Discussion:
[time-nuts] Has anybody checked this? GPSDO in kit
Giuseppe Marullo
2016-10-22 14:02:55 UTC
Permalink
Hello,

I know, I know it is not supposed to be high end stuff(timenutted), but
I was looking for a GPS clock and noticed that this could be a cheap
GPSDO too:

http://qrp-labs.com/progrock.html

It has a OCXO option, a box, a display(customizable), a GPS and could be
probably fitted with a Raspberry Zero for a cheap NTP server too.

Any advice?
Sorry if this has been already discussed here, didn't find any reference
in the ML.

Could it be compared to a Thunderbolt GPSO in terms of performance, how
worse it could be?

I just need a clean/self-calibrating 10MHz reference to tune HF radios
...seems good enough for the price.

Giuseppe Marullo
IW2JWW - JN45RQ



_______________________________________________
time-nuts mailing list -- time-***@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
Bob Camp
2016-10-22 15:26:04 UTC
Permalink
Hi


> On Oct 22, 2016, at 10:02 AM, Giuseppe Marullo <***@marullo.it> wrote:
>
> Hello,
>
> I know, I know it is not supposed to be high end stuff(timenutted), but I was looking for a GPS clock and noticed that this could be a cheap GPSDO too:
>
> http://qrp-labs.com/progrock.html
>
> It has a OCXO option, a box, a display(customizable), a GPS and could be probably fitted with a Raspberry Zero for a cheap NTP server too.
>
> Any advice?
> Sorry if this has been already discussed here, didn't find any reference in the ML.
>
> Could it be compared to a Thunderbolt GPSO in terms of performance, how worse it could be?

Unfortunately, it could be *lots* worse (like many orders of magnitude worse). It all depends on which parameter you
are looking at and how much you want to add on to it. Phase noise and second to second stability are two areas that
it is likely to have problems.


>
> I just need a clean/self-calibrating 10MHz reference to tune HF radios ...seems good enough for the price.

The easy way is to manually calibrate a 10 MHz OCXO to GPS. If you have a scope, it isn’t all that hard.
Total cost is about $10 or so. The net result (free running OCXO) will be much cleaner than a simple GPSDO.

Bob

>
> Giuseppe Marullo
> IW2JWW - JN45RQ
>
>
>
> _______________________________________________
> time-nuts mailing list -- time-***@febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.

_______________________________________________
time-nuts mailing list -- time-***@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
Chris Albertson
2016-10-22 16:22:00 UTC
Permalink
> Unfortunately, it could be *lots* worse (like many orders of magnitude
> worse). It all depends on which parameter you
> are looking at and how much you want to add on to it. Phase noise and
> second to second stability are two areas that
> it is likely to have problems.
>

You have to remember what this thing replaces. In ham radio, some people
are using vacuum tube oscillators with mechanical variable capacitor
tuning. Maybe some advanced rigs use gear drive on the capacitor shaft to
allow more exact tuning This Si chip is considerably better then 1940's
technology.



>
>
--

Chris Albertson
Redondo Beach, California
_______________________________________________
time-nuts mailing list -- time-***@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
William H. Fite
2016-10-22 21:04:19 UTC
Permalink
You need to catch up on what hams are REALLY using.


On Saturday, October 22, 2016, Chris Albertson <***@gmail.com>
wrote:

> > Unfortunately, it could be *lots* worse (like many orders of magnitude
> > worse). It all depends on which parameter you
> > are looking at and how much you want to add on to it. Phase noise and
> > second to second stability are two areas that
> > it is likely to have problems.
> >
>
> You have to remember what this thing replaces. In ham radio, some people
> are using vacuum tube oscillators with mechanical variable capacitor
> tuning. Maybe some advanced rigs use gear drive on the capacitor shaft to
> allow more exact tuning This Si chip is considerably better then 1940's
> technology.
>
>
>
> >
> >
> --
>
> Chris Albertson
> Redondo Beach, California
> _______________________________________________
> time-nuts mailing list -- time-***@febo.com <javascript:;>
> To unsubscribe, go to https://www.febo.com/cgi-bin/
> mailman/listinfo/time-nuts
> and follow the instructions there.
>


--
If you gaze long into an abyss, your coffee will get cold.
_______________________________________________
time-nuts mailing list -- time-***@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
Dr. David Kirkby (Kirkby Microwave Ltd)
2016-10-22 21:55:21 UTC
Permalink
On 22 October 2016 at 17:22, Chris Albertson <***@gmail.com>
wrote:

>
> You have to remember what this thing replaces. In ham radio, some people
> are using vacuum tube oscillators with mechanical variable capacitor
> tuning. Maybe some advanced rigs use gear drive on the capacitor shaft to
> allow more exact tuning This Si chip is considerably better then 1940's
> technology.
>


Well, as someone else pointed out, hams are not using this sort of thing
now - or at least not in any significant numbers.

I recently bought a "new" 2 m transceiver - which is actually a 40 year old
Yaesu FT-225RD. When fitted with a Mutek front end (GW4DGU), they were
arguably the best 2 m transceiver ever made.

Mine drifts quite a bit, and I need to look into why. It can be two things

* Crystal - 100 and odd MHz
* VFO - around 8 MHz

I heard of someone replacing the VFO with a cheap Chinese DDS as an
"upgrade". Actually, I suspect it was probably a downgrade, as I would
expect the VFO to be a lot cleaner.

I've not taken it apart to fix mine, but from what I have read, it would
appear the crystal is the main source of drift, and not the VFO. A
frequency counter will soon determine if that's the case in mine.

Dave
_______________________________________________
time-nuts mailing list -- time-***@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
Wes
2016-10-23 15:24:25 UTC
Permalink
On 10/22/2016 9:22 AM, Chris Albertson wrote:
>
> You have to remember what this thing replaces. In ham radio, some people
> are using vacuum tube oscillators with mechanical variable capacitor
> tuning. Maybe some advanced rigs use gear drive on the capacitor shaft to
> allow more exact tuning This Si chip is considerably better then 1940's
> technology.
I guess my WW-II vintage BC342 receiver (that I started with and still own) was
"advanced". It has an extensive gear train for tuning.

On the other hand my two Elecraft K3s are full of DDS and microprocessors but no
variable capacitors.

Flex radios, are direct sampling SDR and newer ones offer GPS stabilization.
_______________________________________________
time-nuts mailing list -- time-***@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
William H. Fite
2016-10-23 17:49:20 UTC
Permalink
Bravo for boat anchors, Wes. I have a Collins R390 with a tuning gear train
so complex it has to go in every 3000 miles for an oil change.


On Sunday, October 23, 2016, Wes <***@triconet.org> wrote:

> On 10/22/2016 9:22 AM, Chris Albertson wrote:
>
>>
>> You have to remember what this thing replaces. In ham radio, some people
>> are using vacuum tube oscillators with mechanical variable capacitor
>> tuning. Maybe some advanced rigs use gear drive on the capacitor shaft to
>> allow more exact tuning This Si chip is considerably better then 1940's
>> technology.
>>
> I guess my WW-II vintage BC342 receiver (that I started with and still
> own) was "advanced". It has an extensive gear train for tuning.
>
> On the other hand my two Elecraft K3s are full of DDS and microprocessors
> but no variable capacitors.
>
> Flex radios, are direct sampling SDR and newer ones offer GPS
> stabilization.
> _______________________________________________
> time-nuts mailing list -- time-***@febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/m
> ailman/listinfo/time-nuts
> and follow the instructions there.
>


--
If you gaze long into an abyss, your coffee will get cold.
_______________________________________________
time-nuts mailing list -- time-***@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
Jim Sanford
2016-10-23 18:03:13 UTC
Permalink
Nice!

(I had one of those, 20 years ago . . . .)

73,

Jim

***@amsat.org



On 10/23/2016 1:49 PM, William H. Fite wrote:
> Bravo for boat anchors, Wes. I have a Collins R390 with a tuning gear train
> so complex it has to go in every 3000 miles for an oil change.
>
>
> On Sunday, October 23, 2016, Wes <***@triconet.org> wrote:
>
>> On 10/22/2016 9:22 AM, Chris Albertson wrote:
>>
>>> You have to remember what this thing replaces. In ham radio, some people
>>> are using vacuum tube oscillators with mechanical variable capacitor
>>> tuning. Maybe some advanced rigs use gear drive on the capacitor shaft to
>>> allow more exact tuning This Si chip is considerably better then 1940's
>>> technology.
>>>
>> I guess my WW-II vintage BC342 receiver (that I started with and still
>> own) was "advanced". It has an extensive gear train for tuning.
>>
>> On the other hand my two Elecraft K3s are full of DDS and microprocessors
>> but no variable capacitors.
>>
>> Flex radios, are direct sampling SDR and newer ones offer GPS
>> stabilization.
>> _______________________________________________
>> time-nuts mailing list -- time-***@febo.com
>> To unsubscribe, go to https://www.febo.com/cgi-bin/m
>> ailman/listinfo/time-nuts
>> and follow the instructions there.
>>
>


---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus

_______________________________________________
time-nuts mailing list -- time-***@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
Chris Albertson
2016-10-22 16:14:42 UTC
Permalink
On Sat, Oct 22, 2016 at 7:02 AM, Giuseppe Marullo <***@marullo.it>
wrote:

>
> I just need a clean/self-calibrating 10MHz reference to tune HF radios
> ...seems good enough for the price.
>

For HF this thing is more useful than a 10MHz reference because it can
directly output any frequency in the HF band.

It is basically a GPS locked VFO. I've seen this chip used in an SDR front
end is the VFO. The chip's signal went into a mixer and translated the RF
to baseband in one step. It is very stable but with the
"kind-of-square-like" waveform it is rich in harmonics and needs to be
filtered.




> Giuseppe Marullo
> IW2JWW - JN45RQ
>
>
>
> _______________________________________________
> time-nuts mailing list -- time-***@febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/m
> ailman/listinfo/time-nuts
> and follow the instructions there.
>

--

Chris Albertson
Redondo Beach, California
_______________________________________________
time-nuts mailing list -- time-***@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
Tim Shoppa
2016-10-22 14:34:53 UTC
Permalink
I just went and visited their website, and see they also offer a "kit OCXO"
from mostly through-hole parts and PCB. The OCXO insulation box is made out
of PCB, the thermostat is simply a jellybean TO92 transistor, and the 27MHz
crystal is an AT-cut being operated around 45C, so nothing awful
time-nutty, but still pretty neat that it's a kit. Details at

http://qrp-labs.com/images/ocxokit/ocxosynth_assembly.pdf

show that it walks about 14ppm during warmup and then might be good to a
ppm or so.

Tim N3QE

On Sat, Oct 22, 2016 at 10:02 AM, Giuseppe Marullo <***@marullo.it>
wrote:

> Hello,
>
> I know, I know it is not supposed to be high end stuff(timenutted), but I
> was looking for a GPS clock and noticed that this could be a cheap GPSDO
> too:
>
> http://qrp-labs.com/progrock.html
>
> It has a OCXO option, a box, a display(customizable), a GPS and could be
> probably fitted with a Raspberry Zero for a cheap NTP server too.
>
> Any advice?
> Sorry if this has been already discussed here, didn't find any reference
> in the ML.
>
> Could it be compared to a Thunderbolt GPSO in terms of performance, how
> worse it could be?
>
> I just need a clean/self-calibrating 10MHz reference to tune HF radios
> ...seems good enough for the price.
>
> Giuseppe Marullo
> IW2JWW - JN45RQ
>
>
>
> _______________________________________________
> time-nuts mailing list -- time-***@febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/m
> ailman/listinfo/time-nuts
> and follow the instructions there.
>
_______________________________________________
time-nuts mailing list -- time-***@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
Attila Kinali
2016-10-23 00:18:27 UTC
Permalink
On Sat, 22 Oct 2016 10:34:53 -0400
Tim Shoppa <***@gmail.com> wrote:

> I just went and visited their website, and see they also offer a "kit OCXO"
> from mostly through-hole parts and PCB. The OCXO insulation box is made out
> of PCB, the thermostat is simply a jellybean TO92 transistor, and the 27MHz
> crystal is an AT-cut being operated around 45C, so nothing awful
> time-nutty, but still pretty neat that it's a kit. Details at
>
> http://qrp-labs.com/images/ocxokit/ocxosynth_assembly.pdf
>
> show that it walks about 14ppm during warmup and then might be good to a
> ppm or so.

It's funny how you can tell from the transistors used, where the designer
is from (BC547 -> European :-)

Kits like these have been around ever since I remember. This is one of
the better ones, where the crytal isn't just soldered to some transistor,
but a whole "insulation box" built around it. In german we call these
things "Quarzofen" (lit. "quartz oven") and that's IMHO a very precise
description what they are :-)

Generally it's not very difficult to build some kind of temperature
stabilization system. Heck, just using a heater transistor with a
constant current through it will give you a more stable temperature,
even if you don't control the current other than keeping it constant.
Puting some form of box around it that restricts air and thus heat flow
will make it even better. Using some temperature control and you are
within 1-2°C of stability and way better than most hams need.

The difficulty starts when you need more than that, when you need
temperature stabilities below 1°C, when you want to keep it stable
to 1mK or even below that.

BTW: If anyone has recomended texts on how to build stable ovens
for crystals, I'd like to hear about them. I've alread had a look
at what Rick Karlquist wrote, but I would also like to read more.
Unfortunately, good stuff literature is, as often, hard to find.


On Sat, 22 Oct 2016 17:04:19 -0400
"William H. Fite" <***@gmail.com> wrote:

> You need to catch up on what hams are REALLY using.

What hams have been using varies a lot. As much as what time-nuts are using,
or probably even more. I know a few people who still build valve PAs because
they are "indestructible" (aka can take a lot of abuse without damage).
But I also know people who do designs that are at the border of what
is technically possible today.


Attila Kinali

--
Malek's Law:
Any simple idea will be worded in the most complicated way.
_______________________________________________
time-nuts mailing list -- time-***@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
Bob Camp
2016-10-23 00:29:33 UTC
Permalink
Hi

The bigger issue with doing a “home brew” OCXO is getting crystals with
known turn temperatures in a reasonable range for the project. Yes, you
can build gear to do temperature runs on crystals and sort bags full of them.
It’s likely that your whole bag of 5,000 came from the same bar and your
net result will all look a lot alike…..

Bob


> On Oct 22, 2016, at 8:18 PM, Attila Kinali <***@kinali.ch> wrote:
>
> On Sat, 22 Oct 2016 10:34:53 -0400
> Tim Shoppa <***@gmail.com> wrote:
>
>> I just went and visited their website, and see they also offer a "kit OCXO"
>> from mostly through-hole parts and PCB. The OCXO insulation box is made out
>> of PCB, the thermostat is simply a jellybean TO92 transistor, and the 27MHz
>> crystal is an AT-cut being operated around 45C, so nothing awful
>> time-nutty, but still pretty neat that it's a kit. Details at
>>
>> http://qrp-labs.com/images/ocxokit/ocxosynth_assembly.pdf
>>
>> show that it walks about 14ppm during warmup and then might be good to a
>> ppm or so.
>
> It's funny how you can tell from the transistors used, where the designer
> is from (BC547 -> European :-)
>
> Kits like these have been around ever since I remember. This is one of
> the better ones, where the crytal isn't just soldered to some transistor,
> but a whole "insulation box" built around it. In german we call these
> things "Quarzofen" (lit. "quartz oven") and that's IMHO a very precise
> description what they are :-)
>
> Generally it's not very difficult to build some kind of temperature
> stabilization system. Heck, just using a heater transistor with a
> constant current through it will give you a more stable temperature,
> even if you don't control the current other than keeping it constant.
> Puting some form of box around it that restricts air and thus heat flow
> will make it even better. Using some temperature control and you are
> within 1-2°C of stability and way better than most hams need.
>
> The difficulty starts when you need more than that, when you need
> temperature stabilities below 1°C, when you want to keep it stable
> to 1mK or even below that.
>
> BTW: If anyone has recomended texts on how to build stable ovens
> for crystals, I'd like to hear about them. I've alread had a look
> at what Rick Karlquist wrote, but I would also like to read more.
> Unfortunately, good stuff literature is, as often, hard to find.
>
>
> On Sat, 22 Oct 2016 17:04:19 -0400
> "William H. Fite" <***@gmail.com> wrote:
>
>> You need to catch up on what hams are REALLY using.
>
> What hams have been using varies a lot. As much as what time-nuts are using,
> or probably even more. I know a few people who still build valve PAs because
> they are "indestructible" (aka can take a lot of abuse without damage).
> But I also know people who do designs that are at the border of what
> is technically possible today.
>
>
> Attila Kinali
>
> --
> Malek's Law:
> Any simple idea will be worded in the most complicated way.
> _______________________________________________
> time-nuts mailing list -- time-***@febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.

_______________________________________________
time-nuts mailing list -- time-***@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
Mark Sims
2016-10-23 02:52:22 UTC
Permalink
Yep, I recently sorted through a bag of 100 crystals from China ($10, shipped) looking for a "good" one. They were ALL good... a complete waste of time. I was rather amazed at their consistency and performance for a 10 cent part.

Last year I bought an alarm clock / game from China (looks like 7 sticks of dynamite with an ominous circuit board / LED display strapped to it). It uses a 40 pin (AVR?) processor driven by a 16 MHz processor crystal. I have not set it in over a year and it is still within a few seconds. I suspect they measure the frequency and have a calibration tweak stored in EEPROM... but that seems excessive work for a $20 toy. I highly doubt they go as far as doing temperature compensation. Maybe they characterized a bucket of XTALs and use a generic compensation factor?

----------------------

> Yes, you can build gear to do temperature runs on crystals and sort bags full of them.
It’s likely that your whole bag of 5,000 came from the same bar and your
net result will all look a lot alike…..
_______________________________________________
time-nuts mailing list -- time-***@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
Bob Camp
2016-10-23 13:08:16 UTC
Permalink
Hi

You *could* calibrate the nominal frequency a chip very cheaply these days. They may / the
may not, who knows. It certainly *is* done that way on very low cost wrist watches.
I’d bet that they do and it leaves the factory set within less than 1 ppm.

A good generic crystal is still going to be a few ppm sort of proposition once set. Each ppm is 2.6
seconds a month. If you only get bothered by it being off one minute, it’s quite possible
for a simple clock to hang in there for a year.

The interesting thing is that *most* places set the device to run fast. There are some
great sites on the internet documenting this. You normally are bothered by the
deliberate offset before you notice the actual accuracy of the clock.

Bob

> On Oct 22, 2016, at 10:52 PM, Mark Sims <***@hotmail.com> wrote:
>
> Yep, I recently sorted through a bag of 100 crystals from China ($10, shipped) looking for a "good" one. They were ALL good... a complete waste of time. I was rather amazed at their consistency and performance for a 10 cent part.
>
> Last year I bought an alarm clock / game from China (looks like 7 sticks of dynamite with an ominous circuit board / LED display strapped to it). It uses a 40 pin (AVR?) processor driven by a 16 MHz processor crystal. I have not set it in over a year and it is still within a few seconds. I suspect they measure the frequency and have a calibration tweak stored in EEPROM... but that seems excessive work for a $20 toy. I highly doubt they go as far as doing temperature compensation. Maybe they characterized a bucket of XTALs and use a generic compensation factor?
>
> ----------------------
>
>> Yes, you can build gear to do temperature runs on crystals and sort bags full of them.
> It’s likely that your whole bag of 5,000 came from the same bar and your
> net result will all look a lot alike…..
> _______________________________________________
> time-nuts mailing list -- time-***@febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.

_______________________________________________
time-nuts mailing list -- time-***@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
Tim Shoppa
2016-10-23 13:44:59 UTC
Permalink
I've been very impressed by the LED/VFD car clocks that come built into
cars for the past 20 years. They have to work in temperature extremes from
below zero to way above 120F when parked in the sun on a hot day. And every
six months at DST time when it's time to reset them, I find they are never
off more than a minute. This leads me to believe, they must have some sort
of temperature compensation (I'm guessing a lookup table or maybe just a
simple few-parameter formula to adjust divide-down clock based on cheap
temperature sensor) built in.

Tim N3QE

On Sat, Oct 22, 2016 at 10:52 PM, Mark Sims <***@hotmail.com> wrote:

> Yep, I recently sorted through a bag of 100 crystals from China ($10,
> shipped) looking for a "good" one. They were ALL good... a complete waste
> of time. I was rather amazed at their consistency and performance for a 10
> cent part.
>
> Last year I bought an alarm clock / game from China (looks like 7 sticks
> of dynamite with an ominous circuit board / LED display strapped to it).
> It uses a 40 pin (AVR?) processor driven by a 16 MHz processor crystal. I
> have not set it in over a year and it is still within a few seconds. I
> suspect they measure the frequency and have a calibration tweak stored in
> EEPROM... but that seems excessive work for a $20 toy. I highly doubt they
> go as far as doing temperature compensation. Maybe they characterized a
> bucket of XTALs and use a generic compensation factor?
>
> ----------------------
>
> > Yes, you can build gear to do temperature runs on crystals and sort
> bags full of them.
> It’s likely that your whole bag of 5,000 came from the same bar and your
> net result will all look a lot alike…..
> _______________________________________________
> time-nuts mailing list -- time-***@febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/
> mailman/listinfo/time-nuts
> and follow the instructions there.
>
_______________________________________________
time-nuts mailing list -- time-***@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
Giuseppe Marullo
2016-10-23 13:32:33 UTC
Permalink
Thanks to all that have answered, as usual very good advices.

I am puzzled about what to do, still the total cost of it for a OXCO +
GPS(unit with antenna) + control mcu is 67usd, I doubt I could find
anything like this for a cheaper price new.

Only cheap alternative could be this one(already discussed here one year
ago):

http://www.ebay.com/itm/141734507722?_trksid=p2057872.m2749.l2649

Would this allow me to play as the "standard" ThunderBolt using the same
software? Any preferred model among
63090/73090/65256 "models"?

Giuseppe Marullo
IW2JWW - JN45RQ

PS: Still I like the idea of the kit...the trimble would require PSU,
antenna, boxing and no fancy display...


On 10/22/2016 4:02 PM, Giuseppe Marullo wrote:
> Hello,
>
> I know, I know it is not supposed to be high end stuff(timenutted),
> but I was looking for a GPS clock and noticed that this could be a
> cheap GPSDO too:
>
> http://qrp-labs.com/progrock.html
>
> It has a OCXO option, a box, a display(customizable), a GPS and could
> be probably fitted with a Raspberry Zero for a cheap NTP server too.
>
> Any advice?
> Sorry if this has been already discussed here, didn't find any
> reference in the ML.
>
> Could it be compared to a Thunderbolt GPSO in terms of performance,
> how worse it could be?
>
> I just need a clean/self-calibrating 10MHz reference to tune HF
> radios ...seems good enough for the price.
>
> Giuseppe Marullo
> IW2JWW - JN45RQ
>
>
>
> _______________________________________________
> time-nuts mailing list -- time-***@febo.com
> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.

_______________________________________________
time-nuts mailing list -- time-***@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
Bob Camp
2016-10-23 13:56:14 UTC
Permalink
Hi

There is a *long* list of information on that unit over on EEVBlog. Bottom line is
that if you get a good one (you may not) it is a *much* better solution than the other
one you are looking at.

Bob

> On Oct 23, 2016, at 9:32 AM, Giuseppe Marullo <***@marullo.it> wrote:
>
> Thanks to all that have answered, as usual very good advices.
>
> I am puzzled about what to do, still the total cost of it for a OXCO + GPS(unit with antenna) + control mcu is 67usd, I doubt I could find anything like this for a cheaper price new.
>
> Only cheap alternative could be this one(already discussed here one year ago):
>
> http://www.ebay.com/itm/141734507722?_trksid=p2057872.m2749.l2649
>
> Would this allow me to play as the "standard" ThunderBolt using the same software? Any preferred model among
> 63090/73090/65256 "models"?
>
> Giuseppe Marullo
> IW2JWW - JN45RQ
>
> PS: Still I like the idea of the kit...the trimble would require PSU, antenna, boxing and no fancy display...
>
>
> On 10/22/2016 4:02 PM, Giuseppe Marullo wrote:
>> Hello,
>>
>> I know, I know it is not supposed to be high end stuff(timenutted), but I was looking for a GPS clock and noticed that this could be a cheap GPSDO too:
>>
>> http://qrp-labs.com/progrock.html
>>
>> It has a OCXO option, a box, a display(customizable), a GPS and could be probably fitted with a Raspberry Zero for a cheap NTP server too.
>>
>> Any advice?
>> Sorry if this has been already discussed here, didn't find any reference in the ML.
>>
>> Could it be compared to a Thunderbolt GPSO in terms of performance, how worse it could be?
>>
>> I just need a clean/self-calibrating 10MHz reference to tune HF radios ...seems good enough for the price.
>>
>> Giuseppe Marullo
>> IW2JWW - JN45RQ
>>
>>
>>
>> _______________________________________________
>> time-nuts mailing list -- time-***@febo.com
>> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>> and follow the instructions there.
>
> _______________________________________________
> time-nuts mailing list -- time-***@febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.

_______________________________________________
time-nuts mailing list -- time-***@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
Bryan _
2016-10-23 21:27:41 UTC
Permalink
The link on EEVblog is http://www.eevblog.com/forum/projects/a-look-at-my-symmetricom-gpsdo-(ocxo-furuno-receiver)/
the Symmetricom and the Trimble you referenced are almost identical in operation. Issue is receiving one that works, a bit hit and miss. Apparently the next version of Lady heather will be able to monitor it. With the Symmetricom you are somewhat limited to what settings you can apply to tweak it, at least as to what limited documentation is available to do so. If you have a decent antenna and a good view of the sky you should be fine.


NOTE be careful with the voltages that may be quoted. The Trimble's are NOT 12v. search Time-Nuts for more info



-=Bryan=-


________________________________
From: time-nuts <time-nuts-***@febo.com> on behalf of Bob Camp <***@n1k.org>
Sent: October 23, 2016 6:56 AM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Has anybody checked this? GPSDO in kit

Hi

There is a *long* list of information on that unit over on EEVBlog. Bottom line is
that if you get a good one (you may not) it is a *much* better solution than the other
one you are looking at.

Bob

> On Oct 23, 2016, at 9:32 AM, Giuseppe Marullo <***@marullo.it> wrote:
>
> Thanks to all that have answered, as usual very good advices.
>
> I am puzzled about what to do, still the total cost of it for a OXCO + GPS(unit with antenna) + control mcu is 67usd, I doubt I could find anything like this for a cheaper price new.
>
> Only cheap alternative could be this one(already discussed here one year ago):
>
> http://www.ebay.com/itm/141734507722?_trksid=p2057872.m2749.l2649
[http://i.ebayimg.com/images/i/141734507722-0-1/s-l1000.jpg]<http://www.ebay.com/itm/141734507722?_trksid=p2057872.m2749.l2649>

Used Tested 10MHz Trimble 63090/73090/65256 GPS board OCXO | eBay<http://www.ebay.com/itm/141734507722?_trksid=p2057872.m2749.l2649>
www.ebay.com
Note : this item is used ,but Good quality. | eBay!



>
> Would this allow me to play as the "standard" ThunderBolt using the same software? Any preferred model among
> 63090/73090/65256 "models"?
>
> Giuseppe Marullo
> IW2JWW - JN45RQ
>
> PS: Still I like the idea of the kit...the trimble would require PSU, antenna, boxing and no fancy display...
>
>
> On 10/22/2016 4:02 PM, Giuseppe Marullo wrote:
>> Hello,
>>
>> I know, I know it is not supposed to be high end stuff(timenutted), but I was looking for a GPS clock and noticed that this could be a cheap GPSDO too:
>>
>> http://qrp-labs.com/progrock.html
ProgRock - triple programmable crystal - QRP Labs<http://qrp-labs.com/progrock.html>
qrp-labs.com
This kit is a simple minimalist controller for the Si5351A Synth kit (included with the ProgRock kit). It is intended as a programmable crystal replacement.



>>
>> It has a OCXO option, a box, a display(customizable), a GPS and could be probably fitted with a Raspberry Zero for a cheap NTP server too.
>>
>> Any advice?
>> Sorry if this has been already discussed here, didn't find any reference in the ML.
>>
>> Could it be compared to a Thunderbolt GPSO in terms of performance, how worse it could be?
>>
>> I just need a clean/self-calibrating 10MHz reference to tune HF radios ...seems good enough for the price.
>>
>> Giuseppe Marullo
>> IW2JWW - JN45RQ
>>
>>
>>
>> _______________________________________________
>> time-nuts mailing list -- time-***@febo.com
>> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
time-nuts Info Page - American Febo Enterprises<https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts>
www.febo.com
time-nuts is a low volume, high SNR list for the discussion of precise time and frequency measurement and related topics. To see the collection of prior postings to ...



>> and follow the instructions there.
>
> _______________________________________________
> time-nuts mailing list -- time-***@febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
time-nuts Info Page - American Febo Enterprises<https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts>
www.febo.com
time-nuts is a low volume, high SNR list for the discussion of precise time and frequency measurement and related topics. To see the collection of prior postings to ...



> and follow the instructions there.

_______________________________________________
time-nuts mailing list -- time-***@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
time-nuts Info Page - American Febo Enterprises<https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts>
www.febo.com
time-nuts is a low volume, high SNR list for the discussion of precise time and frequency measurement and related topics. To see the collection of prior postings to ...



and follow the instructions there.
_______________________________________________
time-nuts mailing list -- time-***@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
Attila Kinali
2016-10-23 15:52:57 UTC
Permalink
On Sun, 23 Oct 2016 15:32:33 +0200
Giuseppe Marullo <***@marullo.it> wrote:

> I am puzzled about what to do, still the total cost of it for a OXCO +
> GPS(unit with antenna) + control mcu is 67usd, I doubt I could find
> anything like this for a cheaper price new.

Yes, it's cheap for a kit, but it is not that cheap if you want to be cheap. :-)

You can get GPS modules for as low as $5 on ebay (these are new),
a uC board for another $10-30 (even cheaper on ebay) and a quite good
OCXO for $10-30, also from ebay. A few wires, a bit of programming and
you have an GPSDO that beats the progrock. So, by buying the right stuff
you can stay below $30 and have something that will get you a long way
for experimenting.

Just for the fun of it:

http://www.ebay.com/itm/STM32F030F4P6-ARM-CORTEX-M0-Core-Mini-System-Development-Board-5V-3-3V-/371769616187?hash=item568f32273b:g:seAAAOSwXeJYCx63
$1.40
http://www.ebay.com/itm/MCP4725-I2C-DAC-Breakout-Development-Board-12Bit-Resolution-/401209928223?hash=item5d69f9aa1f:g:j5gAAOSw34FVH5b1
$1
http://www.ebay.com/itm/Aircraft-Flight-Controller-w-Ublox-NEO-6M-GPS-Module-for-Arduino-APM2-/182318966076?hash=item2a730ea53c:g:QuoAAOSwOVpXc3K~
$5.04
http://www.ebay.com/itm/1-USED-ISOTEMP-OCXO-143-141-10-MHz-5V-SC-CUT-Square-Wave-Crystal-Oscillator-/331997554003?hash=item4d4c98a553:g:w~sAAOSwCGVX~g24
$16

Total cost: ~$25 including shipping and all but the OCXO are new.
You will need programmer for the uC board, if you don't have that, change
the uC board for an STM32F0DISCOVERY board:
http://eu.mouser.com/ProductDetail/STMicroelectronics/STM32F0DISCOVERY

Of course, any "real" GPSDO will beat this one by orders of magnitude
in phase noise and stability, but they are also much less fun to build :-)


Attila Kinali
--
Malek's Law:
Any simple idea will be worded in the most complicated way.
_______________________________________________
time-nuts mailing list -- time-***@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
Giuseppe Marullo
2016-10-23 23:05:24 UTC
Permalink
Hello Attila,

not cheap at that point, and I already have that ST board(I live few km
from ST headquarters, BTW)!.

Still licking my wounds from Eclipse-whatever chaintool, ouch, no way I
am going to mess with that again anytime soon.

I am not in the mood to start another endless project, way too many
unfinished stull in my drawers(as many others I guess).

I like the qrp-kit kit, but I will have a good look at eevb for the
"thunderbolt in disguise" and then I will decide.

Thanks.

Giuseppe Marullo

IW2JWW - JN45RQ




On 10/23/2016 5:52 PM, Attila Kinali wrote:
> On Sun, 23 Oct 2016 15:32:33 +0200
> Giuseppe Marullo <***@marullo.it> wrote:
>
>> I am puzzled about what to do, still the total cost of it for a OXCO +
>> GPS(unit with antenna) + control mcu is 67usd, I doubt I could find
>> anything like this for a cheaper price new.
> Yes, it's cheap for a kit, but it is not that cheap if you want to be cheap. :-)
>
> You can get GPS modules for as low as $5 on ebay (these are new),
> a uC board for another $10-30 (even cheaper on ebay) and a quite good
> OCXO for $10-30, also from ebay. A few wires, a bit of programming and
> you have an GPSDO that beats the progrock. So, by buying the right stuff
> you can stay below $30 and have something that will get you a long way
> for experimenting.
>
> Just for the fun of it:
>
> http://www.ebay.com/itm/STM32F030F4P6-ARM-CORTEX-M0-Core-Mini-System-Development-Board-5V-3-3V-/371769616187?hash=item568f32273b:g:seAAAOSwXeJYCx63
> $1.40
> http://www.ebay.com/itm/MCP4725-I2C-DAC-Breakout-Development-Board-12Bit-Resolution-/401209928223?hash=item5d69f9aa1f:g:j5gAAOSw34FVH5b1
> $1
> http://www.ebay.com/itm/Aircraft-Flight-Controller-w-Ublox-NEO-6M-GPS-Module-for-Arduino-APM2-/182318966076?hash=item2a730ea53c:g:QuoAAOSwOVpXc3K~
> $5.04
> http://www.ebay.com/itm/1-USED-ISOTEMP-OCXO-143-141-10-MHz-5V-SC-CUT-Square-Wave-Crystal-Oscillator-/331997554003?hash=item4d4c98a553:g:w~sAAOSwCGVX~g24
> $16
>
> Total cost: ~$25 including shipping and all but the OCXO are new.
> You will need programmer for the uC board, if you don't have that, change
> the uC board for an STM32F0DISCOVERY board:
> http://eu.mouser.com/ProductDetail/STMicroelectronics/STM32F0DISCOVERY
>
> Of course, any "real" GPSDO will beat this one by orders of magnitude
> in phase noise and stability, but they are also much less fun to build :-)
>
>
> Attila Kinali

_______________________________________________
time-nuts mailing list -- time-***@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
Giuseppe Marullo
2016-10-30 06:10:26 UTC
Permalink
I ended up buying a pre-cooked Trimble plus a missilehead-like GPS antenna:

http://www.ebay.it/itm/252162780444?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT
http://www.ebay.it/itm/262679152903?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

This should limit the chance it would be a DOA(well I hope at least), it
comes already boxed, has somewhat a wide power supply voltage range, no
pigtails to play with, and the antenna is new.

Now I just need to prepare the cable for the antenna, the mounting pole
and wait them to arrive through snail mail.

Many thanks to all but especially to Larry McDavid W6FUB that helped me
a lot to decide.

Now, while I wait...

1) I am reading the thread on EEVBlog(Thanks Bob and Bryan), (I have
like one month before I receive the unit so I could have spent more, I
admit) but I have several questions:

a) Is this a board or a puzzle? seems that brings reverse
engineering to a whole new level. 32 pages of forum posts looking for
missing parts...LOL

b) which is the difference between the Symmetrical and Trimble
unit? I am mostly interested in interfacing, like the ability to get
also NMEA sentences (if possible) and the ability to add the KOBB
display. In the thread there are a lot of information but really not
sure how much is common between the two. Only sure thing I have
understood seems that Trimble does not initiate a Survey at power on.

c) since I *may* like to use the GPS antenna also for the clock
kit(I WANT a DISPLAY!), I would like to build/buy a *simple* spitter.
Just a second output. I hope that a passive cheap schematic would do.
BTW, on which frequencies this unit receive data? Just 1575.42MHz? Would
it be possible to build a Wilkinson splitter?

d) still confused about the number of serial ports available, their
expected usage and voltage levels.

e) Which is the antenna signal level (dBm) that this unit require
to operate properly?


Giuseppe Marullo
IW2JWW - JN45RQ

On 10/24/2016 1:05 AM, Giuseppe Marullo wrote:
> Hello Attila,
>
> not cheap at that point, and I already have that ST board(I live few
> km from ST headquarters, BTW)!.
>
> Still licking my wounds from Eclipse-whatever chaintool, ouch, no way
> I am going to mess with that again anytime soon.
>
> I am not in the mood to start another endless project, way too many
> unfinished stull in my drawers(as many others I guess).
>
> I like the qrp-kit kit, but I will have a good look at eevb for the
> "thunderbolt in disguise" and then I will decide.
>
> Thanks.
>
> Giuseppe Marullo
>
> IW2JWW - JN45RQ
>
>
>
>
> On 10/23/2016 5:52 PM, Attila Kinali wrote:
>> On Sun, 23 Oct 2016 15:32:33 +0200
>> Giuseppe Marullo <***@marullo.it> wrote:
>>
>>> I am puzzled about what to do, still the total cost of it for a OXCO +
>>> GPS(unit with antenna) + control mcu is 67usd, I doubt I could find
>>> anything like this for a cheaper price new.
>> Yes, it's cheap for a kit, but it is not that cheap if you want to be
>> cheap. :-)
>>
>> You can get GPS modules for as low as $5 on ebay (these are new),
>> a uC board for another $10-30 (even cheaper on ebay) and a quite good
>> OCXO for $10-30, also from ebay. A few wires, a bit of programming and
>> you have an GPSDO that beats the progrock. So, by buying the right stuff
>> you can stay below $30 and have something that will get you a long way
>> for experimenting.
>>
>> Just for the fun of it:
>>
>> http://www.ebay.com/itm/STM32F030F4P6-ARM-CORTEX-M0-Core-Mini-System-Development-Board-5V-3-3V-/371769616187?hash=item568f32273b:g:seAAAOSwXeJYCx63
>>
>> $1.40
>> http://www.ebay.com/itm/MCP4725-I2C-DAC-Breakout-Development-Board-12Bit-Resolution-/401209928223?hash=item5d69f9aa1f:g:j5gAAOSw34FVH5b1
>>
>> $1
>> http://www.ebay.com/itm/Aircraft-Flight-Controller-w-Ublox-NEO-6M-GPS-Module-for-Arduino-APM2-/182318966076?hash=item2a730ea53c:g:QuoAAOSwOVpXc3K~
>>
>> $5.04
>> http://www.ebay.com/itm/1-USED-ISOTEMP-OCXO-143-141-10-MHz-5V-SC-CUT-Square-Wave-Crystal-Oscillator-/331997554003?hash=item4d4c98a553:g:w~sAAOSwCGVX~g24
>>
>> $16
>>
>> Total cost: ~$25 including shipping and all but the OCXO are new.
>> You will need programmer for the uC board, if you don't have that,
>> change
>> the uC board for an STM32F0DISCOVERY board:
>> http://eu.mouser.com/ProductDetail/STMicroelectronics/STM32F0DISCOVERY
>>
>> Of course, any "real" GPSDO will beat this one by orders of magnitude
>> in phase noise and stability, but they are also much less fun to
>> build :-)
>>
>>
>> Attila Kinali
>
> _______________________________________________
> time-nuts mailing list -- time-***@febo.com
> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.

_______________________________________________
time-nuts mailing list -- time-***@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
Bryan _
2016-10-30 09:57:55 UTC
Permalink
>>

<< e) Which is the antenna signal level (dBm) that this unit require
<<to operate properly?>>


The antenna you referenced should be fine. I would hazard to guess<g> that antennas a re a whole separate topic. The gain should be fine. What you need is a clear unobstructed view of the sky. That can be challenging depending on your location. Note that you will likely need some different connectors as the antenna looks to have a "N" type connector. You should also try and use cabling that I suitable and does not cause significant signal loss.


As for splitting remember that it is a active antenna and expects 5 volts so not sure if the Wilkinson splitter would work??. I would be interested as to what others have to say about splitting the antenna. Have read that a common television satellite antenna splitter commonly found on Ebay can be used, but the impedance may be 75 ohms and the connectors would have to be changed.


<< b) which is the difference between the Symmetrical and Trimble
<<unit? I am mostly interested in interfacing, like the ability to get
<<also NMEA sentences (if possible) and the ability to add the KOBB
<<display. In the thread there are a lot of information but really not
<<sure how much is common between the two. Only sure thing I have
<<understood seems that Trimble does not initiate a Survey at power on.


I had the Symmetricom so can't tell you much about the difference other that from what other posters have contributed they are very close to if not identical in many respects.Not having to complete another survey on power up is a definite plus on the Trimble, but I found that it can complete a survey on the Symmetricom quite quickly.


There is a number of serial ports on these boards. Looking at the fifth picture on the ebay link, at the top left corner next to the SMA connector just below R13 is a vertical row of holes. That is the main serial connection and it is at TTL levels. There is other serial connections available on a ribbon like connector at the end of the board. Posts on the EEVBlog show where and the pins on the ribbon connector and what they do. One poster on EEVblog probed the ribbon connector and identified the pins. http://tipok.org.ua/node/53. Some of the UART are high voltage, others TTL

[http://tipok.org.ua/sites/default/files/gps_rx_lores.jpg]<http://tipok.org.ua/node/53>

Trimble/Symmetricom UCCM GPS Receiver 50-pin connector ...<http://tipok.org.ua/node/53>
tipok.org.ua
Introduction. This page describes the pinouts of 50-pin connector, avaliable at "Trimble 57963-C" and "Symmetricom UCCM 089-03861-02" boards, which can be bought on Ebay.




Unfortunately they don't show the backside of the board in the Ebay link, but I strongly suspect as the main serial connection does not look populated by any wiring in the picture, they are tapping into the rx pin of the GPS receiver as the source for one of the RS232 connectors. This is a source of NMEA statements and is documented on the EEVblog. You can't send any commands put it does send out a continuous stream of useful NMEA commands that make it a ideal source for a DIY project to add a display. Once you receive your unit and connect it to your pc you will (should) see a stream of NMEA commands from one of the RS232 ports.


Hope this helps. I unfortunately toasted mine, and was contemplating about picking up another one.




-=Bryan=-


________________________________
From: time-nuts <time-nuts-***@febo.com> on behalf of Giuseppe Marullo <***@marullo.it>
Sent: October 29, 2016 11:10 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Has anybody checked this? GPSDO in kit

I ended up buying a pre-cooked Trimble plus a missilehead-like GPS antenna:

http://www.ebay.it/itm/252162780444?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT
Trimble GPS Receiver GPSDO 10MHz 1PPS GPS Disciplined Clock with rs232 port | eBay<http://www.ebay.it/itm/252162780444?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT>
www.ebay.it
Trimble GPS Receiver GPSDO 10MHz 1PPS GPS Disciplined Clock with rs232 port | | eBay!



http://www.ebay.it/itm/262679152903?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT
PCTEL GPS (L1) 26dB TIMING ANTENNA KIT GPS-TMG-26N W/ Mount Kit | eBay<http://www.ebay.it/itm/262679152903?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT>
www.ebay.it
PCTEL GPS (L1) 26dB TIMING ANTENNA KIT GPS-TMG-26N W/ Mount Kit | | eBay!




This should limit the chance it would be a DOA(well I hope at least), it
comes already boxed, has somewhat a wide power supply voltage range, no
pigtails to play with, and the antenna is new.

Now I just need to prepare the cable for the antenna, the mounting pole
and wait them to arrive through snail mail.

Many thanks to all but especially to Larry McDavid W6FUB that helped me
a lot to decide.

Now, while I wait...

1) I am reading the thread on EEVBlog(Thanks Bob and Bryan), (I have
like one month before I receive the unit so I could have spent more, I
admit) but I have several questions:

a) Is this a board or a puzzle? seems that brings reverse
engineering to a whole new level. 32 pages of forum posts looking for
missing parts...LOL

b) which is the difference between the Symmetrical and Trimble
unit? I am mostly interested in interfacing, like the ability to get
also NMEA sentences (if possible) and the ability to add the KOBB
display. In the thread there are a lot of information but really not
sure how much is common between the two. Only sure thing I have
understood seems that Trimble does not initiate a Survey at power on.

c) since I *may* like to use the GPS antenna also for the clock
kit(I WANT a DISPLAY!), I would like to build/buy a *simple* spitter.
Just a second output. I hope that a passive cheap schematic would do.
BTW, on which frequencies this unit receive data? Just 1575.42MHz? Would
it be possible to build a Wilkinson splitter?

d) still confused about the number of serial ports available, their
expected usage and voltage levels.

e) Which is the antenna signal level (dBm) that this unit require
to operate properly?


Giuseppe Marullo
IW2JWW - JN45RQ

On 10/24/2016 1:05 AM, Giuseppe Marullo wrote:
> Hello Attila,
>
> not cheap at that point, and I already have that ST board(I live few
> km from ST headquarters, BTW)!.
>
> Still licking my wounds from Eclipse-whatever chaintool, ouch, no way
> I am going to mess with that again anytime soon.
>
> I am not in the mood to start another endless project, way too many
> unfinished stull in my drawers(as many others I guess).
>
> I like the qrp-kit kit, but I will have a good look at eevb for the
> "thunderbolt in disguise" and then I will decide.
>
> Thanks.
>
> Giuseppe Marullo
>
> IW2JWW - JN45RQ
>
>
>
>
> On 10/23/2016 5:52 PM, Attila Kinali wrote:
>> On Sun, 23 Oct 2016 15:32:33 +0200
>> Giuseppe Marullo <***@marullo.it> wrote:
>>
>>> I am puzzled about what to do, still the total cost of it for a OXCO +
>>> GPS(unit with antenna) + control mcu is 67usd, I doubt I could find
>>> anything like this for a cheaper price new.
>> Yes, it's cheap for a kit, but it is not that cheap if you want to be
>> cheap. :-)
>>
>> You can get GPS modules for as low as $5 on ebay (these are new),
>> a uC board for another $10-30 (even cheaper on ebay) and a quite good
>> OCXO for $10-30, also from ebay. A few wires, a bit of programming and
>> you have an GPSDO that beats the progrock. So, by buying the right stuff
>> you can stay below $30 and have something that will get you a long way
>> for experimenting.
>>
>> Just for the fun of it:
>>
>> http://www.ebay.com/itm/STM32F030F4P6-ARM-CORTEX-M0-Core-Mini-System-Development-Board-5V-3-3V-/371769616187?hash=item568f32273b:g:seAAAOSwXeJYCx63
[http://i.ebayimg.com/images/i/371769616187-0-1/s-l1000.jpg]<http://www.ebay.com/itm/STM32F030F4P6-ARM-CORTEX-M0-Core-Mini-System-Development-Board-5V-3-3V-/371769616187?hash=item568f32273b:g:seAAAOSwXeJYCx63>

STM32F030F4P6 ARM CORTEX-M0 Core Mini System Development Board 5V/3.3V | eBay<http://www.ebay.com/itm/STM32F030F4P6-ARM-CORTEX-M0-Core-Mini-System-Development-Board-5V-3-3V-/371769616187?hash=item568f32273b:g:seAAAOSwXeJYCx63>
www.ebay.com
This board is a STM32F030F4P6 Minimum System Board(Cortex-M0). The target MCU is STM32F030F4P6 that is provided by ST. It is a ARM 32-bit Cortex?. -M0 CPU, frequency up to 48 MHz, high-speed embedded memories. | eBay!



>>
>> $1.40
>> http://www.ebay.com/itm/MCP4725-I2C-DAC-Breakout-Development-Board-12Bit-Resolution-/401209928223?hash=item5d69f9aa1f:g:j5gAAOSw34FVH5b1
[http://i.ebayimg.com/images/i/401209928223-0-1/s-l1000.jpg]<http://www.ebay.com/itm/MCP4725-I2C-DAC-Breakout-Development-Board-12Bit-Resolution-/401209928223?hash=item5d69f9aa1f:g:j5gAAOSw34FVH5b1>

MCP4725 I2C DAC Breakout Development Board 12Bit Resolution | eBay<http://www.ebay.com/itm/MCP4725-I2C-DAC-Breakout-Development-Board-12Bit-Resolution-/401209928223?hash=item5d69f9aa1f:g:j5gAAOSw34FVH5b1>
www.ebay.com
This version of the CJMCU-MCP4725 Breakout fixes a few issues with the board including the IC footprint, the I2C pinout, changes the overall board dimensions to better fit your projects, and a few more minor tweaks. | eBay!



>>
>> $1
>> http://www.ebay.com/itm/Aircraft-Flight-Controller-w-Ublox-NEO-6M-GPS-Module-for-Arduino-APM2-/182318966076?hash=item2a730ea53c:g:QuoAAOSwOVpXc3K~
[http://i.ebayimg.com/images/i/182318966076-0-1/s-l1000.jpg]<http://www.ebay.com/itm/Aircraft-Flight-Controller-w-Ublox-NEO-6M-GPS-Module-for-Arduino-APM2-/182318966076?hash=item2a730ea53c:g:QuoAAOSwOVpXc3K~>

Aircraft Flight Controller /w Ublox NEO-6M GPS Module for Arduino APM2 | eBay<http://www.ebay.com/itm/Aircraft-Flight-Controller-w-Ublox-NEO-6M-GPS-Module-for-Arduino-APM2-/182318966076?hash=item2a730ea53c:g:QuoAAOSwOVpXc3K~>
www.ebay.com
1pcs Ublox NEO-6M GPS Module Aircraft Flight Controller For Arduino MWC IMU APM2. Compatible with various flight controller module. Module with ceramic active antenna. Module size:23 x 30mm. We can also provide customized design and manufacture services. | eBay!



>>
>> $5.04
>> http://www.ebay.com/itm/1-USED-ISOTEMP-OCXO-143-141-10-MHz-5V-SC-CUT-Square-Wave-Crystal-Oscillator-/331997554003?hash=item4d4c98a553:g:w~sAAOSwCGVX~g24
[http://i.ebayimg.com/images/i/331997554003-0-1/s-l1000.jpg]<http://www.ebay.com/itm/1-USED-ISOTEMP-OCXO-143-141-10-MHz-5V-SC-CUT-Square-Wave-Crystal-Oscillator-/331997554003?hash=item4d4c98a553:g:w~sAAOSwCGVX~g24>

1×USED ISOTEMP OCXO 143-141 10 MHz 5V SC-CUT Square Wave Crystal Oscillator | eBay<http://www.ebay.com/itm/1-USED-ISOTEMP-OCXO-143-141-10-MHz-5V-SC-CUT-Square-Wave-Crystal-Oscillator-/331997554003?hash=item4d4c98a553:g:w~sAAOSwCGVX~g24>
www.ebay.com
Conditiion: Used. I promise I can give you satisfying solution. It is good for you and for me! I try my best to select good products to you and service you sincerely. Rate (item arrived). | eBay!



>>
>> $16
>>
>> Total cost: ~$25 including shipping and all but the OCXO are new.
>> You will need programmer for the uC board, if you don't have that,
>> change
>> the uC board for an STM32F0DISCOVERY board:
>> http://eu.mouser.com/ProductDetail/STMicroelectronics/STM32F0DISCOVERY
[http://eu.mouser.com/images/stmicroelectronics/images/64824_fig2.jpg]<http://eu.mouser.com/ProductDetail/STMicroelectronics/STM32F0DISCOVERY>

STM32F0DISCOVERY STMicroelectronics | Mouser<http://eu.mouser.com/ProductDetail/STMicroelectronics/STM32F0DISCOVERY>
eu.mouser.com
STM32F0DISCOVERY STMicroelectronics Development Boards & Kits - ARM Discovery F0 Board 32-Bit ARM Cortex M0 datasheet, inventory & pricing.



>>
>> Of course, any "real" GPSDO will beat this one by orders of magnitude
>> in phase noise and stability, but they are also much less fun to
>> build :-)
>>
>>
>> Attila Kinali
>
> _______________________________________________
> time-nuts mailing list -- time-***@febo.com
> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
time-nuts Info Page - American Febo Enterprises<https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts>
www.febo.com
time-nuts is a low volume, high SNR list for the discussion of precise time and frequency measurement and related topics. To see the collection of prior postings to ...



> and follow the instructions there.

_______________________________________________
time-nuts mailing list -- time-***@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
time-nuts Info Page - American Febo Enterprises<https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts>
www.febo.com
time-nuts is a low volume, high SNR list for the discussion of precise time and frequency measurement and related topics. To see the collection of prior postings to ...



and follow the instructions there.
_______________________________________________
time-nuts mailing list -- time-***@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
Giuseppe Marullo
2016-10-31 02:26:24 UTC
Permalink
> e) Which is the antenna signal level (dBm) that this unit require
> to operate properly?>>
>>The antenna you referenced should be fine. I would hazard to guess<g> that antennas a re a whole separate topic. The gain should be fine. What you need is a clear unobstructed view of the sky. I am pretty close to the window, with somewhat easy access to the roof. A 5m pole would pull out the antenna over the roof from the balcony(12m length total, worst case). No taller building around for several hundreds meters.
Having a more precise required signal level would help. SAT cables are mismatched but generally cheaper and able to play nice with cheap splitters, but to play safe I should stay with more expensive cable. LMR-400 sure original is a Tiffany item, here. Lot's of LMR-400 "equivalent" and not even cheap. Ouch.


>>As for splitting remember that it is a active antenna and expects 5
volts so not sure if the Wilkinson splitter would work??.
Since yesterday I was thinking Wilkinson were a brand of shaving blades!
Seems yes, according to this schematic:
http://electronics.stackexchange.com/questions/247256/gps-splitter-with-200ohm-dc-load-and-50ohm-rf-impedance-on-all-ports
This one takes into account sensing for antenna too, so I hope the
answer is yes.

>> I would be interested as to what others have to say about splitting
the antenna. Have read that a common television satellite antenna
splitter commonly found on Ebay can be used, but the impedance may be 75
ohms and the connectors would have to be changed.
If they work, it could be a cheap option, but I've always seen them with
F connectors, so it could be not worth it.

> b) which is the difference between the Symmetrical and Trimble
(...omissis...)
>understood seems that Trimble does not initiate a Survey at power on.
>>I had the Symmetricom so can't tell you much about the difference
other that from what other posters have contributed they are very close
to if not identical in many respects.Not having to complete another
survey on >>power up is a definite plus on the Trimble, but I found that
it can complete a survey on the Symmetricom quite quickly.
Ok, thanks.

>>There is a number of serial ports on these boards. Looking at the
fifth picture on the ebay link, at the top left corner next to the SMA
connector just below R13 is a vertical row of holes. That is the main
serial connection and >>it is at TTL levels. There is other serial
connections available on a ribbon like connector at the end of the
board. Posts on the EEVBlog show where and the pins on the ribbon
connector and what they do. One poster on >>EEVblog probed the ribbon
connector and identified the pins. http://tipok.org.ua/node/53. Some of
the UART are high voltage, others TTL
>>[http://tipok.org.ua/sites/default/files/gps_rx_lores.jpg]<http://tipok.org.ua/node/53>Trimble/Symmetricom UCCM GPS Receiver 50-pin connector ...<http://tipok.org.ua/node/53>
>>tipok.org.ua
>>Introduction. This page describes the pinouts of 50-pin connector,
avaliable at "Trimble 57963-C" and "Symmetricom UCCM 089-03861-02"
boards, which can be bought on Ebay.
>>Unfortunately they don't show the backside of the board in the Ebay
link, but I strongly suspect as the main serial connection does not look
populated by any wiring in the picture, they are tapping into the rx pin
of the GPS >>receiver as the source for one of the RS232 connectors.
This is a source of NMEA statements and is documented on the EEVblog.
I asked the seller to provide docs, he was quick to answer but still
nothing about the specific stuff the enclosure does. A Chinese would not
populate a connector for nothing, if it's there there should serve a
purpose.

>>You can't send any commands put it does send out a continuous stream
of useful NMEA commands that make it a ideal source for a DIY project to
add a display. Once you receive your unit and connect it to your pc you
will >>(should) see a stream of NMEA commands from one of the RS232 ports.
Let's wait and see what will come up. He said it is not NMEA, but TIPP,
well not exactly TIPP but similar (!??!!). My bad English strikes again...

>>Hope this helps. I unfortunately toasted mine, and was contemplating
about picking up another one.
Sorry to hear that. Hope you either fix or replace it.

Giuseppe Marullo
IW2JWW - jn45RQ

PS: I nevertheless bought the clock kit with a GPS antenna from
qrp-labs, with enclosure and GPS antenna but not the frequency
reference(yet). Once both will work I will nag you about how to easily
compare the two...


_______________________________________________
time-nuts mailing list -- time-***@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
Bryan _
2016-10-31 09:22:24 UTC
Permalink
Seller probably meant TSIP. This probably means he is using the end connector on the board and populating the RS232 connectors on the front of the unit with the various USART outputs that are available on the end connector. I note one of the RS232 connectors has a pin identified as 1pps and this is what is available from the end connector as well.


http://tipok.org.ua/node/53


NMEA like commands are available on the Symmetricom unit by tapping into a pin on the Furuno GPS receiver. I suspect the Trimble is the same, but the seller is not using this option (perhaps not available with a Trimble). I say "like" as the NMEA statements if I recall are missing the checksum. Not a big deal but most of the monitoring programs expect to see it for them to work. Although you can easily view the NMEA statements using a terminal program. There is a few PIC, Arduino projects out there that can take the NMEA statements and display on a LCD, GLCD. I am sure you probably saw a few on the EEVblog forum.


-=Bryan=-


________________________________
From: time-nuts <time-nuts-***@febo.com> on behalf of Giuseppe Marullo <***@marullo.it>
Sent: October 30, 2016 7:26 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Has anybody checked this? GPSDO in kit

> e) Which is the antenna signal level (dBm) that this unit require
> to operate properly?>>
>>The antenna you referenced should be fine. I would hazard to guess<g> that antennas a re a whole separate topic. The gain should be fine. What you need is a clear unobstructed view of the sky. I am pretty close to the window, with somewhat easy access to the roof. A 5m pole would pull out the antenna over the roof from the balcony(12m length total, worst case). No taller building around for several hundreds meters.
Having a more precise required signal level would help. SAT cables are mismatched but generally cheaper and able to play nice with cheap splitters, but to play safe I should stay with more expensive cable. LMR-400 sure original is a Tiffany item, here. Lot's of LMR-400 "equivalent" and not even cheap. Ouch.


>>As for splitting remember that it is a active antenna and expects 5
volts so not sure if the Wilkinson splitter would work??.
Since yesterday I was thinking Wilkinson were a brand of shaving blades!
Seems yes, according to this schematic:
http://electronics.stackexchange.com/questions/247256/gps-splitter-with-200ohm-dc-load-and-50ohm-rf-impedance-on-all-ports
[http://cdn.sstatic.net/Sites/electronics/img/apple-touch-***@2.png?v=7b89fddaa66b&a]<http://electronics.stackexchange.com/questions/247256/gps-splitter-with-200ohm-dc-load-and-50ohm-rf-impedance-on-all-ports>

GPS splitter with 200ohm DC load and 50ohm RF impedance on all ports<http://electronics.stackexchange.com/questions/247256/gps-splitter-with-200ohm-dc-load-and-50ohm-rf-impedance-on-all-ports>
electronics.stackexchange.com
How can the GPS400 signal splitter provide a \\$200~\\Omega\\$ DC load and \\$50~\\Omega\\$ RF load to GPS receivers on all four ports? Most GPS receiver modules require an active antenna. As a result,...



This one takes into account sensing for antenna too, so I hope the
answer is yes.

>> I would be interested as to what others have to say about splitting
the antenna. Have read that a common television satellite antenna
splitter commonly found on Ebay can be used, but the impedance may be 75
ohms and the connectors would have to be changed.
If they work, it could be a cheap option, but I've always seen them with
F connectors, so it could be not worth it.

> b) which is the difference between the Symmetrical and Trimble
(...omissis...)
>understood seems that Trimble does not initiate a Survey at power on.
>>I had the Symmetricom so can't tell you much about the difference
other that from what other posters have contributed they are very close
to if not identical in many respects.Not having to complete another
survey on >>power up is a definite plus on the Trimble, but I found that
it can complete a survey on the Symmetricom quite quickly.
Ok, thanks.

>>There is a number of serial ports on these boards. Looking at the
fifth picture on the ebay link, at the top left corner next to the SMA
connector just below R13 is a vertical row of holes. That is the main
serial connection and >>it is at TTL levels. There is other serial
connections available on a ribbon like connector at the end of the
board. Posts on the EEVBlog show where and the pins on the ribbon
connector and what they do. One poster on >>EEVblog probed the ribbon
connector and identified the pins. http://tipok.org.ua/node/53. Some of
[http://tipok.org.ua/sites/default/files/gps_rx_lores.jpg]<http://tipok.org.ua/node/53>

Trimble/Symmetricom UCCM GPS Receiver 50-pin connector ...<http://tipok.org.ua/node/53>
tipok.org.ua
Introduction. This page describes the pinouts of 50-pin connector, avaliable at "Trimble 57963-C" and "Symmetricom UCCM 089-03861-02" boards, which can be bought on Ebay.



the UART are high voltage, others TTL
>>[http://tipok.org.ua/sites/default/files/gps_rx_lores.jpg]<http://tipok.org.ua/node/53>Trimble/Symmetricom UCCM GPS Receiver 50-pin connector ...<http://tipok.org.ua/node/53>
[http://tipok.org.ua/sites/default/files/gps_rx_lores.jpg]<http://tipok.org.ua/node/53>

Trimble/Symmetricom UCCM GPS Receiver 50-pin connector ...<http://tipok.org.ua/node/53>
tipok.org.ua
Introduction. This page describes the pinouts of 50-pin connector, avaliable at "Trimble 57963-C" and "Symmetricom UCCM 089-03861-02" boards, which can be bought on Ebay.



>>tipok.org.ua
>>Introduction. This page describes the pinouts of 50-pin connector,
avaliable at "Trimble 57963-C" and "Symmetricom UCCM 089-03861-02"
boards, which can be bought on Ebay.
>>Unfortunately they don't show the backside of the board in the Ebay
link, but I strongly suspect as the main serial connection does not look
populated by any wiring in the picture, they are tapping into the rx pin
of the GPS >>receiver as the source for one of the RS232 connectors.
This is a source of NMEA statements and is documented on the EEVblog.
I asked the seller to provide docs, he was quick to answer but still
nothing about the specific stuff the enclosure does. A Chinese would not
populate a connector for nothing, if it's there there should serve a
purpose.

>>You can't send any commands put it does send out a continuous stream
of useful NMEA commands that make it a ideal source for a DIY project to
add a display. Once you receive your unit and connect it to your pc you
will >>(should) see a stream of NMEA commands from one of the RS232 ports.
Let's wait and see what will come up. He said it is not NMEA, but TIPP,
well not exactly TIPP but similar (!??!!). My bad English strikes again...

>>Hope this helps. I unfortunately toasted mine, and was contemplating
about picking up another one.
Sorry to hear that. Hope you either fix or replace it.

Giuseppe Marullo
IW2JWW - jn45RQ

PS: I nevertheless bought the clock kit with a GPS antenna from
qrp-labs, with enclosure and GPS antenna but not the frequency
reference(yet). Once both will work I will nag you about how to easily
compare the two...


_______________________________________________
time-nuts mailing list -- time-***@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
time-nuts Info Page - American Febo Enterprises<https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts>
www.febo.com
time-nuts is a low volume, high SNR list for the discussion of precise time and frequency measurement and related topics. To see the collection of prior postings to ...



and follow the instructions there.
_______________________________________________
time-nuts mailing list -- time-***@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
Bob Camp
2016-10-30 13:16:10 UTC
Permalink
Hi

Any pole mount outdoor antenna with a gain in the 20 to 30 db range should be
fine with any of these units. Cable loss can be an issue if it is getting the net
gain down below 10 db (antenna gain - cable loss). The frequency is 1.5 GHz
so a quick look at the standard tables should give you an idea what the loss
of any specific cable would be.

Trimble and Symmetricom made a number of “twin” units over the years. They
went into the same application, but did not function identically on the serial side.
The OEM apparently was expected to deal with two different interfaces. Things
like power in and timing signals out would be identical for the two designs.

Bob

> On Oct 30, 2016, at 2:10 AM, Giuseppe Marullo <***@marullo.it> wrote:
>
> I ended up buying a pre-cooked Trimble plus a missilehead-like GPS antenna:
>
> http://www.ebay.it/itm/252162780444?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT
> http://www.ebay.it/itm/262679152903?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT
>
> This should limit the chance it would be a DOA(well I hope at least), it comes already boxed, has somewhat a wide power supply voltage range, no pigtails to play with, and the antenna is new.
>
> Now I just need to prepare the cable for the antenna, the mounting pole and wait them to arrive through snail mail.
>
> Many thanks to all but especially to Larry McDavid W6FUB that helped me a lot to decide.
>
> Now, while I wait...
>
> 1) I am reading the thread on EEVBlog(Thanks Bob and Bryan), (I have like one month before I receive the unit so I could have spent more, I admit) but I have several questions:
>
> a) Is this a board or a puzzle? seems that brings reverse engineering to a whole new level. 32 pages of forum posts looking for missing parts...LOL
>
> b) which is the difference between the Symmetrical and Trimble unit? I am mostly interested in interfacing, like the ability to get also NMEA sentences (if possible) and the ability to add the KOBB display. In the thread there are a lot of information but really not sure how much is common between the two. Only sure thing I have understood seems that Trimble does not initiate a Survey at power on.
>
> c) since I *may* like to use the GPS antenna also for the clock kit(I WANT a DISPLAY!), I would like to build/buy a *simple* spitter. Just a second output. I hope that a passive cheap schematic would do. BTW, on which frequencies this unit receive data? Just 1575.42MHz? Would it be possible to build a Wilkinson splitter?
>
> d) still confused about the number of serial ports available, their expected usage and voltage levels.
>
> e) Which is the antenna signal level (dBm) that this unit require to operate properly?
>
>
> Giuseppe Marullo
> IW2JWW - JN45RQ
>
> On 10/24/2016 1:05 AM, Giuseppe Marullo wrote:
>> Hello Attila,
>>
>> not cheap at that point, and I already have that ST board(I live few km from ST headquarters, BTW)!.
>>
>> Still licking my wounds from Eclipse-whatever chaintool, ouch, no way I am going to mess with that again anytime soon.
>>
>> I am not in the mood to start another endless project, way too many unfinished stull in my drawers(as many others I guess).
>>
>> I like the qrp-kit kit, but I will have a good look at eevb for the "thunderbolt in disguise" and then I will decide.
>>
>> Thanks.
>>
>> Giuseppe Marullo
>>
>> IW2JWW - JN45RQ
>>
>>
>>
>>
>> On 10/23/2016 5:52 PM, Attila Kinali wrote:
>>> On Sun, 23 Oct 2016 15:32:33 +0200
>>> Giuseppe Marullo <***@marullo.it> wrote:
>>>
>>>> I am puzzled about what to do, still the total cost of it for a OXCO +
>>>> GPS(unit with antenna) + control mcu is 67usd, I doubt I could find
>>>> anything like this for a cheaper price new.
>>> Yes, it's cheap for a kit, but it is not that cheap if you want to be cheap. :-)
>>>
>>> You can get GPS modules for as low as $5 on ebay (these are new),
>>> a uC board for another $10-30 (even cheaper on ebay) and a quite good
>>> OCXO for $10-30, also from ebay. A few wires, a bit of programming and
>>> you have an GPSDO that beats the progrock. So, by buying the right stuff
>>> you can stay below $30 and have something that will get you a long way
>>> for experimenting.
>>>
>>> Just for the fun of it:
>>>
>>> http://www.ebay.com/itm/STM32F030F4P6-ARM-CORTEX-M0-Core-Mini-System-Development-Board-5V-3-3V-/371769616187?hash=item568f32273b:g:seAAAOSwXeJYCx63
>>> $1.40
>>> http://www.ebay.com/itm/MCP4725-I2C-DAC-Breakout-Development-Board-12Bit-Resolution-/401209928223?hash=item5d69f9aa1f:g:j5gAAOSw34FVH5b1
>>> $1
>>> http://www.ebay.com/itm/Aircraft-Flight-Controller-w-Ublox-NEO-6M-GPS-Module-for-Arduino-APM2-/182318966076?hash=item2a730ea53c:g:QuoAAOSwOVpXc3K~
>>> $5.04
>>> http://www.ebay.com/itm/1-USED-ISOTEMP-OCXO-143-141-10-MHz-5V-SC-CUT-Square-Wave-Crystal-Oscillator-/331997554003?hash=item4d4c98a553:g:w~sAAOSwCGVX~g24
>>> $16
>>>
>>> Total cost: ~$25 including shipping and all but the OCXO are new.
>>> You will need programmer for the uC board, if you don't have that, change
>>> the uC board for an STM32F0DISCOVERY board:
>>> http://eu.mouser.com/ProductDetail/STMicroelectronics/STM32F0DISCOVERY
>>>
>>> Of course, any "real" GPSDO will beat this one by orders of magnitude
>>> in phase noise and stability, but they are also much less fun to build :-)
>>>
>>>
>>> Attila Kinali
>>
>> _______________________________________________
>> time-nuts mailing list -- time-***@febo.com
>> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>> and follow the instructions there.
>
> _______________________________________________
> time-nuts mailing list -- time-***@febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.

_______________________________________________
time-nuts mailing list -- time-***@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
Giuseppe Marullo
2016-10-31 01:26:58 UTC
Permalink
>Any pole mount outdoor antenna with a gain in the 20 to 30 db range should be
>fine with any of these units. Cable loss can be an issue if it is getting the net
>gain down below 10 db (antenna gain - cable loss). The frequency is 1.5 GHz
Perfect, mine should have 3.5 + 26db. I will start with few meters of RG8X (or something similar I don't remember what I have) then I will use something better.


>Trimble and Symmetricom made a number of “twin” units over the years. They
>went into the same application, but did not function identically on the serial side.
>The OEM apparently was expected to deal with two different interfaces. Things
>like power in and timing signals out would be identical for the two designs.
Uhm, ok. Let's see what I will get.

thanks.

Giuseppe Marullo
IW2JWW - JN45RQ

_______________________________________________
time-nuts mailing list -- time-***@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
Mark Sims
2016-10-24 01:08:14 UTC
Permalink
For the money, those are excellent little GPSDOs... providing that it wasn't damaged while being salvaged. I got three different models in from 3 different sources and they all worked well. They are not nearly as tweakable as the Tbolt (nothing is) but they seem to get the job done. Supposedly the Symmetricom units have marginally better phase noise (YMMV), but I prefer the Trimble units for the sole reason that you can save the surveyed position and other settings in EEPROM and then they don't have do a survey each time you power them up.

And yes, the next release of Lady Heather works with them. The biggest annoyance is the time code message only comes out every two seconds so the clock displays tick on two second intervals. Lady Heather really want to run on a one-second update interval, so internally I fake the odd seconds so things like the alarm clock mode works properly.

I have the code for the next release pretty much completed and am currently (GASP!) writing some (EGAD!) documentation (OH THE HUMANITY!)

--------------------


> Only cheap alternative could be this one(already discussed here one year
ago):

http://www.ebay.com/itm/141734507722?_trksid=p2057872.m2749.l2649

Would this allow me to play as the "standard" ThunderBolt using the same
software? Any preferred model among
63090/73090/65256 "models"?
_______________________________________________
time-nuts mailing list -- time-***@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
Bryan _
2016-10-24 10:32:09 UTC
Permalink
Mark in your experience with these units, are the Trimble units adjustable in any way with regards to the oscillator such as damping, time constant etc. I had a Symmetricom unit but accidently fried it so could not experiment any further. I could not find any command that would allow any fine tuning of the OCXO. Wonder what the PullinRange means?


UCCM-P> ?
*IDN?
ALARm:HARDware?
ALARm:OPERation?
DIAGnostic:OUTPut ON|OFF
OUTPut:ACTive:ENABle
OUTPut:ACTive:DISable
OUTPut:ACTive:HOLDover:DURation:THReshold <seconds>
OUTPut:ACTive:HOLDover:DURation:THReshold?
OUTPut:INACTive
OUTPut:INACTive?
OUTPut:STATe?
SYNChronization:HOLDover:DURation:STATus:THReshold <seconds>
SYSTem:PRESet
SYNChronization:TFOMerit?
LED:GPSLock?
SYNChronization:FFOMerit?
GPS:POSition N or S,<deg>,<min>,<sec>,E or W,<deg>,<min>,<sec>,<height>
GPS:POSition?
GPS:POSition:HOLD:LAST?
GPS:REFerence:ADELay <numeric value>
GPS:REFerence:ADELay?
GPS:SATellite:TRACking:COUNt?
GPS:SATellite:TRACking?
DIAGnostic:ROSCillator:EFControl:RELative?
SYNChronization:TINTerval?
DIAGnostic:LOG:READ:ALL?
DIAGnostic:LOG:CLEar
SYSTem:PON
OUTPut:MODE?
SYSTem:STATus?
SYSTem:COMMunication:SERial1:BAUD 9600|19200|38400|57600
SYSTem:COMMunication:SERial1:BAUD?
SYSTem:COMMunication:SERial1:PRESet
SYSTem:COMMunication:SERial2:BAUD 9600|19200|38400|57600
SYSTem:COMMunication:SERial2:BAUD?
SYSTem:COMMunication:SERial2:PRESet
OUTPut:STANby:THReshold <seconds>
changeSN
SYNChronization:REFerence:ENABLE LINK|GPS
SYNChronization:REFerence:DISABLE LINK|GPS
SYNChronization:REFerence:ENABLE?
STATus
POSSTATus
TOD EN|DI
TIME:STRing?
REFerence:TYPE GPS|LINK
REFerence:TYPE?
PULLINRANGE 0|1|2|...|254|255
PULLINRNAGE?
DIAGnostic:LOOP?
DIAGnostic:ROSCillator:EFControl:DATA GPS|<value>
DIAGnostic:ROSCillator:EFControl:DATA?
OUTPut:TP:SELection PP1S|PP2S
OUTPut:TP:SELection?
GPSystem:SATellite:TRACking:EMANgle <degrees>
GPSystem:SATellite:TRACking:EMANgle?
DIAGnostic:TCODe:STATus:AMASk
DIAGnostic:TCODe:STATus:OMASk
DIAGnostic:TCODe:ERRor:AMASk
DIAGnostic:TCODe:ERRor:OMASk
DIAGnostic:HOLDover:DELay
DIAGnostic:HOLDover:DELay?
GPS:SATellite:TRACking:IGNore <PRN>, ...,<PRN>
GPS:SATellite:TRACking:IGNore?
GPS:SATellite:TRACking:INCLude <PRN>, ...,<PRN>
GPS:SATellite:TRACking:INCLude?
GPS:SATellite:TRACking:<select>:ALL
Command Complete
UCCM-P >


p.s. Looking forward to the latest Lady Heather release.


-=Bryan=-


________________________________
From: time-nuts <time-nuts-***@febo.com> on behalf of Mark Sims <***@hotmail.com>
Sent: October 23, 2016 6:08 PM
To: time-***@febo.com
Subject: [time-nuts] Has anybody checked this? GPSDO in kit

For the money, those are excellent little GPSDOs... providing that it wasn't damaged while being salvaged. I got three different models in from 3 different sources and they all worked well. They are not nearly as tweakable as the Tbolt (nothing is) but they seem to get the job done. Supposedly the Symmetricom units have marginally better phase noise (YMMV), but I prefer the Trimble units for the sole reason that you can save the surveyed position and other settings in EEPROM and then they don't have do a survey each time you power them up.

And yes, the next release of Lady Heather works with them. The biggest annoyance is the time code message only comes out every two seconds so the clock displays tick on two second intervals. Lady Heather really want to run on a one-second update interval, so internally I fake the odd seconds so things like the alarm clock mode works properly.

I have the code for the next release pretty much completed and am currently (GASP!) writing some (EGAD!) documentation (OH THE HUMANITY!)

--------------------


> Only cheap alternative could be this one(already discussed here one year
ago):

http://www.ebay.com/itm/141734507722?_trksid=p2057872.m2749.l2649
[http://i.ebayimg.com/images/i/141734507722-0-1/s-l1000.jpg]<http://www.ebay.com/itm/141734507722?_trksid=p2057872.m2749.l2649>

Used Tested 10MHz Trimble 63090/73090/65256 GPS board OCXO | eBay<http://www.ebay.com/itm/141734507722?_trksid=p2057872.m2749.l2649>
www.ebay.com
Note : this item is used ,but Good quality. | eBay!




Would this allow me to play as the "standard" ThunderBolt using the same
software? Any preferred model among
63090/73090/65256 "models"?
_______________________________________________
time-nuts mailing list -- time-***@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
time-nuts Info Page - American Febo Enterprises<https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts>
www.febo.com
time-nuts is a low volume, high SNR list for the discussion of precise time and frequency measurement and related topics. To see the collection of prior postings to ...



and follow the instructions there.
_______________________________________________
time-nuts mailing list -- time-***@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
Mark Sims
2016-10-30 17:48:55 UTC
Permalink
No, the 4 pin connector is at RS-232 levels. It connects to an RS-232 level converter chip. These "UCCM" devices speak SCPI at 57600,8,N,1 I have Lady Heather talking to them (soon to be released, I promise). I have tested it with four different firmware versions (all have some slight differences).

Most of the NMEA data sent from the receiver is proprietary Furuno commands. KO4BB.COM has a manual for the receiver...

------------------

Looking at the fifth picture on the ebay link, at the top left corner next to the SMA connector just below R13 is a vertical row of holes. That is the main serial connection and it is at TTL levels.
_______________________________________________
time-nuts mailing list -- time-***@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
Bryan _
2016-10-30 20:44:32 UTC
Permalink
Yes sorry, you are right it is at RS232 levels.


-=Bryan=-


________________________________
From: time-nuts <time-nuts-***@febo.com> on behalf of Mark Sims <***@hotmail.com>
Sent: October 30, 2016 10:48 AM
To: time-***@febo.com
Subject: [time-nuts] Has anybody checked this? GPSDO in kit

No, the 4 pin connector is at RS-232 levels. It connects to an RS-232 level converter chip. These "UCCM" devices speak SCPI at 57600,8,N,1 I have Lady Heather talking to them (soon to be released, I promise). I have tested it with four different firmware versions (all have some slight differences).

Most of the NMEA data sent from the receiver is proprietary Furuno commands. KO4BB.COM has a manual for the receiver...

------------------

Looking at the fifth picture on the ebay link, at the top left corner next to the SMA connector just below R13 is a vertical row of holes. That is the main serial connection and it is at TTL levels.
_______________________________________________
time-nuts mailing list -- time-***@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
time-nuts Info Page - American Febo Enterprises<https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts>
www.febo.com
time-nuts is a low volume, high SNR list for the discussion of precise time and frequency measurement and related topics. To see the collection of prior postings to ...



and follow the instructions there.
_______________________________________________
time-nuts mailing list -- time-***@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
Loading...