" on 175 kHz where the rules for unlicensed operation limited the input power to 1 Watt and total antenna length to 50 feet. Under these conditions the effective radiated power might be 2 milliwatts, orders of magnitude less if a portable system.
> http://www.auroralchorus.com/pli/1750meter_antennas.pdf
>
> --
> Have Fun,
>
> Brooke Clarke, N6GCE
> https://www.PRC68.com
> https://www.end2partygovernment.com/2012Issues.html
> axioms:
> 1. The extent to which you can fix or improve something will be limited by how well you understand how it works.
> 2. Everybody, with no exceptions, holds false beliefs.
>
> -------- Original Message --------
>> Hi
>>
>> When infastructure GPS *does* get jammed these days that source gets tracked down a lot faster
>> than a month or so. Anything that goes on for more than a day gets booted up pretty high
>> pretty fast. Indeed I’ve been in the middle of that more than I would have wished to be …..
>>
>> The same sort of RFI issues that take out GPS from a TV preamp can equally well take out WWVB or WWV.
>> With WWVB, there are a *lot* of 60KHz switching power supplies out there to create problems. There is nothing
>> unique about any of these services in terms of being jam immune.
>>
>> The bigger issue with any of them is spoofing. A proper GPSDO will go into holdover when RFI jammed. I would
>> *assume* the same would be true of a fancy WWVB device. I’m not at all sure that’s true of a real WWVB standard,
>> they haven’t been for sale new for a really long time. If your time source is in holdover, you can go out and track down
>> the issue. If it simply locks to the new signal …. not so much.
>>
>> There is a subtle distinction in some of this. Newer systems do indeed want time. Older systems were generally after
>> frequency. The only WWVB standards I’ve seen were aimed at frequency (and frequency holdover) rather than time and
>> time holdover. Getting reasonable (1 to 10 ppb) frequency from WWVB is a very different task than getting the sort of time
>> that modern systems are after.
>>
>> Bob
>>
>>> On Aug 30, 2018, at 2:46 PM, Scott McGrath <***@gmail.com> wrote:
>>>
>>> The port of Long Beach CA was jammed wrt GPS for several months by a malfunctioning 29.95 TV preamplifier on a boat.
>>>
>>> GPS was completely unusable when this unsuspecting guy was watching TV on his boat.
>>>
>>> He had quite the surprise when the coasties with guns showed up.
>>>
>>> The fact is civillian GPS Is trivial to jam and jammers can be bought ‘under the counter’ at any truckstop along with illlegal linear amplifiers.
>>>
>>>
>>>
>>> On Aug 30, 2018, at 12:58 PM, Peter Laws <***@gmail.com> wrote:
>>>
>>> On Mon, Aug 13, 2018 at 8:52 AM Peter Laws <***@gmail.com> wrote:
>>>
>>>
>>>> I have yet to hear anyone make a case for retaining the HF system that
>>>> isn't backed by nostalgia.
>>> Still looking for this. Most of the "OMG IF WWV GOES AWAY MILLIONS
>>> WILL DIE" posts (elsewhere, not here ... quite ...) are the type of
>>> hysteria that is usually reserved for, I don't know, the EMP folks.
>>> :-)
>>>
>>>
>>>> As for solar flares taking out the various GNSSs ... wouldn't a solar
>>>> flare only take out the vehicles that were on the "sunny" side of the
>>>> Earth? Wouldn't the (approximately) half of the SVs that are in the
>>>> Earth's shadow be unaffected? Serious technical question - I have no
>>>> idea.
>>> One of the responses to my initial message pointed out that the
>>> effects of solar flares and CMEs take a while to get from Sol to Sol
>>> III and don't arrive all at once, so potentially all GNSS spacecraft
>>> could be affected.
>>>
>>> Since then, I've been poking around for papers on the effect
>>> (observed, potential, theoretical) of these events on the Navstar or
>>> other GNSS constellations but am not having much luck. I assume it's
>>> because I'm not putting the right magic incantation into the google
>>> machine.
>>>
>>> Anyone got some cites? Looking for the effect of solar flares and
>>> CMEs on the spacecraft themselves and not how the GNSSs can be used to
>>> measure the effects on the ionosphere, etc (those seem plentiful).
>>> IOW, I'm curious about the resiliency of the systems to solar events.
>>>
>>> I did note that at the time of the 1989 solar event that took out a
>>> lot of Hydro Quebec's grid, only the "Block I" experimental GPS "SVs"
>>> were in orbit. Well, maybe a couple of the later ones - the
>>> operational constellation started launching about a month before that
>>> flare.
>>>
>>> As I said initially, I'll be sad if WWV* goes away but it won't affect
>>> my life in any measurable way that I can see. I mean, other than the
>>> mantle clock slowly losing time.
>>>
>>> --
>>> Peter Laws | N5UWY | plaws plaws net | Travel by Train!
>>>
>>> _______________________________________________
>>> time-nuts mailing list -- time-***@lists.febo.com
>>> To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
>>> and follow the instructions there.
>>>
>>> _______________________________________________
>>> time-nuts mailing list -- time-***@lists.febo.com
>>> To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
>>> and follow the instructions there.
>>
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>> and follow the instructions there.
>>
>>
>
>
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Poul-Henning Kamp
2018-08-30 22:18:12 UTC
Permalink
--------
In message <96e995c4-5ca2-af02-9738-***@pacific.net>, Brooke Clarke writes:

>But it's extremely hard to make a jammer for WWVB (60 kHz) [...]

You can do it city-scale with a 18-wheeler sized loop-antenna
and a good size diesel-generator.

However pedestrians will very likely note metalic items vibrating
as they pass the "mystery white truck".

Sweden were much more serious about it:

http://www.antus.org/RT02.html

Tl;drs:

They erected 9 200m tall Loran-C class antennas each driven by
a Loran-C transmitter with an advanced degree which could jam
Loran-C or Chayka.

They even mounted decoy parabolas on the towers them to hide their
true purpose.

The fact that all the transmitters were on the east coast does drop
a hint that swedens much touted neutrality had a bit of a slant.

--
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
***@FreeBSD.ORG | TCP/IP since RFC 956
FreeBSD committer | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.

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Scott McGrath
2018-08-30 22:51:56 UTC
Permalink
As Brooke notes while low frequency jammers are possible, practicality is another matter, All it takes to jam a city scale area is a box the size of a pack of cigarettes. Because the GPS signal is very, very weak.

As an intentional denial put a couple hundred on stray animals. Now track those jammers down.

I doubt if any agency owns enough DF equipment to find them all in a reasonable amount of time.

Thats why we need backup systems and each backup system will have less and less accuracy as it increases in robustness. The HF systems could provide adequate syncing for the Market example.



On Aug 30, 2018, at 6:18 PM, Poul-Henning Kamp <***@phk.freebsd.dk> wrote:

--------
In message <96e995c4-5ca2-af02-9738-***@pacific.net>, Brooke Clarke writes:

> But it's extremely hard to make a jammer for WWVB (60 kHz) [...]

You can do it city-scale with a 18-wheeler sized loop-antenna
and a good size diesel-generator.

However pedestrians will very likely note metalic items vibrating
as they pass the "mystery white truck".

Sweden were much more serious about it:

http://www.antus.org/RT02.html

Tl;drs:

They erected 9 200m tall Loran-C class antennas each driven by
a Loran-C transmitter with an advanced degree which could jam
Loran-C or Chayka.

They even mounted decoy parabolas on the towers them to hide their
true purpose.

The fact that all the transmitters were on the east coast does drop
a hint that swedens much touted neutrality had a bit of a slant.

--
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
***@FreeBSD.ORG | TCP/IP since RFC 956
FreeBSD committer | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.

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Bob kb8tq
2018-08-31 00:22:16 UTC
Permalink
Hi

Actually it’s pretty simple to track down that sort of jammer ….. and yes, the gear to do it
is out there in quantity.

Bob

> On Aug 30, 2018, at 6:51 PM, Scott McGrath <***@gmail.com> wrote:
>
> As Brooke notes while low frequency jammers are possible, practicality is another matter, All it takes to jam a city scale area is a box the size of a pack of cigarettes. Because the GPS signal is very, very weak.
>
> As an intentional denial put a couple hundred on stray animals. Now track those jammers down.
>
> I doubt if any agency owns enough DF equipment to find them all in a reasonable amount of time.
>
> Thats why we need backup systems and each backup system will have less and less accuracy as it increases in robustness. The HF systems could provide adequate syncing for the Market example.
>
>
>
> On Aug 30, 2018, at 6:18 PM, Poul-Henning Kamp <***@phk.freebsd.dk> wrote:
>
> --------
> In message <96e995c4-5ca2-af02-9738-***@pacific.net>, Brooke Clarke writes:
>
>> But it's extremely hard to make a jammer for WWVB (60 kHz) [...]
>
> You can do it city-scale with a 18-wheeler sized loop-antenna
> and a good size diesel-generator.
>
> However pedestrians will very likely note metalic items vibrating
> as they pass the "mystery white truck".
>
> Sweden were much more serious about it:
>
> http://www.antus.org/RT02.html
>
> Tl;drs:
>
> They erected 9 200m tall Loran-C class antennas each driven by
> a Loran-C transmitter with an advanced degree which could jam
> Loran-C or Chayka.
>
> They even mounted decoy parabolas on the towers them to hide their
> true purpose.
>
> The fact that all the transmitters were on the east coast does drop
> a hint that swedens much touted neutrality had a bit of a slant.
>
> --
> Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
> ***@FreeBSD.ORG | TCP/IP since RFC 956
> FreeBSD committer | BSD since 4.3-tahoe
> Never attribute to malice what can adequately be explained by incompetence.
>
> _______________________________________________
> time-nuts mailing list -- time-***@lists.febo.com
> To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> and follow the instructions there.
>
> _______________________________________________
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and
djl
2018-08-30 23:13:26 UTC
Permalink
Is there a translation of this anywhere?
Don


> Sweden were much more serious about it:
>
> http://www.antus.org/RT02.html
>
> Tl;drs:
>
> They erected 9 200m tall Loran-C class antennas each driven by
> a Loran-C transmitter with an advanced degree which could jam
> Loran-C or Chayka.
>
> They even mounted decoy parabolas on the towers them to hide their
> true purpose.
>
> The fact that all the transmitters were on the east coast does drop
> a hint that swedens much touted neutrality had a bit of a slant.

--
Dr. Don Latham
PO Box 404, Frenchtown, MT, 59834
VOX: 406-626-4304


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Ben Bradley
2018-08-31 00:54:01 UTC
Permalink
https://translate.google.com/translate?sl=auto&tl=en&js=y&prev=_t&hl=en&ie=UTF-8&u=http%3A%2F%2Fwww.antus.org%2FRT02.html&edit-text=
On Thu, Aug 30, 2018 at 7:14 PM djl <***@montana.com> wrote:
>
> Is there a translation of this anywhere?
> Don
>
>
> > Sweden were much more serious about it:
> >
> > http://www.antus.org/RT02.html
> >
> > Tl;drs:
> >
> > They erected 9 200m tall Loran-C class antennas each driven by
> > a Loran-C transmitter with an advanced degree which could jam
> > Loran-C or Chayka.
> >
> > They even mounted decoy parabolas on the towers them to hide their
> > true purpose.
> >
> > The fact that all the transmitters were on the east coast does drop
> > a hint that swedens much touted neutrality had a bit of a slant.
>
> --
> Dr. Don Latham
> PO Box 404, Frenchtown, MT, 59834
> VOX: 406-626-4304
>
>
> _______________________________________________
> time-nuts mailing list -- time-***@lists.febo.com
> To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> and follow the instructions there.

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Magnus Danielson
2018-09-01 06:38:23 UTC
Permalink
Hi,

On 08/31/2018 12:18 AM, Poul-Henning Kamp wrote:
> --------
> In message <96e995c4-5ca2-af02-9738-***@pacific.net>, Brooke Clarke writes:
>
>> But it's extremely hard to make a jammer for WWVB (60 kHz) [...]
>
> You can do it city-scale with a 18-wheeler sized loop-antenna
> and a good size diesel-generator.
>
> However pedestrians will very likely note metalic items vibrating
> as they pass the "mystery white truck".
>
> Sweden were much more serious about it:
>
> http://www.antus.org/RT02.html
>
> Tl;drs:
>
> They erected 9 200m tall Loran-C class antennas each driven by
> a Loran-C transmitter with an advanced degree which could jam
> Loran-C or Chayka.
>
> They even mounted decoy parabolas on the towers them to hide their
> true purpose.
>
> The fact that all the transmitters were on the east coast does drop
> a hint that swedens much touted neutrality had a bit of a slant.
>

The "On" switch of the network where in the air defenece bunker. It was
only marked with "På" (Swedish for On) with no further markings. It was
designed for when the soviet bombers comes, at least they should loose
their Chayka guidance.

I knew one of the folks that where boss over the system, was to his
funeral recently. He also worked hard to get the classified material and
make a public report out of it. Time to refresh your swedish, as I doubt
any translations exist in public.

Cheers,
Magnus

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Gregory Maxwell
2018-08-30 23:05:48 UTC
Permalink
On Thu, Aug 30, 2018 at 9:43 PM Brooke Clarke <***@pacific.net> wrote:
> I would disagree in that ease of jamming/spoofing is strongly related to wavelength. That's because antenna efficiency
> goes down as the size of the antenna gets smaller than 1/4 wave.
> So, it's easy to make a GPS jammer (1,100 to 1,600MHz) since a 1/4 wavelength is a few inches, something that you can
> hold in your hand.

However, the short wavelengths of GPS make beam forming a reasonable
countermeasure against jamming.

By having a small array of GPS antennas a receiver can digitally form
beams that both aim directly at the relevant satellites (so even
reducing intersatellite interference) while also steering a deep null
in the direction of the jammer. If the jammer is powerful enough to
overload the front-end then this won't help, but against a
non-targeted area denying jammer it should be fairly effective.

There are many papers on GNSS beamforming. ( e.g.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5134596/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5134483/ )

This kind of anti-jamming solution should even be pretty inexpensive
-- really no more than the cost of N receivers. Except that it is
specialized technology and thus very expensive. :)

Seeing some open source software implementing beam-forming was one of
the things I hoped to see result from the open hardware multi-band
GNSS receivers like the GNSS firehose project (
http://pmonta.com/blog/2017/05/05/gnss-firehose-update/ ) since once
you're going through the trouble of running three coherent receivers
for three bands, stacking three more of them and locking them to the
same clock doesn't seem like a big engineering challenge... and the
rest is just DSP work.

Even absent fancy beam forming, for GNSS timing with a surveyed
position except at high latitudes it should be possible to use a
relatively high gain antenna pointed straight up and by doing so blind
yourself to terrestrial jammers at a cost of fewer SVs being
available. But I've never tried it.

In an urban area I noticed my own GPSDOs losing signal multiple times
per week. Monitoring with an SDR showed what appeared to be jammers.

As others have noted intermittent jamming is pretty benign to a GPSDO.
Spoofing, OTOH, can trivially mess up the timing. It's my view that
if you need timing for a security critical purpose there isn't really
any GNSS based solution commercially available to the general public
right now, the best bet is a local atomic reference with a GPSDO used
to monitor and initially set it.

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Wes
2018-08-30 23:25:10 UTC
Permalink
Before retiring I did some field work on the Tomahawk AGR
(https://www.raytheon.com/capabilities/products/gps_anti-jam)

Wes  N7WS

 On 8/30/2018 4:05 PM, Gregory Maxwell wrote:
>
> However, the short wavelengths of GPS make beam forming a reasonable
> countermeasure against jamming.


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Bob kb8tq
2018-08-31 00:24:38 UTC
Permalink
Hi

Since timing receivers are actually going to prefer high angle sats, an antenna that rejects
close to the horizon is a pretty common thing. Enhancing that sort of rejection doesn’t take
a lot of effort.

Bob

> On Aug 30, 2018, at 7:05 PM, Gregory Maxwell <***@gmail.com> wrote:
>
> On Thu, Aug 30, 2018 at 9:43 PM Brooke Clarke <***@pacific.net> wrote:
>> I would disagree in that ease of jamming/spoofing is strongly related to wavelength. That's because antenna efficiency
>> goes down as the size of the antenna gets smaller than 1/4 wave.
>> So, it's easy to make a GPS jammer (1,100 to 1,600MHz) since a 1/4 wavelength is a few inches, something that you can
>> hold in your hand.
>
> However, the short wavelengths of GPS make beam forming a reasonable
> countermeasure against jamming.
>
> By having a small array of GPS antennas a receiver can digitally form
> beams that both aim directly at the relevant satellites (so even
> reducing intersatellite interference) while also steering a deep null
> in the direction of the jammer. If the jammer is powerful enough to
> overload the front-end then this won't help, but against a
> non-targeted area denying jammer it should be fairly effective.
>
> There are many papers on GNSS beamforming. ( e.g.
> https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5134596/
> https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5134483/ )
>
> This kind of anti-jamming solution should even be pretty inexpensive
> -- really no more than the cost of N receivers. Except that it is
> specialized technology and thus very expensive. :)
>
> Seeing some open source software implementing beam-forming was one of
> the things I hoped to see result from the open hardware multi-band
> GNSS receivers like the GNSS firehose project (
> http://pmonta.com/blog/2017/05/05/gnss-firehose-update/ ) since once
> you're going through the trouble of running three coherent receivers
> for three bands, stacking three more of them and locking them to the
> same clock doesn't seem like a big engineering challenge... and the
> rest is just DSP work.
>
> Even absent fancy beam forming, for GNSS timing with a surveyed
> position except at high latitudes it should be possible to use a
> relatively high gain antenna pointed straight up and by doing so blind
> yourself to terrestrial jammers at a cost of fewer SVs being
> available. But I've never tried it.
>
> In an urban area I noticed my own GPSDOs losing signal multiple times
> per week. Monitoring with an SDR showed what appeared to be jammers.
>
> As others have noted intermittent jamming is pretty benign to a GPSDO.
> Spoofing, OTOH, can trivially mess up the timing. It's my view that
> if you need timing for a security critical purpose there isn't really
> any GNSS based solution commercially available to the general public
> right now, the best bet is a local atomic reference with a GPSDO used
> to monitor and initially set it.
>
> _______________________________________________
> time-nuts mailing list -- time-***@lists.febo.com
> To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> and follow the instructions there.


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Scott McGrath
2018-08-31 00:43:39 UTC
Permalink
Just ask the NY Port authority how ‘easy’ knocking these jammers offline is. Usually done by vehicle to vehicle inspection with a SA.

And yes the day job all too frequently searching for and identifying interference sources.

One of the more interesting ones was a halogen leak detector wiping out WiFi at a manufacturing plant. So my opinions on interference location are informed by leading teams of people doing just that.

Content by Scott
Typos by Siri

On Aug 30, 2018, at 8:24 PM, Bob kb8tq <***@n1k.org> wrote:

Hi

Since timing receivers are actually going to prefer high angle sats, an antenna that rejects
close to the horizon is a pretty common thing. Enhancing that sort of rejection doesn’t take
a lot of effort.

Bob

> On Aug 30, 2018, at 7:05 PM, Gregory Maxwell <***@gmail.com> wrote:
>
> On Thu, Aug 30, 2018 at 9:43 PM Brooke Clarke <***@pacific.net> wrote:
>> I would disagree in that ease of jamming/spoofing is strongly related to wavelength. That's because antenna efficiency
>> goes down as the size of the antenna gets smaller than 1/4 wave.
>> So, it's easy to make a GPS jammer (1,100 to 1,600MHz) since a 1/4 wavelength is a few inches, something that you can
>> hold in your hand.
>
> However, the short wavelengths of GPS make beam forming a reasonable
> countermeasure against jamming.
>
> By having a small array of GPS antennas a receiver can digitally form
> beams that both aim directly at the relevant satellites (so even
> reducing intersatellite interference) while also steering a deep null
> in the direction of the jammer. If the jammer is powerful enough to
> overload the front-end then this won't help, but against a
> non-targeted area denying jammer it should be fairly effective.
>
> There are many papers on GNSS beamforming. ( e.g.
> https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5134596/
> https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5134483/ )
>
> This kind of anti-jamming solution should even be pretty inexpensive
> -- really no more than the cost of N receivers. Except that it is
> specialized technology and thus very expensive. :)
>
> Seeing some open source software implementing beam-forming was one of
> the things I hoped to see result from the open hardware multi-band
> GNSS receivers like the GNSS firehose project (
> http://pmonta.com/blog/2017/05/05/gnss-firehose-update/ ) since once
> you're going through the trouble of running three coherent receivers
> for three bands, stacking three more of them and locking them to the
> same clock doesn't seem like a big engineering challenge... and the
> rest is just DSP work.
>
> Even absent fancy beam forming, for GNSS timing with a surveyed
> position except at high latitudes it should be possible to use a
> relatively high gain antenna pointed straight up and by doing so blind
> yourself to terrestrial jammers at a cost of fewer SVs being
> available. But I've never tried it.
>
> In an urban area I noticed my own GPSDOs losing signal multiple times
> per week. Monitoring with an SDR showed what appeared to be jammers.
>
> As others have noted intermittent jamming is pretty benign to a GPSDO.
> Spoofing, OTOH, can trivially mess up the timing. It's my view that
> if you need timing for a security critical purpose there isn't really
> any GNSS based solution commercially available to the general public
> right now, the best bet is a local atomic reference with a GPSDO used
> to monitor and initially set it.
>
> _______________________________________________
> time-nuts mailing list -- time-***@lists.febo.com
> To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> and follow the instructions there.


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Bob kb8tq
2018-08-31 01:00:50 UTC
Permalink
Hi

….. ok, so you are dealing with city wide jammers that take out all of New York City on a daily basis?
Again, that was the original example tossed out. “A cigarette pack sized jammer that takes out an entire
city”. A jammer with that sort of range is an easy jammer to spot.

Somehow I find that a bit difficult to believe. What I’ve seen and gone after are *far* shorter range than
that magic device. A short rang mobile jammer aimed at an ankle bracelet takes out an infrastructure device
for minutes. That’s why those devices have holdover capabilities.

Indeed at the point they *do* start interfering with major systems over a wide range…. bigger gear gets brought in.
Jamming that actually takes utility systems down is very rare. No cell phone service anywhere in New York is
something that gets noticed pretty fast. It also fires up meetings that last quite literally for years …..

Bob

> On Aug 30, 2018, at 8:43 PM, Scott McGrath <***@gmail.com> wrote:
>
> Just ask the NY Port authority how ‘easy’ knocking these jammers offline is. Usually done by vehicle to vehicle inspection with a SA.
>
> And yes the day job all too frequently searching for and identifying interference sources.
>
> One of the more interesting ones was a halogen leak detector wiping out WiFi at a manufacturing plant. So my opinions on interference location are informed by leading teams of people doing just that.
>
> Content by Scott
> Typos by Siri
>
> On Aug 30, 2018, at 8:24 PM, Bob kb8tq <***@n1k.org> wrote:
>
> Hi
>
> Since timing receivers are actually going to prefer high angle sats, an antenna that rejects
> close to the horizon is a pretty common thing. Enhancing that sort of rejection doesn’t take
> a lot of effort.
>
> Bob
>
>> On Aug 30, 2018, at 7:05 PM, Gregory Maxwell <***@gmail.com> wrote:
>>
>> On Thu, Aug 30, 2018 at 9:43 PM Brooke Clarke <***@pacific.net> wrote:
>>> I would disagree in that ease of jamming/spoofing is strongly related to wavelength. That's because antenna efficiency
>>> goes down as the size of the antenna gets smaller than 1/4 wave.
>>> So, it's easy to make a GPS jammer (1,100 to 1,600MHz) since a 1/4 wavelength is a few inches, something that you can
>>> hold in your hand.
>>
>> However, the short wavelengths of GPS make beam forming a reasonable
>> countermeasure against jamming.
>>
>> By having a small array of GPS antennas a receiver can digitally form
>> beams that both aim directly at the relevant satellites (so even
>> reducing intersatellite interference) while also steering a deep null
>> in the direction of the jammer. If the jammer is powerful enough to
>> overload the front-end then this won't help, but against a
>> non-targeted area denying jammer it should be fairly effective.
>>
>> There are many papers on GNSS beamforming. ( e.g.
>> https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5134596/
>> https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5134483/ )
>>
>> This kind of anti-jamming solution should even be pretty inexpensive
>> -- really no more than the cost of N receivers. Except that it is
>> specialized technology and thus very expensive. :)
>>
>> Seeing some open source software implementing beam-forming was one of
>> the things I hoped to see result from the open hardware multi-band
>> GNSS receivers like the GNSS firehose project (
>> http://pmonta.com/blog/2017/05/05/gnss-firehose-update/ ) since once
>> you're going through the trouble of running three coherent receivers
>> for three bands, stacking three more of them and locking them to the
>> same clock doesn't seem like a big engineering challenge... and the
>> rest is just DSP work.
>>
>> Even absent fancy beam forming, for GNSS timing with a surveyed
>> position except at high latitudes it should be possible to use a
>> relatively high gain antenna pointed straight up and by doing so blind
>> yourself to terrestrial jammers at a cost of fewer SVs being
>> available. But I've never tried it.
>>
>> In an urban area I noticed my own GPSDOs losing signal multiple times
>> per week. Monitoring with an SDR showed what appeared to be jammers.
>>
>> As others have noted intermittent jamming is pretty benign to a GPSDO.
>> Spoofing, OTOH, can trivially mess up the timing. It's my view that
>> if you need timing for a security critical purpose there isn't really
>> any GNSS based solution commercially available to the general public
>> right now, the best bet is a local atomic reference with a GPSDO used
>> to monitor and initially set it.
>>
>> _______________________________________________
>> time-nuts mailing list -- time-***@lists.febo.com
>> To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
>> and follow the instructions there.
>
>
> _______________________________________________
> time-nuts mailing list -- time-***@lists.febo.com
> To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> and follow the instructions there.
>
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> and follow the instructions there.


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Brooke Clarke
2018-08-31 01:54:17 UTC
Permalink
Hi Gregory:

I wonder if anyone has tried using a small parabolic dish, like used for Free To Air satellite TV and aimed it at a GPS
satellite track or at a WAAS geostationary satellite using a feed antenna with reverse polarization from a normal GPS
antenna?
http://www.prc68.com/I/FTA.shtml

--
Have Fun,

Brooke Clarke
https://www.PRC68.com
https://www.end2partygovernment.com/2012Issues.html
axioms:
1. The extent to which you can fix or improve something will be limited by how well you understand how it works.
2. Everybody, with no exceptions, holds false beliefs.

-------- Original Message --------
> On Thu, Aug 30, 2018 at 9:43 PM Brooke Clarke <***@pacific.net> wrote:
>> I would disagree in that ease of jamming/spoofing is strongly related to wavelength. That's because antenna efficiency
>> goes down as the size of the antenna gets smaller than 1/4 wave.
>> So, it's easy to make a GPS jammer (1,100 to 1,600MHz) since a 1/4 wavelength is a few inches, something that you can
>> hold in your hand.
> However, the short wavelengths of GPS make beam forming a reasonable
> countermeasure against jamming.
>
> By having a small array of GPS antennas a receiver can digitally form
> beams that both aim directly at the relevant satellites (so even
> reducing intersatellite interference) while also steering a deep null
> in the direction of the jammer. If the jammer is powerful enough to
> overload the front-end then this won't help, but against a
> non-targeted area denying jammer it should be fairly effective.
>
> There are many papers on GNSS beamforming. ( e.g.
> https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5134596/
> https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5134483/ )
>
> This kind of anti-jamming solution should even be pretty inexpensive
> -- really no more than the cost of N receivers. Except that it is
> specialized technology and thus very expensive. :)
>
> Seeing some open source software implementing beam-forming was one of
> the things I hoped to see result from the open hardware multi-band
> GNSS receivers like the GNSS firehose project (
> http://pmonta.com/blog/2017/05/05/gnss-firehose-update/ ) since once
> you're going through the trouble of running three coherent receivers
> for three bands, stacking three more of them and locking them to the
> same clock doesn't seem like a big engineering challenge... and the
> rest is just DSP work.
>
> Even absent fancy beam forming, for GNSS timing with a surveyed
> position except at high latitudes it should be possible to use a
> relatively high gain antenna pointed straight up and by doing so blind
> yourself to terrestrial jammers at a cost of fewer SVs being
> available. But I've never tried it.
>
> In an urban area I noticed my own GPSDOs losing signal multiple times
> per week. Monitoring with an SDR showed what appeared to be jammers.
>
> As others have noted intermittent jamming is pretty benign to a GPSDO.
> Spoofing, OTOH, can trivially mess up the timing. It's my view that
> if you need timing for a security critical purpose there isn't really
> any GNSS based solution commercially available to the general public
> right now, the best bet is a local atomic reference with a GPSDO used
> to monitor and initially set it.
>
> _______________________________________________
> time-nuts mailing list -- time-***@lists.febo.com
> To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> and follow the instructions there.
>


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Bob kb8tq
2018-08-31 02:22:45 UTC
Permalink
Hi

The original “we cracked GPS” paper back in the 1980’s (that unlimitedly lead to the end of SA)
used a medium sized dish ( think of the good old C-band antennas) to pick out a single sat.

Bob

> On Aug 30, 2018, at 9:54 PM, Brooke Clarke <***@pacific.net> wrote:
>
> Hi Gregory:
>
> I wonder if anyone has tried using a small parabolic dish, like used for Free To Air satellite TV and aimed it at a GPS satellite track or at a WAAS geostationary satellite using a feed antenna with reverse polarization from a normal GPS antenna?
> http://www.prc68.com/I/FTA.shtml
>
> --
> Have Fun,
>
> Brooke Clarke
> https://www.PRC68.com
> https://www.end2partygovernment.com/2012Issues.html
> axioms:
> 1. The extent to which you can fix or improve something will be limited by how well you understand how it works.
> 2. Everybody, with no exceptions, holds false beliefs.
>
> -------- Original Message --------
>> On Thu, Aug 30, 2018 at 9:43 PM Brooke Clarke <***@pacific.net> wrote:
>>> I would disagree in that ease of jamming/spoofing is strongly related to wavelength. That's because antenna efficiency
>>> goes down as the size of the antenna gets smaller than 1/4 wave.
>>> So, it's easy to make a GPS jammer (1,100 to 1,600MHz) since a 1/4 wavelength is a few inches, something that you can
>>> hold in your hand.
>> However, the short wavelengths of GPS make beam forming a reasonable
>> countermeasure against jamming.
>>
>> By having a small array of GPS antennas a receiver can digitally form
>> beams that both aim directly at the relevant satellites (so even
>> reducing intersatellite interference) while also steering a deep null
>> in the direction of the jammer. If the jammer is powerful enough to
>> overload the front-end then this won't help, but against a
>> non-targeted area denying jammer it should be fairly effective.
>>
>> There are many papers on GNSS beamforming. ( e.g.
>> https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5134596/
>> https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5134483/ )
>>
>> This kind of anti-jamming solution should even be pretty inexpensive
>> -- really no more than the cost of N receivers. Except that it is
>> specialized technology and thus very expensive. :)
>>
>> Seeing some open source software implementing beam-forming was one of
>> the things I hoped to see result from the open hardware multi-band
>> GNSS receivers like the GNSS firehose project (
>> http://pmonta.com/blog/2017/05/05/gnss-firehose-update/ ) since once
>> you're going through the trouble of running three coherent receivers
>> for three bands, stacking three more of them and locking them to the
>> same clock doesn't seem like a big engineering challenge... and the
>> rest is just DSP work.
>>
>> Even absent fancy beam forming, for GNSS timing with a surveyed
>> position except at high latitudes it should be possible to use a
>> relatively high gain antenna pointed straight up and by doing so blind
>> yourself to terrestrial jammers at a cost of fewer SVs being
>> available. But I've never tried it.
>>
>> In an urban area I noticed my own GPSDOs losing signal multiple times
>> per week. Monitoring with an SDR showed what appeared to be jammers.
>>
>> As others have noted intermittent jamming is pretty benign to a GPSDO.
>> Spoofing, OTOH, can trivially mess up the timing. It's my view that
>> if you need timing for a security critical purpose there isn't really
>> any GNSS based solution commercially available to the general public
>> right now, the best bet is a local atomic reference with a GPSDO used
>> to monitor and initially set it.
>>
>> _______________________________________________
>> time-nuts mailing list -- time-***@lists.febo.com
>> To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
>> and follow the instructions there.
>>
>
>
> _______________________________________________
> time-nuts mailing list -- time-***@lists.febo.com
> To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> and follow the instructions there.


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Brooke Clarke
2018-08-31 17:07:40 UTC
Permalink
Hi Bob:

Do you have and info on that article that would allow me to read it?

--
Have Fun,

Brooke Clarke
https://www.PRC68.com
https://www.end2partygovernment.com/2012Issues.html
axioms:
1. The extent to which you can fix or improve something will be limited by how well you understand how it works.
2. Everybody, with no exceptions, holds false beliefs.

-------- Original Message --------
> Hi
>
> The original “we cracked GPS” paper back in the 1980’s (that unlimitedly lead to the end of SA)
> used a medium sized dish ( think of the good old C-band antennas) to pick out a single sat.
>
> Bob
>
>> On Aug 30, 2018, at 9:54 PM, Brooke Clarke <***@pacific.net> wrote:
>>
>> Hi Gregory:
>>
>> I wonder if anyone has tried using a small parabolic dish, like used for Free To Air satellite TV and aimed it at a GPS satellite track or at a WAAS geostationary satellite using a feed antenna with reverse polarization from a normal GPS antenna?
>> http://www.prc68.com/I/FTA.shtml
>>
>> --
>> Have Fun,
>>
>> Brooke Clarke
>> https://www.PRC68.com
>> https://www.end2partygovernment.com/2012Issues.html
>> axioms:
>> 1. The extent to which you can fix or improve something will be limited by how well you understand how it works.
>> 2. Everybody, with no exceptions, holds false beliefs.
>>
>> -------- Original Message --------
>>> On Thu, Aug 30, 2018 at 9:43 PM Brooke Clarke <***@pacific.net> wrote:
>>>> I would disagree in that ease of jamming/spoofing is strongly related to wavelength. That's because antenna efficiency
>>>> goes down as the size of the antenna gets smaller than 1/4 wave.
>>>> So, it's easy to make a GPS jammer (1,100 to 1,600MHz) since a 1/4 wavelength is a few inches, something that you can
>>>> hold in your hand.
>>> However, the short wavelengths of GPS make beam forming a reasonable
>>> countermeasure against jamming.
>>>
>>> By having a small array of GPS antennas a receiver can digitally form
>>> beams that both aim directly at the relevant satellites (so even
>>> reducing intersatellite interference) while also steering a deep null
>>> in the direction of the jammer. If the jammer is powerful enough to
>>> overload the front-end then this won't help, but against a
>>> non-targeted area denying jammer it should be fairly effective.
>>>
>>> There are many papers on GNSS beamforming. ( e.g.
>>> https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5134596/
>>> https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5134483/ )
>>>
>>> This kind of anti-jamming solution should even be pretty inexpensive
>>> -- really no more than the cost of N receivers. Except that it is
>>> specialized technology and thus very expensive. :)
>>>
>>> Seeing some open source software implementing beam-forming was one of
>>> the things I hoped to see result from the open hardware multi-band
>>> GNSS receivers like the GNSS firehose project (
>>> http://pmonta.com/blog/2017/05/05/gnss-firehose-update/ ) since once
>>> you're going through the trouble of running three coherent receivers
>>> for three bands, stacking three more of them and locking them to the
>>> same clock doesn't seem like a big engineering challenge... and the
>>> rest is just DSP work.
>>>
>>> Even absent fancy beam forming, for GNSS timing with a surveyed
>>> position except at high latitudes it should be possible to use a
>>> relatively high gain antenna pointed straight up and by doing so blind
>>> yourself to terrestrial jammers at a cost of fewer SVs being
>>> available. But I've never tried it.
>>>
>>> In an urban area I noticed my own GPSDOs losing signal multiple times
>>> per week. Monitoring with an SDR showed what appeared to be jammers.
>>>
>>> As others have noted intermittent jamming is pretty benign to a GPSDO.
>>> Spoofing, OTOH, can trivially mess up the timing. It's my view that
>>> if you need timing for a security critical purpose there isn't really
>>> any GNSS based solution commercially available to the general public
>>> right now, the best bet is a local atomic reference with a GPSDO used
>>> to monitor and initially set it.
>>>
>>> _______________________________________________
>>> time-nuts mailing list -- time-***@lists.febo.com
>>> To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
>>> and follow the instructions there.
>>>
>>
>> _______________________________________________
>> time-nuts mailing list -- time-***@lists.febo.com
>> To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
>> and follow the instructions there.
>
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Bob kb8tq
2018-08-31 17:17:33 UTC
Permalink
Hi

It’s back in the FCS archives. I don’t think it’s one of the ones you can hit without going through a
paywall. It was a fun paper to attend. The chatter in the room was “interesting” to say the least.

Bob

> On Aug 31, 2018, at 1:07 PM, Brooke Clarke <***@pacific.net> wrote:
>
> Hi Bob:
>
> Do you have and info on that article that would allow me to read it?
>
> --
> Have Fun,
>
> Brooke Clarke
> https://www.PRC68.com
> https://www.end2partygovernment.com/2012Issues.html
> axioms:
> 1. The extent to which you can fix or improve something will be limited by how well you understand how it works.
> 2. Everybody, with no exceptions, holds false beliefs.
>
> -------- Original Message --------
>> Hi
>>
>> The original “we cracked GPS” paper back in the 1980’s (that unlimitedly lead to the end of SA)
>> used a medium sized dish ( think of the good old C-band antennas) to pick out a single sat.
>>
>> Bob
>>
>>> On Aug 30, 2018, at 9:54 PM, Brooke Clarke <***@pacific.net> wrote:
>>>
>>> Hi Gregory:
>>>
>>> I wonder if anyone has tried using a small parabolic dish, like used for Free To Air satellite TV and aimed it at a GPS satellite track or at a WAAS geostationary satellite using a feed antenna with reverse polarization from a normal GPS antenna?
>>> http://www.prc68.com/I/FTA.shtml
>>>
>>> --
>>> Have Fun,
>>>
>>> Brooke Clarke
>>> https://www.PRC68.com
>>> https://www.end2partygovernment.com/2012Issues.html
>>> axioms:
>>> 1. The extent to which you can fix or improve something will be limited by how well you understand how it works.
>>> 2. Everybody, with no exceptions, holds false beliefs.
>>>
>>> -------- Original Message --------
>>>> On Thu, Aug 30, 2018 at 9:43 PM Brooke Clarke <***@pacific.net> wrote:
>>>>> I would disagree in that ease of jamming/spoofing is strongly related to wavelength. That's because antenna efficiency
>>>>> goes down as the size of the antenna gets smaller than 1/4 wave.
>>>>> So, it's easy to make a GPS jammer (1,100 to 1,600MHz) since a 1/4 wavelength is a few inches, something that you can
>>>>> hold in your hand.
>>>> However, the short wavelengths of GPS make beam forming a reasonable
>>>> countermeasure against jamming.
>>>>
>>>> By having a small array of GPS antennas a receiver can digitally form
>>>> beams that both aim directly at the relevant satellites (so even
>>>> reducing intersatellite interference) while also steering a deep null
>>>> in the direction of the jammer. If the jammer is powerful enough to
>>>> overload the front-end then this won't help, but against a
>>>> non-targeted area denying jammer it should be fairly effective.
>>>>
>>>> There are many papers on GNSS beamforming. ( e.g.
>>>> https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5134596/
>>>> https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5134483/ )
>>>>
>>>> This kind of anti-jamming solution should even be pretty inexpensive
>>>> -- really no more than the cost of N receivers. Except that it is
>>>> specialized technology and thus very expensive. :)
>>>>
>>>> Seeing some open source software implementing beam-forming was one of
>>>> the things I hoped to see result from the open hardware multi-band
>>>> GNSS receivers like the GNSS firehose project (
>>>> http://pmonta.com/blog/2017/05/05/gnss-firehose-update/ ) since once
>>>> you're going through the trouble of running three coherent receivers
>>>> for three bands, stacking three more of them and locking them to the
>>>> same clock doesn't seem like a big engineering challenge... and the
>>>> rest is just DSP work.
>>>>
>>>> Even absent fancy beam forming, for GNSS timing with a surveyed
>>>> position except at high latitudes it should be possible to use a
>>>> relatively high gain antenna pointed straight up and by doing so blind
>>>> yourself to terrestrial jammers at a cost of fewer SVs being
>>>> available. But I've never tried it.
>>>>
>>>> In an urban area I noticed my own GPSDOs losing signal multiple times
>>>> per week. Monitoring with an SDR showed what appeared to be jammers.
>>>>
>>>> As others have noted intermittent jamming is pretty benign to a GPSDO.
>>>> Spoofing, OTOH, can trivially mess up the timing. It's my view that
>>>> if you need timing for a security critical purpose there isn't really
>>>> any GNSS based solution commercially available to the general public
>>>> right now, the best bet is a local atomic reference with a GPSDO used
>>>> to monitor and initially set it.
>>>>
>>>> _______________________________________________
>>>> time-nuts mailing list -- time-***@lists.febo.com
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>>>> and follow the instructions there.
>>>>
>>>
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Attila Kinali
2018-08-31 14:54:41 UTC
Permalink
On Thu, 30 Aug 2018 18:54:17 -0700
Brooke Clarke <***@pacific.net> wrote:

> I wonder if anyone has tried using a small parabolic dish, like used for Free To Air satellite TV and aimed it at a GPS
> satellite track or at a WAAS geostationary satellite using a feed antenna with reverse polarization from a normal GPS
> antenna?

I have somewhere a paper (which i cannot find currently, sorry) that
used a dish trained at one of the EGNOS satellites and used it as the
only source for timing. IIRC the results were promising, but not
spectacular. The problem being that all the ionospheric and tropospheric
effects limited the performance, which also could not be averaged
over several satellites. Hence most people today focus on whole
constelation systems and try to get the best out of that, even under
multipath and jamming.

Attila Kinali

--
It is upon moral qualities that a society is ultimately founded. All
the prosperity and technological sophistication in the world is of no
use without that foundation.
-- Miss Matheson, The Diamond Age, Neal Stephenson

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Azelio Boriani
2018-08-31 16:00:55 UTC
Permalink
Maybe this one is equivalent?
<http://freqelec.com/gps_gnss/waas_for_telecom_2-07.pdf>
On Fri, Aug 31, 2018 at 4:55 PM Attila Kinali <***@kinali.ch> wrote:
>
> On Thu, 30 Aug 2018 18:54:17 -0700
> Brooke Clarke <***@pacific.net> wrote:
>
> > I wonder if anyone has tried using a small parabolic dish, like used for Free To Air satellite TV and aimed it at a GPS
> > satellite track or at a WAAS geostationary satellite using a feed antenna with reverse polarization from a normal GPS
> > antenna?
>
> I have somewhere a paper (which i cannot find currently, sorry) that
> used a dish trained at one of the EGNOS satellites and used it as the
> only source for timing. IIRC the results were promising, but not
> spectacular. The problem being that all the ionospheric and tropospheric
> effects limited the performance, which also could not be averaged
> over several satellites. Hence most people today focus on whole
> constelation systems and try to get the best out of that, even under
> multipath and jamming.
>
> Attila Kinali
>
> --
> It is upon moral qualities that a society is ultimately founded. All
> the prosperity and technological sophistication in the world is of no
> use without that foundation.
> -- Miss Matheson, The Diamond Age, Neal Stephenson
>
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Brooke Clarke
2018-08-31 17:31:48 UTC
Permalink
Hi Azelio:

Thanks for the link.
It's interesting that their setup (a Ku band satellite TV antenna and a standard GPS timing antenna) worked as well as
it did with reversed polarity.  Does anyone know of a source of reverse polarity GPS antennas and a GPS timing receiver
that also processes WAAS signals?

--
Have Fun,

Brooke Clarke
https://www.PRC68.com
https://www.end2partygovernment.com/2012Issues.html
axioms:
1. The extent to which you can fix or improve something will be limited by how well you understand how it works.
2. Everybody, with no exceptions, holds false beliefs.

-------- Original Message --------
> Maybe this one is equivalent?
> <http://freqelec.com/gps_gnss/waas_for_telecom_2-07.pdf>
> On Fri, Aug 31, 2018 at 4:55 PM Attila Kinali <***@kinali.ch> wrote:
>> On Thu, 30 Aug 2018 18:54:17 -0700
>> Brooke Clarke <***@pacific.net> wrote:
>>
>>> I wonder if anyone has tried using a small parabolic dish, like used for Free To Air satellite TV and aimed it at a GPS
>>> satellite track or at a WAAS geostationary satellite using a feed antenna with reverse polarization from a normal GPS
>>> antenna?
>> I have somewhere a paper (which i cannot find currently, sorry) that
>> used a dish trained at one of the EGNOS satellites and used it as the
>> only source for timing. IIRC the results were promising, but not
>> spectacular. The problem being that all the ionospheric and tropospheric
>> effects limited the performance, which also could not be averaged
>> over several satellites. Hence most people today focus on whole
>> constelation systems and try to get the best out of that, even under
>> multipath and jamming.
>>
>> Attila Kinali
>>
>> --
>> It is upon moral qualities that a society is ultimately founded. All
>> the prosperity and technological sophistication in the world is of no
>> use without that foundation.
>> -- Miss Matheson, The Diamond Age, Neal Stephenson
>>
>> _______________________________________________
>> time-nuts mailing list -- time-***@lists.febo.com
>> To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
>> and follow the instructions there.
> _______________________________________________
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>


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and follo
jimlux
2018-08-31 17:54:38 UTC
Permalink
On 8/31/18 10:31 AM, Brooke Clarke wrote:
> Hi Azelio:
>
> Thanks for the link.
> It's interesting that their setup (a Ku band satellite TV antenna and a
> standard GPS timing antenna) worked as well as it did with reversed
> polarity.  Does anyone know of a source of reverse polarity GPS antennas
> and a GPS timing receiver that also processes WAAS signals?
>
you could wind your own helix - it's pretty non critical.
or just use linear pol, and take the 3dB hit. I'll bet the EGNOS + small
dish has enough gain to make up for it. (but the gain of a dish that is
a few lambda across isn't huge)



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Attila Kinali
2018-08-31 14:55:12 UTC
Permalink
On Thu, 30 Aug 2018 23:05:48 +0000
Gregory Maxwell <***@gmail.com> wrote:


> Seeing some open source software implementing beam-forming was one of
> the things I hoped to see result from the open hardware multi-band
> GNSS receivers like the GNSS firehose project (
> http://pmonta.com/blog/2017/05/05/gnss-firehose-update/ ) since once
> you're going through the trouble of running three coherent receivers
> for three bands, stacking three more of them and locking them to the
> same clock doesn't seem like a big engineering challenge... and the
> rest is just DSP work.

"Just DSP work" is a tad bit more than you think. You are dealing
with sevaral 1Msps of data, even for a simple L1 C/A receiver.
If you are going multi-band-multi-GNSS you are usually in the 50MHz BW
at L1 and 80MHz BW at L2/L5 range, which means you are dealing with
something in the order of 100Msps of data per channel (either as
a single stream of sample or two streams of samples with half rate).
Then you add to it that you will need at least 4bit ADCs to get
somewhat jaming proof, probably even 10bit or more and suddenly
you are dealing with 200-400Mbyte/s data per antenna. Constantly.
To be able to do reasonable beam forming, you probably need a 4 by 4
grid at least, that makes 16 antennas which brings us into the
3Gbyte/s to 6Gbyte/s region. And that's just the raw _input_ datarate
you have to handle.... A modern GNSS receiver has something in the
order of 50-100 correlators per band, each of which needs to receive
the full data rate mentioned above. So inside the chip, the data rate
gets multiplied as well.

Now take into considerations that beside running the correlators,
after you phase shifted and weighted the inputs correctly, you
have to run some fancy algorithms (on the raw data) to figure
out what these phase shifts and weights are. For each satellite
you are tracking individually. All this toghether means you have
run some pretty heavy computation, that is very likely not going
to fit into an FPGA, so you need to build a custom ASIC.



> Even absent fancy beam forming, for GNSS timing with a surveyed
> position except at high latitudes it should be possible to use a
> relatively high gain antenna pointed straight up and by doing so blind
> yourself to terrestrial jammers at a cost of fewer SVs being
> available. But I've never tried it.

You still need the lower satellites to survey your position accurately.
Besides that you lose a lot of in terms of timing accuracy, if you
have only a limited number of satellites. So you cannot decrease the
lower elevation angles too much. Going below -10dB is probably not
agood idea. Also, going from ~10 birds in view down to ~5 means that
your PPS jitter just increased by a factor of 5 to 10.
(source: experiment i've done here some time ago)

Besides, a narrow band jammer trips up most of the commercial receivers
badly (adds a correlation peak where it does not belong).
And for that to be effective you only need to be 5-10dB above the noise
level. Which is pretty easy to achieve, even if you have very directive
antenna (the sidelobes are usually only 10-30dB down from the main lobe)

Fortunately, narrow band jammers are also pretty easy to mask, given
you have enough bits in your ADC.

> As others have noted intermittent jamming is pretty benign to a GPSDO.
> Spoofing, OTOH, can trivially mess up the timing. It's my view that
> if you need timing for a security critical purpose there isn't really
> any GNSS based solution commercially available to the general public
> right now, the best bet is a local atomic reference with a GPSDO used
> to monitor and initially set it.

There is a reason why Microsemi is building more 5071 these days than
ever before (rumors have it that they are are 3-4 devices per week).

Attila Kinali
--
It is upon moral qualities that a society is ultimately founded. All
the prosperity and technological sophistication in the world is of no
use without that foundation.
-- Miss Matheson, The Diamond Age, Neal Stephenson

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Scott McGrath
2018-08-31 15:14:22 UTC
Permalink
I/We track down things that jam weather radars. Mostly WiFi access points misconfigured.

Which share many of the characteristics of GPS jammers

1 - small low powered
2 - one can ruin a pilots entire day
3 - distributed
4 - can literally be anywhere

Stuff like this is why FCC blocked anyone but chip manufacturers from updating WiFi radio firmware.

The overwhelming majority of the mods were attempts to improve performance. But the firmware hackers were unaware of the band sharing and also did not understand that signal characteristics need to be closely controlled and the limits the FCC applies are not there to ‘ruin my performance’ but to allow others to play nicely in that sandbox.

So many things in life should have been learned in kindergarten. Sadly many have forgotten those lessons.

On Aug 31, 2018, at 10:55 AM, Attila Kinali <***@kinali.ch> wrote:

On Thu, 30 Aug 2018 23:05:48 +0000
Gregory Maxwell <***@gmail.com> wrote:


> Seeing some open source software implementing beam-forming was one of
> the things I hoped to see result from the open hardware multi-band
> GNSS receivers like the GNSS firehose project (
> http://pmonta.com/blog/2017/05/05/gnss-firehose-update/ ) since once
> you're going through the trouble of running three coherent receivers
> for three bands, stacking three more of them and locking them to the
> same clock doesn't seem like a big engineering challenge... and the
> rest is just DSP work.

"Just DSP work" is a tad bit more than you think. You are dealing
with sevaral 1Msps of data, even for a simple L1 C/A receiver.
If you are going multi-band-multi-GNSS you are usually in the 50MHz BW
at L1 and 80MHz BW at L2/L5 range, which means you are dealing with
something in the order of 100Msps of data per channel (either as
a single stream of sample or two streams of samples with half rate).
Then you add to it that you will need at least 4bit ADCs to get
somewhat jaming proof, probably even 10bit or more and suddenly
you are dealing with 200-400Mbyte/s data per antenna. Constantly.
To be able to do reasonable beam forming, you probably need a 4 by 4
grid at least, that makes 16 antennas which brings us into the
3Gbyte/s to 6Gbyte/s region. And that's just the raw _input_ datarate
you have to handle.... A modern GNSS receiver has something in the
order of 50-100 correlators per band, each of which needs to receive
the full data rate mentioned above. So inside the chip, the data rate
gets multiplied as well.

Now take into considerations that beside running the correlators,
after you phase shifted and weighted the inputs correctly, you
have to run some fancy algorithms (on the raw data) to figure
out what these phase shifts and weights are. For each satellite
you are tracking individually. All this toghether means you have
run some pretty heavy computation, that is very likely not going
to fit into an FPGA, so you need to build a custom ASIC.



> Even absent fancy beam forming, for GNSS timing with a surveyed
> position except at high latitudes it should be possible to use a
> relatively high gain antenna pointed straight up and by doing so blind
> yourself to terrestrial jammers at a cost of fewer SVs being
> available. But I've never tried it.

You still need the lower satellites to survey your position accurately.
Besides that you lose a lot of in terms of timing accuracy, if you
have only a limited number of satellites. So you cannot decrease the
lower elevation angles too much. Going below -10dB is probably not
agood idea. Also, going from ~10 birds in view down to ~5 means that
your PPS jitter just increased by a factor of 5 to 10.
(source: experiment i've done here some time ago)

Besides, a narrow band jammer trips up most of the commercial receivers
badly (adds a correlation peak where it does not belong).
And for that to be effective you only need to be 5-10dB above the noise
level. Which is pretty easy to achieve, even if you have very directive
antenna (the sidelobes are usually only 10-30dB down from the main lobe)

Fortunately, narrow band jammers are also pretty easy to mask, given
you have enough bits in your ADC.

> As others have noted intermittent jamming is pretty benign to a GPSDO.
> Spoofing, OTOH, can trivially mess up the timing. It's my view that
> if you need timing for a security critical purpose there isn't really
> any GNSS based solution commercially available to the general public
> right now, the best bet is a local atomic reference with a GPSDO used
> to monitor and initially set it.

There is a reason why Microsemi is building more 5071 these days than
ever before (rumors have it that they are are 3-4 devices per week).

Attila Kinali
--
It is upon moral qualities that a society is ultimately founded. All
the prosperity and technological sophistication in the world is of no
use without that foundation.
-- Miss Matheson, The Diamond Age, Neal Stephenson

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Gregory Maxwell
2018-08-31 16:38:36 UTC
Permalink
On Fri, Aug 31, 2018 at 2:56 PM Attila Kinali <***@kinali.ch> wrote:
> "Just DSP work" is a tad bit more than you think. You are dealing
> with sevaral 1Msps of data, even for a simple L1 C/A receiver.
> If you are going multi-band-multi-GNSS you are usually in the 50MHz BW
> at L1 and 80MHz BW at L2/L5 range, which means you are dealing with
> something in the order of 100Msps of data per channel (either as
> a single stream of sample or two streams of samples with half rate).

I have done beamforming in software for wifi signals, which is quite
similar a task.

You are probably underestimating somewhat how fast modern systems have
become. There are now people using GPUs for SDR now as well, which is
perhaps more fitting to a GNSS timestamper than many other SDR
applications, since that application doesn't need to be low latency.
There are now consumer GPUs that do 14 trillion single precision
multiply-adds per second.

> Then you add to it that you will need at least 4bit ADCs to get
> somewhat jaming proof, probably even 10bit or more and suddenly

There I agree. It seems to me that a interesting architecture would
be to run a sinusoid killer on a FPGA immediately behind the DACs,
then spit out a 2 or 4 bit stream.

The best processing tool I have for estimating sinusoid parameters is
https://arxiv.org/abs/1602.05900 the computationally hungry parts
(measuring correlations with candidate sinusoids and the signal) are
easily implemented on an FPGA but still would be pretty impressive to
see running at 50msps. For GNSS applications something far stupider
probably is adequate: FFTs on windowed overlapping blocks, null out
outlying peaks and ifft. It would not take a very large FFT to get
enough frequency selectivity to kill only 1% of signal power per
eliminated sinusoid-- maybe 256 samples.

> you are dealing with 200-400Mbyte/s data per antenna. Constantly.
> To be able to do reasonable beam forming, you probably need a 4 by 4
> grid at least, that makes 16 antennas which brings us into the

There are many papers showing interesting GNSS beamforming results
with far fewer antennas:

4 antennas, 14-bit, 40msps, and a GPU based decoder:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3231503/pdf/sensors-11-08966.pdf

This one has simulated polar patterns for 7 antennas that look pretty
impressive https://web.stanford.edu/group/scpnt/gpslab/pubs/papers/DeLorenzo_IONGNSS_2004.pdf

This one has measurements with 7 antennas on actual hardware:
https://pdfs.semanticscholar.org/5531/aa89f81e4cdfa15e74e98c264dcb697395ca.pdf
(and also talks a bit about their SSE correlators needed to get
realtime performance in a software implementation).

> You still need the lower satellites to survey your position accurately.

Yes, but that is potentially a one time operation.

> Also, going from ~10 birds in view down to ~5 means that
> your PPS jitter just increased by a factor of 5 to 10.
> (source: experiment i've done here some time ago)

But, if your SNR on those 5 remaining birds increases substantially
from increased antenna gain might it not offset some of that loss? I
would worry that getting a consistent phase center on some weird high
gain antenna design would be hard, however.

> There is a reason why Microsemi is building more 5071 these days than
> ever before (rumors have it that they are are 3-4 devices per week).

If you consider the cost of a new 5071 ... that would pay for a heck
of a beam-forming anti-jamming receiver-- at least hardware wise. :)

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jimlux
2018-08-31 17:15:15 UTC
Permalink
On 8/31/18 9:38 AM, Gregory Maxwell wrote:
> On Fri, Aug 31, 2018 at 2:56 PM Attila Kinali <***@kinali.ch> wrote:
>> "Just DSP work" is a tad bit more than you think. You are dealing
>> with sevaral 1Msps of data, even for a simple L1 C/A receiver.
>> If you are going multi-band-multi-GNSS you are usually in the 50MHz BW
>> at L1 and 80MHz BW at L2/L5 range, which means you are dealing with
>> something in the order of 100Msps of data per channel (either as
>> a single stream of sample or two streams of samples with half rate).
>
> I have done beamforming in software for wifi signals, which is quite
> similar a task.
>
> You are probably underestimating somewhat how fast modern systems have
> become. There are now people using GPUs for SDR now as well, which is
> perhaps more fitting to a GNSS timestamper than many other SDR
> applications, since that application doesn't need to be low latency.
> There are now consumer GPUs that do 14 trillion single precision
> multiply-adds per second.
>
>> Then you add to it that you will need at least 4bit ADCs to get
>> somewhat jaming proof, probably even 10bit or more and suddenly
>
> There I agree. It seems to me that a interesting architecture would
> be to run a sinusoid killer on a FPGA immediately behind the DACs,
> then spit out a 2 or 4 bit stream.
>


<snip of discussion>

AJ is a slightly different problem than straight up beamforming

You need N+1 receivers to suppress N point source jammers - it's more of
an adaptive canceller than a beamformer.

The literature has been around since the 60s on how to do this in a
variety of cases and signals, with plenty of hardware demonstrations
over the decades ranging from analog combiners to very sophisticated
digital approaches using algorithms like ESPRIT or MUSIC.

There's also extensive work on AJ techniques for PN signals, although I
don't know how much is in the open literature.

One wants to think about the jamming/interference signal

In general, you're probably not going to design to "notch" a sinusoid -
sure that might be a common jammer, but the sinewave generated by the
jammer might be very noisy and unstable in frequency - sort of the
opposite of the sinusoids desired by list members :) - the spurious
oscillation of the TV antenna amplifier was in this bucket.

The jamming signal is likely to be somewhat broadband = pulsed, or
harmonics of some lower frequency signal, which is none too clean - most
power supply designers do not lock their PWM rate to a maser, after all.

If you're talking about a sophisticated jammer - typically they'll
attack some design feature - For instance, way back (more than 50
years), a strategy for radars was to transmit two tones separated by
60MHz (Radar IF chains were at 60 MHz) and pulse it, in hopes that you'd
hose up the AGC, or create intermods. Similarly, transmitting on some
ham bands in the 50s would get into the TV receiver IF.

Then you get into sophisticated approaches which are more like spoofing
- transmit a PN modulated signal that replicates the desired signal,
then pull it away and turn off, forcing the receiver to be in
"acquisition" mode all the time.

Can you build a receiver which is immune to all of these and sell it for
$10? Probably not. Can you do it for $100-1000, almost certainly.

So now it comes down to the classic tradeoff - what is the value of the
thing you are protecting.


On time-nuts, we're used to "better performance for its own sake" - it's
cool, it's nifty, it's educational, for most of us, we don't necessarily
have to justify our desire to get that next digit. We're also often very
thrifty - as part of the challenge - I know I can get accuracy X by
spending $100k, but can I get there spending only $200.

The commercial world, which has to consider the slings and arrows of
these threats does put a value on it, and that drives the budgets for
the fixes. I would venture that *in most cases*, the cost of a fancy
holdover GPSDO is a tiny, tiny part of the cost of a cell site -
Installation of the concrete pad for the tower probably costs more.

Sure, if you've got 1000 sites, and you need to upgrade them all at
$10k/each, that's a $10M hit you need to explain to the shareholders,
but, it *is* a cost of doing business.

And, realistically, it's much more likely your network failure will be
because some idiot dug in the wrong place, or someone rolled out a
software update with a bug, rather than a freak ionization event
blocking GPS.

Check out the telephone switch bug that shutdown phone service for a day
in 1990 -
https://users.csc.calpoly.edu/~jdalbey/SWE/Papers/att_collapse.html






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Gregory Maxwell
2018-08-31 17:38:22 UTC
Permalink
On Fri, Aug 31, 2018 at 5:16 PM jimlux <***@earthlink.net> wrote:
> AJ is a slightly different problem than straight up beamforming
>
> You need N+1 receivers to suppress N point source jammers - it's more of
> an adaptive canceller than a beamformer.

One nice property of AJ though is that the nulls it forms can be very
deep, so the result is much more suppression than you might have
expected from looking at the lobe gains from beamforming. This is for
the same reason that normal radio direction finding uses e.g. the null
in a loop antenna.

It's also an argument as to why few antennas are sufficient for
blocking jammers at a single location.

> In general, you're probably not going to design to "notch" a sinusoid -
> sure that might be a common jammer, but the sinewave generated by the
> jammer might be very noisy and unstable in frequency - sort of the
> opposite of the sinusoids desired by list members :) - the spurious
> oscillation of the TV antenna amplifier was in this bucket.

Hm. My belief that a sinusoid notch was interesting in part because of
how badly a loud one trashes a bit-depth reduced signal compared to
e.g. pulse interference with an equivalent amount of energy.

With infinite bit depth I wouldn't expect a narrowband jammer to be
particularly bothersome after despreading (at least not more than any
other jamming signal that isn't correlated with the spreading code).

[As an aside, the sinusoidal estimation paper I linked can also model
higher order parameters like amplitude and frequency modulation,
including 2nd order and higher modulation, assuming you have enough
SNR for those terms to be anything but noise.]

> Then you get into sophisticated approaches which are more like spoofing
> - transmit a PN modulated signal that replicates the desired signal,
> then pull it away and turn off, forcing the receiver to be in
> "acquisition" mode all the time.

Indeed, and with SDR so inexpensive, making a jammer that produces a
spoof GPS signal is something a bored teenager can do.

> Can you build a receiver which is immune to all of these and sell it for
> $10? Probably not. Can you do it for $100-1000, almost certainly.

A robust timing receiver with a parts cost of $1000 many would buy
now, but I think the issue is that the first unit costs $10m ... it's
only the nth thousandth one built that costs $1000. :P

> holdover GPSDO is a tiny, tiny part of the cost of a cell site -
> Installation of the concrete pad for the tower probably costs more.

Indeed, but people are now using GPS based timing for security
critical applications where skewing someones clock lets you steal
millions in an electronic bank heist. We don't actually see any of
these attacks right now in part because it's still much easier to
attack by social engineering humans or leaving malware on USB sticks
outside an office... but also because people who are aware of these
risks put in a local atomic clock instead of getting their timing from
a GPSDO, but many aren't aware of the risks.

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Magnus Danielson
2018-09-01 06:30:48 UTC
Permalink
On 08/30/2018 11:20 PM, Brooke Clarke wrote:
> Hi Bob:
>
> I would disagree in that ease of jamming/spoofing is strongly related to
> wavelength.  That's because antenna efficiency goes down as the size of
> the antenna gets smaller than 1/4 wave.
> So, it's easy to make a GPS jammer (1,100 to 1,600MHz) since a 1/4
> wavelength is a few inches, something that  you can hold in your hand.
> It's harder to make a WWV jammer (.5, 5, 10, 15, 20 MHz) since a 1/4
> wavelength in in the range of  500 to 12 feet, something that can be
> mounted on a vehicle for the higher frequencies.
> But it's extremely hard to make a jammer for WWVB (60 kHz) where a
> 1/4wavelength is over 4,000 feet.  This means an antenna that can be
> vehicle mounted will be very inefficient. Note this also means that it's
> extremely hard to make a Loran-C jammer.  Note that the WWVB and LORAN-C
> transmitters run very high power and the antennas are massive.

Locally you can transmit with a much smaller antenna. It's been shown
and works.

Sweden used to have a network of 212 m towers to jam and spoof
Loran-C/Chayka. It was a top secret network.

> This also means that if someone makes a WWVB simulator for their house
> the signal at the next door neighbor's house is probably going to be too
> small to effect their clocks.

Magnetic loop works, non-resonant suffice. Magnetic lopp is used for
hearing aid, and it doesn't take much. Enough for the house. Not getting
you very far though.

> PS. Some decades ago I maintained a beacon transmitter "LAH" on 175 kHz
> where the rules for unlicensed operation limited the input power to 1
> Watt and total antenna length to 50 feet.  Under these conditions the
> effective radiated power might be 2 milliwatts, orders of magnitude less
> if a portable system.
> http://www.auroralchorus.com/pli/1750meter_antennas.pdf
>

The 137 kHz band for radio amateurs is limited, but with radiated power,
and getting up to that power is a great success and considering the band
and that one use CW it should be fun.

Cheers,
Magnus

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Mark Spencer
2018-08-13 10:25:16 UTC
Permalink
I'm trying hard to think of routine users of WWV / WWVH other than amateur radio operators, time nuts, and the occasional academic / scientific study that uses the transmitters as a signal source.

Perhaps some boaters still use the time signals to set their chronometers, but WWV /WWVH probably wouldn't be my first choice for that application if I had access to GPS.

Perhaps some other users of the radio Spectrum occasionally use the signals as a basic test signal ?

I use the time signals for my amateur radio hobby when I already have an HF receiver and don't want to mess with using GPS as a time source. I only need accuracy within perhaps a third of a second so manually setting a computer clock while listening to WWV works for me.

For my own interest I'd be curious in knowing of other routine uses of the WWV / WWVH time signals.


Mark S
VE7AFZ

***@alignedsolutions.com
604 762 4099

> On Aug 12, 2018, at 2:08 AM, Bob kb8tq <***@n1k.org> wrote:
>
> Hi
>
> One would *guess* that stopping WWVB (and killing mom and pop’s “atomic clocks”) would not be a reasonable thing to do.
> It gets a lot of voters mad. I doubt that very many voters (percentage wise) would notice WWV and WWVH going away ….
>
> Bob
>
>> On Aug 11, 2018, at 9:00 PM, jimlux <***@earthlink.net> wrote:
>>
>> On 8/10/18 12:45 PM, Robert LaJeunesse wrote:
>>> I'd say it does get more detailed, with the $49M in cuts described generally in groups here:
>>> https://www.nist.gov/director/fy-2019-presidential-budget-request-summary/fundamental-measurement-quantum-science-and
>>> One item: "-$6.3 million supporting fundamental measurement dissemination, including the shutdown of NIST radio stations in Colorado and Hawaii"
>>
>> I wonder if that's WWVB, or WWV & WWVH
>>
>> _______________________________________________
>> time-nuts mailing list -- time-***@lists.febo.com
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>
>
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Dana Whitlow
2018-08-13 11:24:56 UTC
Permalink
Note to all;

Be cautious about getting time of day from consumer GPS products. All that
I have encountered
(so far) exhibit T.O.D. errors up to a few tenths of a second, and the
error is not repeatable from
session to session. Some do have PPS outputs, which are typically claimed
to provide usec
level of accuracy, but most do not.

I routinely use WWV to verify correct setting of my WWVB-synced watch and
kitchen clock. I have
occasionally seen severe setting errors, which I attribute to attempts at
syncing in the face of poor
WWVB reception conditions.

My impression is that none of the time codes currently in use by broadcast
NIST time signals
contain forward error correction or even error detection features. If this
is wrong, please somebody
correct me!

BTW, there are a fair number of Heathkit clocks in the wild which use WWV
(as opposed to WWVB)
for syncing. An old college-era housemate with whom I keep in touch owns
and still uses at least
one of them.

Dana


On Mon, Aug 13, 2018 at 5:25 AM, Mark Spencer <***@alignedsolutions.com>
wrote:

> I'm trying hard to think of routine users of WWV / WWVH other than amateur
> radio operators, time nuts, and the occasional academic / scientific study
> that uses the transmitters as a signal source.
>
> Perhaps some boaters still use the time signals to set their chronometers,
> but WWV /WWVH probably wouldn't be my first choice for that application if
> I had access to GPS.
>
> Perhaps some other users of the radio Spectrum occasionally use the
> signals as a basic test signal ?
>
> I use the time signals for my amateur radio hobby when I already have an
> HF receiver and don't want to mess with using GPS as a time source. I only
> need accuracy within perhaps a third of a second so manually setting a
> computer clock while listening to WWV works for me.
>
> For my own interest I'd be curious in knowing of other routine uses of the
> WWV / WWVH time signals.
>
>
> Mark S
> VE7AFZ
>
> ***@alignedsolutions.com
> 604 762 4099
>
> > On Aug 12, 2018, at 2:08 AM, Bob kb8tq <***@n1k.org> wrote:
> >
> > Hi
> >
> > One would *guess* that stopping WWVB (and killing mom and pop’s “atomic
> clocks”) would not be a reasonable thing to do.
> > It gets a lot of voters mad. I doubt that very many voters (percentage
> wise) would notice WWV and WWVH going away ….
> >
> > Bob
> >
> >> On Aug 11, 2018, at 9:00 PM, jimlux <***@earthlink.net> wrote:
> >>
> >> On 8/10/18 12:45 PM, Robert LaJeunesse wrote:
> >>> I'd say it does get more detailed, with the $49M in cuts described
> generally in groups here:
> >>> https://www.nist.gov/director/fy-2019-presidential-budget-
> request-summary/fundamental-measurement-quantum-science-and
> >>> One item: "-$6.3 million supporting fundamental measurement
> dissemination, including the shutdown of NIST radio stations in Colorado
> and Hawaii"
> >>
> >> I wonder if that's WWVB, or WWV & WWVH
> >>
> >> _______________________________________________
> >> time-nuts mailing list -- time-***@lists.febo.com
> >> To unsubscribe, go to http://lists.febo.com/mailman/
> listinfo/time-nuts_lists.febo.com
> >> and follow the instructions there.
> >
> >
> > _______________________________________________
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> > To unsubscribe, go to http://lists.febo.com/mailman/
> listinfo/time-nuts_lists.febo.com
> > and follow the instructions there.
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Bob kb8tq
2018-08-13 11:59:10 UTC
Permalink
Hi



> On Aug 13, 2018, at 7:24 AM, Dana Whitlow <***@gmail.com> wrote:
>
> Note to all;
>
> Be cautious about getting time of day from consumer GPS products. All that
> I have encountered
> (so far) exhibit T.O.D. errors up to a few tenths of a second, and the
> error is not repeatable from
> session to session. Some do have PPS outputs, which are typically claimed
> to provide usec
> level of accuracy, but most do not.

… but there *are* modules out there for not a lot of money that do indeed give
quite good PPS (and TOD) information. Picking out the good brands / models
from the junk is part of why you have lists like this one.

>
> I routinely use WWV to verify correct setting of my WWVB-synced watch and
> kitchen clock. I have
> occasionally seen severe setting errors, which I attribute to attempts at
> syncing in the face of poor
> WWVB reception conditions.
>
> My impression is that none of the time codes currently in use by broadcast
> NIST time signals
> contain forward error correction or even error detection features. If this
> is wrong, please somebody
> correct me!
>

I believe you will find that the “new” PSK modulation scheme on WWVB has at
least some error detection built into it.

> BTW, there are a fair number of Heathkit clocks in the wild which use WWV
> (as opposed to WWVB)

There aren’t a lot of those left running these days …..

Bob


> for syncing. An old college-era housemate with whom I keep in touch owns
> and still uses at least
> one of them.
>
> Dana
>
>
> On Mon, Aug 13, 2018 at 5:25 AM, Mark Spencer <***@alignedsolutions.com>
> wrote:
>
>> I'm trying hard to think of routine users of WWV / WWVH other than amateur
>> radio operators, time nuts, and the occasional academic / scientific study
>> that uses the transmitters as a signal source.
>>
>> Perhaps some boaters still use the time signals to set their chronometers,
>> but WWV /WWVH probably wouldn't be my first choice for that application if
>> I had access to GPS.
>>
>> Perhaps some other users of the radio Spectrum occasionally use the
>> signals as a basic test signal ?
>>
>> I use the time signals for my amateur radio hobby when I already have an
>> HF receiver and don't want to mess with using GPS as a time source. I only
>> need accuracy within perhaps a third of a second so manually setting a
>> computer clock while listening to WWV works for me.
>>
>> For my own interest I'd be curious in knowing of other routine uses of the
>> WWV / WWVH time signals.
>>
>>
>> Mark S
>> VE7AFZ
>>
>> ***@alignedsolutions.com
>> 604 762 4099
>>
>>> On Aug 12, 2018, at 2:08 AM, Bob kb8tq <***@n1k.org> wrote:
>>>
>>> Hi
>>>
>>> One would *guess* that stopping WWVB (and killing mom and pop’s “atomic
>> clocks”) would not be a reasonable thing to do.
>>> It gets a lot of voters mad. I doubt that very many voters (percentage
>> wise) would notice WWV and WWVH going away ….
>>>
>>> Bob
>>>
>>>> On Aug 11, 2018, at 9:00 PM, jimlux <***@earthlink.net> wrote:
>>>>
>>>> On 8/10/18 12:45 PM, Robert LaJeunesse wrote:
>>>>> I'd say it does get more detailed, with the $49M in cuts described
>> generally in groups here:
>>>>> https://www.nist.gov/director/fy-2019-presidential-budget-
>> request-summary/fundamental-measurement-quantum-science-and
>>>>> One item: "-$6.3 million supporting fundamental measurement
>> dissemination, including the shutdown of NIST radio stations in Colorado
>> and Hawaii"
>>>>
>>>> I wonder if that's WWVB, or WWV & WWVH
>>>>
>>>> _______________________________________________
>>>> time-nuts mailing list -- time-***@lists.febo.com
>>>> To unsubscribe, go to http://lists.febo.com/mailman/
>> listinfo/time-nuts_lists.febo.com
>>>> and follow the instructions there.
>>>
>>>
>>> _______________________________________________
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>> listinfo/time-nuts_lists.febo.com
>>> and follow the instructions there.
>>
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ewkehren via time-nuts
2018-08-10 20:46:32 UTC
Permalink
Thank you Magnus I focused on 2017 because of the changes but do not understand because it is a divisionBert

Sent from my Galaxy Tab® A
-------- Original message --------From: Magnus Danielson <***@rubidium.dyndns.org> Date: 8/10/18 3:11 PM (GMT-05:00) To: time-***@lists.febo.com Cc: ***@rubidium.se Subject: Re: [time-nuts] NIST
Bert,

The closes I come is this, burried in the line of Funamental Measurements:
https://www.nist.gov/fy-2019-presidential-budget-request-summary/budget-tables

It doesn't get more detailed than that.

The T&F work is relatively small group in the big NIST.

Cheers,
Magnus

On 08/10/2018 08:29 PM, ew via time-nuts wrote:
>  
> NIST total budget for 2017 was close to 965 Million, I was curios trying to find out what the Time and Frequency Division  portion was. No Luck. Does any one know?Thanks   Bert Kehren
> _______________________________________________
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Jwahar Bammi via time-nuts
2018-08-11 20:17:01 UTC
Permalink
Andy Backus,
Would love to see your microwatt transmitter design, per chance have you posted it anywhere.

cheers,
bammi



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Andy Backus
2018-08-11 22:13:41 UTC
Permalink
Here it is. The only (very slight) innovation is to drive a tuned LC antenna directly from a CMOS chip (greatly reducing harmonics). I had to keep the power very low since in my house it is triggered with a not so distant 60 kHz receiver!


Andy Backus

[cid:66a46aee-7820-459f-823d-ed1f078cd2be]



________________________________
From: time-nuts <time-nuts-***@lists.febo.com> on behalf of Jwahar Bammi via time-nuts <time-***@lists.febo.com>
Sent: Saturday, August 11, 2018 1:17 PM
To: time-***@lists.febo.com
Cc: Jwahar Bammi
Subject: Re: [time-nuts] NIST

Andy Backus,
Would love to see your microwatt transmitter design, per chance have you posted it anywhere.

cheers,
bammi



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Mark Sims
2018-08-31 02:12:11 UTC
Permalink
I once bought a pair of low power 315 MHz TX/RX modules and was going to try them in a model rocket + GPS. I tested them with a serial port and they had a range of a couple thousand feet at 1200 BPS. But when the transmitter was connected to the GPS, the GPS lost lock... turns out 315 MHz * 5 is the GPS carrier frequency. They would totally jam GPS over around a mile diameter. Also the maker of the modules stopped selling them and actually disavowed that they ever existed!
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Mark Sims
2018-09-01 17:58:49 UTC
Permalink
I recently added a feature to Lady Heather that can output the sun and moon positions to a port. This was for use by solar trackers and moon bounce antennas. It would be easy to modify that code to output the position of a satellite (or all satellites) if you wanted to keep an antenna pointed at a specific satellite.
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Bob Bownes
2018-09-01 18:09:04 UTC
Permalink
Mark,

That would be most useful and free folks from a few of the proprietary
satellite tracker programs. One could write a 'shim' to consume the output
from a tcp/udp (or serial) port and convert to the proper format for a
chosen polar or az/el rotor.

Bob


On Sat, Sep 1, 2018 at 2:00 PM Mark Sims <***@hotmail.com> wrote:

> I recently added a feature to Lady Heather that can output the sun and
> moon positions to a port. This was for use by solar trackers and moon
> bounce antennas. It would be easy to modify that code to output the
> position of a satellite (or all satellites) if you wanted to keep an
> antenna pointed at a specific satellite.
> _______________________________________________
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Magnus Danielson
2018-09-01 18:11:32 UTC
Permalink
Hi,

Yes please.

I've toyed with the idea of pointing the radio clubs 6 m antenna on GPS
birds just for the fun and capture signals. That is used for moon bounce
mostly on the 23 cm band.

Cheers,
Magnus

On 09/01/2018 07:58 PM, Mark Sims wrote:
> I recently added a feature to Lady Heather that can output the sun and moon positions to a port. This was for use by solar trackers and moon bounce antennas. It would be easy to modify that code to output the position of a satellite (or all satellites) if you wanted to keep an antenna pointed at a specific satellite.
> _______________________________________________
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>

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