Discussion:
If there a FAQ
Add Reply
Chris Albertson
2010-11-29 04:26:18 UTC
Reply
Permalink
Raw Message
I'm new to this list. Before I ask a lot of questions maybe someone
can point me at some reading material.

I've decided I want a decent frequency reference for normal ham radio
stuff like calibrating test equipment, testing oscillators for
stability and so on.
I figure at first I'll start with something simple. I'll build
something around a TXCO chip and I'll build a single purpose WWV
receiver. Later I'll
buy a GPS receiver that has the 1PPS feature and get a better local
double oven osc from HP.

First question is a source of parts. Where to get the TXCO?, Is
there a preferred design for WWV receiver, What low cost GPSes should
I look at?

Pointers to reading material would be great.


Thanks.

Chris Albertson
Redondo Beach, California
J. Forster
2010-11-29 04:41:06 UTC
Reply
Permalink
Raw Message
WWV is not a very good option. The signal fades a lot and has HF noise
issues unless you have a really good location within ground wave. Carrier
tracking is likely hard, which means you have to deal with the 1 PPS pips.

I've used a digital averaging scope, triggered by the 1 PPS from my local
standard to trigger the scope display and watched the pips "walk" and
adjusted things, but it's a PITA.

You might want to think about WWVB at 60 KHz.

You can probably pick up a fairly good GPS and oscillator for roughly the
same price.

FWIW,

-John

=============


> I'm new to this list. Before I ask a lot of questions maybe someone
> can point me at some reading material.
>
> I've decided I want a decent frequency reference for normal ham radio
> stuff like calibrating test equipment, testing oscillators for
> stability and so on.
> I figure at first I'll start with something simple. I'll build
> something around a TXCO chip and I'll build a single purpose WWV
> receiver. Later I'll
> buy a GPS receiver that has the 1PPS feature and get a better local
> double oven osc from HP.
>
> First question is a source of parts. Where to get the TXCO?, Is
> there a preferred design for WWV receiver, What low cost GPSes should
> I look at?
>
> Pointers to reading material would be great.
>
>
> Thanks.
>
> Chris Albertson
> Redondo Beach, California
>
> _______________________________________________
> time-nuts mailing list -- time-nuts-***@public.gmane.org
> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>
>
Chris Albertson
2010-11-29 05:41:42 UTC
Reply
Permalink
Raw Message
WWV at 10MHz is not bad at all. My current "system" is a cheap
$0.75 10Mhz crystal tuned with a screwdriver on a veritable trimmer
capacitor. I know I can zero-beat it by ear and get within a couple Hz
out of 10MHz. That is better then 1E-6 simply by hand, ear and screwdriver.
No computer.

The trouble with a 60Khz signal is that a two cycle error gives
a 1 in 30K error,

I'm just looking to use it as a frequency standard, not caring at all about the
data they transmit

I figure my first upgrade is to replace the crystal with a temperature
compensated oscilator chip. Now to go find one.

--
=====
Chris Albertson
Redondo Beach, California
Bill Hawkins
2010-11-29 06:56:57 UTC
Reply
Permalink
Raw Message
Chris,

If you are familiar with vacuum tube stuff, I have a basket-case
Beckman 905 WWV receiver that you can have for shipping. The radio
was discarded because the 6AQ5 coupling capacitor got leaky and
caused smoke to be released from the power transformer, which is
otherwise OK. It was then sprayed with a fire extinguisher, which
ruined the speaker but didn't get past the front panel.

The 905 is a five channel crystal controlled dual conversion
receiver. Information is available on the web. It's in a basket
because I never got around to repairing it, after taking it apart.

Actually, if you have a good communication receiver, you have all
you need to set a 10 MHz crystal to 1E-8, if the adjustment has any
stability. That's a ten second beat rate. Then you need to filter
out the temperature variations, or fool around with NPO caps to
compensate for temperature variations.

Well maybe 1E-7, which is normal for WWV over the Rockies (sky-
wave).

Bill Hawkins



-----Original Message-----
From: time-nuts-bounces-***@public.gmane.org [mailto:time-nuts-bounces-***@public.gmane.org] On
Behalf Of Chris Albertson
Sent: Sunday, November 28, 2010 11:42 PM
To: jfor-***@public.gmane.org; Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] If there a FAQ

WWV at 10MHz is not bad at all. My current "system" is a cheap
$0.75 10Mhz crystal tuned with a screwdriver on a veritable trimmer
capacitor. I know I can zero-beat it by ear and get within a couple Hz
out of 10MHz. That is better then 1E-6 simply by hand, ear and screwdriver.
No computer.

The trouble with a 60Khz signal is that a two cycle error gives
a 1 in 30K error,

I'm just looking to use it as a frequency standard, not caring at all about
the
data they transmit

I figure my first upgrade is to replace the crystal with a temperature
compensated oscilator chip. Now to go find one.

--
=====
Chris Albertson
Redondo Beach, California
jimlux
2010-11-29 06:10:49 UTC
Reply
Permalink
Raw Message
Chris Albertson wrote:
> I'm new to this list. Before I ask a lot of questions maybe someone
> can point me at some reading material.

There's a great presentation from John Vig on the web..
The Ap note from HP on time and frequency is also good.


>
>
>
> First question is a source of parts. Where to get the TXCO?, Is
> there a preferred design for WWV receiver, What low cost GPSes should
> I look at?

OCXO's with good performance (as in low phase noise and decent Allan
deviation performance) are available on the usual surplus sources for
under $100, or even brand new for a few hundred bucks.

A good all-in-one package is something like a Thunderbolt
Hal Murray
2010-11-29 08:31:13 UTC
Reply
Permalink
Raw Message
> I know I can zero-beat it by ear and get within a couple Hz out of 10MHz.
> That is better then 1E-6 simply by hand, ear and screwdriver. No computer.

How do you get down to "a couple Hz"? I thought most (young?) ears dropped
out at about 20 Hz and I expect lots of radios chop off more than that just
to get rid of noise.

Can you center the screw between two I-hear-it spots?


> I figure my first upgrade is to replace the crystal with a temperature
> compensated oscilator chip. Now to go find one.

Don't get too focused on TCXOs. You are just as likely to find a low cost
OCXO.

While you are looking, keep an eye open for a TBolt or Z3801A. (or one of
the Z38xxA variations) If you find one at a reasonable price, they have an
incredible price/performance ratio. If you hang around here for long, you
will probably get one anyway. Unless you like the sort of fiddling you have
described, getting one now will save you a lot of time/effort.





--
These are my opinions, not necessarily my employer's. I hate spam.
Charles P. Steinmetz
2010-11-29 10:44:46 UTC
Reply
Permalink
Raw Message
Hal wrote:

>How do you get down to "a couple Hz"? I thought most (young?) ears dropped
>out at about 20 Hz and I expect lots of radios chop off more than that just
>to get rid of noise.

Beating of the received carrier and the oscillator being calibrated
results in full or partial cancellation of the composite carrier --
in effect, a locally-generated carrier fade and augmentation. You
hear the band noise and sideband distortion rise and fall as the
composite carrier falls and rises. Easy enough to hear beats a
minute long or more if band conditions are decent and you have the
oscillator injection level reasonably matched to the received carrier
level (though not so easy to quantify precisely by ear due to the
difficulty of identifying the exact minima or maxima).

Best regards,

Charles
Alan Melia
2010-11-29 11:11:24 UTC
Reply
Permalink
Raw Message
Oh Dear Hal how the old skills are lost when everything comes with digits on
it :-))
You put the BFO on and you do a 3 signal beat, which can be set to 0.1 Hz
quite easily by listening to the "swell". This is 1 in 10^8 at 10MHz !! Ah I
am showing my age again :-))
Alan G3NYK

----- Original Message -----
From: "Hal Murray" <hmurray-8cQiHa/C+6Go9G/***@public.gmane.org>
To: "Discussion of precise time and frequency measurement"
<time-nuts-***@public.gmane.org>
Sent: Monday, November 29, 2010 8:31 AM
Subject: Re: [time-nuts] If there a FAQ


>
> > I know I can zero-beat it by ear and get within a couple Hz out of
10MHz.
> > That is better then 1E-6 simply by hand, ear and screwdriver. No
computer.
>
> How do you get down to "a couple Hz"? I thought most (young?) ears
dropped
> out at about 20 Hz and I expect lots of radios chop off more than that
just
> to get rid of noise.
>
> Can you center the screw between two I-hear-it spots?
>
>
> > I figure my first upgrade is to replace the crystal with a temperature
> > compensated oscilator chip. Now to go find one.
>
> Don't get too focused on TCXOs. You are just as likely to find a low cost
> OCXO.
>
> While you are looking, keep an eye open for a TBolt or Z3801A. (or one of
> the Z38xxA variations) If you find one at a reasonable price, they have
an
> incredible price/performance ratio. If you hang around here for long, you
> will probably get one anyway. Unless you like the sort of fiddling you
have
> described, getting one now will save you a lot of time/effort.
>
>
>
>
>
> --
> These are my opinions, not necessarily my employer's. I hate spam.
>
>
>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts-***@public.gmane.org
> To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
jmfranke
2010-11-29 14:26:49 UTC
Reply
Permalink
Raw Message
Accurate Zero Beating, another perspective.
When trimming an oscillator so it or one of its harmonics zero beats with
WWV or other standard frequency transmission, much comment has been made
over the ability to approach true zero beat. When the harmonic is directly
zero beat, the stated accuracy is generally in the 1-5Hz range. There is a
technique that allows one to repeatedly zero beat to a much higher accuracy.
The method is called the "Three-Oscillator Method" and dates back to the
1930's, or earlier. The earliest discussion I have found was on page 47 of
Bulletin 10, "Frequency Measurements at Radio Frequencies," published by the
General Radio Company in February 1933. The bulletin states that the
"method has been in use for a number of years." The technique is also
presented in sections II and XII of the 1956 Technical Manual (TM11-2665)
for the AN/URM-18 Frequency Calibrator Set, the military version of the
General Radio Type 1100-A Frequency Standard. More recently, Alan Melia,
G3NYK, reports an accuracy of 0.1 Hertz using the same technique,
http://www.alan.melia.btinternet.co.uk/freqmeas.htm .
The three oscillators are the standard, the unknown, and either another
lesser accuracy oscillator or a receiver BFO. The AN/URM-18 and the General
Radio 1100-A frequency standards utilize regenerative receivers. Using
reception of WWV as an example; in normal practice the unknown or a harmonic
of the unknown is adjusted to zero beat with WWV by injecting a sample of
the unknown source into the antenna of an AM receiver tuned to one of the
WWV transmissions. As the unknown is trimmed or adjusted to match WWV, a
beat frequency will be heard that approaches 0 Hz or zero beat with the WWV
transmission. Unfortunately, the audio bandpass of the receiver and the
observer's ear limit hearing a beat frequency much below ten Hz. It is
possible to reach closer beat frequencies by listening to the background
noise wax and wane, but the results are not readily repeatable. Now, a
third source is introduced when the receiver BFO is turned on or the
regenerative receiver is adjusted to oscillate. With the unknown source
temporarily disconnected, the receiver is tuned to give a nominal 1 kHz beat
frequency while receiving the WWV transmission. When the unknown source is
once again added, the 1 kHz beat will wax and wane at a rate equal to the
beat between the unknown source and the WWV transmission. Changing the BFO
or receiver tuning only changes the frequency of the tone that waxes and
wanes. The waxing and waning rate is determined solely by the beat between
the WWV transmission and the unknown source. It is now easy to reliably
adjust the unknown, or its harmonic, to within a fraction of a Hertz of the
WWV transmission.

John M. Franke WA4WDL

--------------------------------------------------
From: "Hal Murray" <hmurray-8cQiHa/C+6Go9G/***@public.gmane.org>
Sent: Monday, November 29, 2010 3:31 AM
To: "Discussion of precise time and frequency measurement"
<time-nuts-***@public.gmane.org>
Subject: Re: [time-nuts] If there a FAQ

>
>> I know I can zero-beat it by ear and get within a couple Hz out of
>> 10MHz.
>> That is better then 1E-6 simply by hand, ear and screwdriver. No
>> computer.
>
> How do you get down to "a couple Hz"? I thought most (young?) ears
> dropped
> out at about 20 Hz and I expect lots of radios chop off more than that
> just
> to get rid of noise.
>
> Can you center the screw between two I-hear-it spots?
>
>
>> I figure my first upgrade is to replace the crystal with a temperature
>> compensated oscilator chip. Now to go find one.
>
> Don't get too focused on TCXOs. You are just as likely to find a low cost
> OCXO.
>
> While you are looking, keep an eye open for a TBolt or Z3801A. (or one of
> the Z38xxA variations) If you find one at a reasonable price, they have
> an
> incredible price/performance ratio. If you hang around here for long, you
> will probably get one anyway. Unless you like the sort of fiddling you
> have
> described, getting one now will save you a lot of time/effort.
>
>
>
>
>
> --
> These are my opinions, not necessarily my employer's. I hate spam.
>
>
>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts-***@public.gmane.org
> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>
jimlux
2010-11-29 14:51:46 UTC
Reply
Permalink
Raw Message
jmfranke wrote:
> Accurate Zero Beating, another perspective.
><snip>

The waxing and waning rate is determined solely by the
> beat between the WWV transmission and the unknown source. It is now
> easy to reliably adjust the unknown, or its harmonic, to within a
> fraction of a Hertz of the WWV transmission.
>


if one has a voltmeter (or total power detector, like your ear), hearing
low frequency beats at sub-1Hz is easy.. (anyone who has tuned an
instrument by ear, or sat in a plane with poorly synchronized engines
will know this)

consider the sum of two sinusoids cos(1.01*2pi* t) + cos (2*pi*t)...

when the two are in phase (say, at t=0), the amplitude is 2 (RMS =
1.414).. but, when they are just out of phase (say, at t = 50), the
amplitude of the sum is zero, and then, at around t= 100, they're in
phase again and the amplitude is back to 2.

This is different than the "saturated mixer" sort of thing, where you
get an explicit sum and difference.

More like spring and neap tides.
Mike Naruta AA8K
2010-11-29 18:53:48 UTC
Reply
Permalink
Raw Message
Have you ever tried humming while watching a propeller?
The strobe effect is fascinating.

My flight instructor thought that I was crazy until he tried it.


Mike - AA8K


On 11/29/2010 09:51 AM, jimlux wrote:
>
> if one has a voltmeter (or total power detector, like your ear), hearing
> low frequency beats at sub-1Hz is easy.. (anyone who has tuned an
> instrument by ear, or sat in a plane with poorly synchronized engines
> will know this)
>
William H. Fite
2010-11-30 16:42:27 UTC
Reply
Permalink
Raw Message
Something my primary flight instructor pointed out to me years...yea,
decades ago. Haven't thought about it since then.

I expect you can do the same thing with an electric fan.
Bill



On Mon, Nov 29, 2010 at 1:53 PM, Mike Naruta AA8K <aa8k-***@public.gmane.org> wrote:

>
> Have you ever tried humming while watching a propeller?
> The strobe effect is fascinating.
>
> My flight instructor thought that I was crazy until he tried it.
>
>
> Mike - AA8K
>
>
>
> On 11/29/2010 09:51 AM, jimlux wrote:
>
>>
>> if one has a voltmeter (or total power detector, like your ear), hearing
>> low frequency beats at sub-1Hz is easy.. (anyone who has tuned an
>> instrument by ear, or sat in a plane with poorly synchronized engines
>> will know this)
>>
>>
> _______________________________________________
> time-nuts mailing list -- time-nuts-***@public.gmane.org
> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>
Mark J. Blair
2010-11-30 18:53:33 UTC
Reply
Permalink
Raw Message
On Nov 30, 2010, at 8:42 AM, William H. Fite wrote:
> I expect you can do the same thing with an electric fan.

Or by chewing something crunchy (like ice) while watching a raster-scanned (CRT) television.




--
Mark J. Blair, NF6X <nf6x-/***@public.gmane.org>
Web page: http://www.nf6x.net/
GnuPG public key available from my web page.
Chris Albertson
2010-11-29 17:41:29 UTC
Reply
Permalink
Raw Message
You don't need hearing ability for low pitches. As the beat frequency
gets lows it
it sounds like the volume is being pulsed. Like something is playing
with the volume
knob once per second.

It is the same say you tune a musical instrument. You listen for
volume modulation.
The two pitches either add constructively or destructively. With good ears and
practice you can match to less then one Hz. But "anyone" can get 2
Hz. If you
are matching 10MHz oscillators that means 1E-7 just by ear.

Yes the best plan is to place the screw mid point because at beat match there is
literally no sound

On Mon, Nov 29, 2010 at 12:31 AM, Hal Murray <hmurray-8cQiHa/C+6Go9G/***@public.gmane.org> wrote:
>
>> I know I can zero-beat  it by ear and get within a couple Hz out of 10MHz.
>> That is better then 1E-6 simply by hand, ear and screwdriver. No computer.
>
> How do you get down to "a couple Hz"?  I thought most (young?) ears dropped
> out at about 20 Hz and I expect lots of radios chop off more than that just
> to get rid of noise.
>
> Can you center the screw between two I-hear-it spots?


--
=====
Chris Albertson
Redondo Beach, California
Hal Murray
2010-11-29 09:06:31 UTC
Reply
Permalink
Raw Message
albertson.chris-***@public.gmane.org said:
> What low cost GPSes should I look at?

These days, most low cost GPS units are USB, but those don't have a PPS
signal.

You may be able to find the PPS signal on the module in there if you take it
apart.

These are the only low cost ones I know of with PPS. Both require chopping
off the connector they ship with and wiring up to an RS-232 connector and
providing power.

Garmin GPS 18x LVC:
https://buy.garmin.com/shop/shop.do?pID=27594
http://www.provantage.com/garmin-010-00321-36~7GRMO006.htm
Garmin has 3 versions of the GPS 18x. Be sure to get the LVC.

GlobalSat MR-350:
http://www.usglobalsat.com/p-58-mr-350p-bulkhead.aspx

If you find any more inexpensive ones with PPS, please let me know.


Those are hockey-puck, or mouse units, a clean package with a 15 ft cord.

You can also find bare modules. Some of them require an antenna. Some have an antenna built in. Here are some examples. Google will probably find many more.
http://www.sparkfun.com/categories/4
http://www.sparkfun.com/tutorials/127

Some of the older modules have a 10 KHz output. That makes building an analog PLL reasonable. Google for Jupiter.




--
These are my opinions, not necessarily my employer's. I hate spam.
s***@public.gmane.org
2010-11-30 13:33:36 UTC
Reply
Permalink
Raw Message
Don't get hung up around the idea that a TCXO is always better than a plain XO. They are typically designed the reduce the effects of large temperature variations, but a typical OCXO will be much better when your temperature variations are limited, like at home.

Also, a TCXO will usually have lower power consumption and be smaller than an OCXO, but then again, at home, you probably don't care about either.

Just find any HP 10811, by itself or inside an instrument (you can often buy a whole instrument with an internal 10811 cheaper than you can buy the 10811 by itself)

Didier

Sent from my Verizon Wireless BlackBerry

-----Original Message-----
From: Chris Albertson <albertson.chris-***@public.gmane.org>
Sender: time-nuts-bounces-***@public.gmane.org
Date: Sun, 28 Nov 2010 20:26:18
To: Discussion of precise time and frequency measurement<time-nuts-***@public.gmane.org>
Reply-To: Discussion of precise time and frequency measurement
<time-nuts-***@public.gmane.org>
Subject: [time-nuts] If there a FAQ

I'm new to this list. Before I ask a lot of questions maybe someone
can point me at some reading material.

I've decided I want a decent frequency reference for normal ham radio
stuff like calibrating test equipment, testing oscillators for
stability and so on.
I figure at first I'll start with something simple. I'll build
something around a TXCO chip and I'll build a single purpose WWV
receiver. Later I'll
buy a GPS receiver that has the 1PPS feature and get a better local
double oven osc from HP.

First question is a source of parts. Where to get the TXCO?, Is
there a preferred design for WWV receiver, What low cost GPSes should
I look at?

Pointers to reading material would be great.


Thanks.

Chris Albertson
Redondo Beach, California

_______________________________________________
time-nuts mailing list -- time-nuts-***@public.gmane.org
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
Chris Albertson
2010-11-30 19:29:10 UTC
Reply
Permalink
Raw Message
On Tue, Nov 30, 2010 at 5:33 AM, <shalimr9-***@public.gmane.org> wrote:

> Just find any HP 10811, by itself or inside an instrument (you can often buy a whole instrument with an internal 10811 cheaper than you can buy the 10811 by itself).....

What HP instruments would have the HP 10811 inside?

--
=====
Chris Albertson
Redondo Beach, California
J. L. Trantham, M. D.
2010-11-30 20:29:04 UTC
Reply
Permalink
Raw Message
My favorite has been the 5334B with Option 010.

Joe

-----Original Message-----
From: time-nuts-bounces-***@public.gmane.org [mailto:time-nuts-bounces-***@public.gmane.org]On
Behalf Of Chris Albertson
Sent: Tuesday, November 30, 2010 1:29 PM
To: shalimr9-***@public.gmane.org; Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] If there a FAQ

On Tue, Nov 30, 2010 at 5:33 AM, <shalimr9-***@public.gmane.org> wrote:

> Just find any HP 10811, by itself or inside an instrument (you can often
buy a whole instrument with an internal 10811 cheaper than you can buy the
10811 by itself).....

What HP instruments would have the HP 10811 inside?

--
=====
Chris Albertson
Redondo Beach, California

_______________________________________________
time-nuts mailing list -- time-nuts-***@public.gmane.org
To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
-----
No virus found in this message.
Checked by AVG - www.avg.com
Version: 10.0.1153 / Virus Database: 426/3287 - Release Date: 11/29/10
Bob Bownes
2010-11-30 20:40:52 UTC
Reply
Permalink
Raw Message
You can very often pick up a 5328 with the 10811 in it for < $20 plus
shipping. Last one I bought was $15 including shipping...

Bob


On Tue, Nov 30, 2010 at 3:29 PM, J. L. Trantham, M. D. <jltran-***@public.gmane.org> wrote:
> My favorite has been the 5334B with Option 010.
>
> Joe
>
> -----Original Message-----
> From: time-nuts-bounces-***@public.gmane.org [mailto:time-nuts-bounces-***@public.gmane.org]On
> Behalf Of Chris Albertson
> Sent: Tuesday, November 30, 2010 1:29 PM
> To: shalimr9-***@public.gmane.org; Discussion of precise time and frequency measurement
> Subject: Re: [time-nuts] If there a FAQ
>
> On Tue, Nov 30, 2010 at 5:33 AM,  <shalimr9-***@public.gmane.org> wrote:
>
>> Just find any HP 10811, by itself or inside an instrument (you can often
> buy a whole instrument with an internal 10811 cheaper than you can buy the
> 10811 by itself).....
>
> What HP instruments would have the HP 10811 inside?
>
> --
> =====
> Chris Albertson
> Redondo Beach, California
>
> _______________________________________________
> time-nuts mailing list -- time-nuts-***@public.gmane.org
> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
> -----
> No virus found in this message.
> Checked by AVG - www.avg.com
> Version: 10.0.1153 / Virus Database: 426/3287 - Release Date: 11/29/10
>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts-***@public.gmane.org
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>
s***@public.gmane.org
2010-11-30 20:50:49 UTC
Reply
Permalink
Raw Message
Sent from my Verizon Wireless BlackBerry

-----Original Message-----
From: shalimr9-***@public.gmane.org
Date: Tue, 30 Nov 2010 20:49:53
To: Chris Albertson<albertson.chris-***@public.gmane.org>
Reply-To: shalimr9-***@public.gmane.org
Subject: Re: [time-nuts] If there a FAQ

Many signal generators and counters, signal analyzers and the venerable HP3586 come to mind.

For sure, there are many more, but these are those I am familiar with.

Any instrument that has a "high stability time base" option is a candidate if that option was installed. But many instruments had it built-in (not as an option.)

Of the least expensive instruments I have seen with that option, the HP5370 and HP5334 can be had sometimes for less than $100 (I have 5 and the most expensive was $100)

Didier

------Original Message------
From: Chris Albertson
To: Didier Juges via Gmail
To: Time-Nuts
Subject: Re: [time-nuts] If there a FAQ
Sent: Nov 30, 2010 1:29 PM

On Tue, Nov 30, 2010 at 5:33 AM, <shalimr9-***@public.gmane.org> wrote:

> Just find any HP 10811, by itself or inside an instrument (you can often buy a whole instrument with an internal 10811 cheaper than you can buy the 10811 by itself).....

What HP instruments would have the HP 10811 inside?

--
=====
Chris Albertson
Redondo Beach, California


Sent from my Verizon Wireless BlackBerry
Loading...