On 1/26/19 10:43 AM, Bob Albert via time-nuts wrote:

If your email name is your zipcode in North Hills, then you're a bit far
away from JPL to pick up the omnipresent 10MHz (and harmonics) that's
leaked/radiated everywhere on lab. For most of the leakage, it's
probably based on either local Rb or GPSDO in the specific lab, or
locked to the lab's maser distribution.  Generally fairly close to "dead
on" ( a very narrow spectrum analysis from a whip antenna is fascinating..)

It's an idea..

If you have microwave receive capability, several of the amateur beacons
in the Los Angeles area are now locked to a GPSDO - I don't know which
ones off hand, but an email to someone in the SBMS (San Bernardino
Microwave Society) would probably be useful.  For that matter, their
monthly meetings often have someone there with a Rb source that you
could use to calibrate, or arrange to meet up with.

There's also some microwave shootouts in the area where everyone goes to
measure their noise figure and antenna gains, and I guarantee that at
one of those, someone will have a high quality frequency standard.

Well you are right that I am bit far from JPL.  I used to work there.  But I am impressed with the number of replies and the number of suggestions.  I am still mulling over what will work for me.  Apparently this group is made up of helpful and knowledgable guys who aren't afraid to share their expertise.
I don't have a microwave receiver.  I don't even know what frequency range I might want to hear.  Yes there are amateur beacons but the only one that stands out in my mind is the one in Long Beach on 10 meters.  Given its target frequency, I am a bit at a loss as to how to make use of its accuracy.  I could use a local signal generator as a transfer oscillator and measure it while trying to hold it on zero beat with the beacon.
Great stuff but I do have gaps in my knowledge that I'd love to close.
Bob
On Saturday, January 26, 2019, 1:00:23 PM PST, jimlux jimlux@earthlink.net wrote:

On 1/26/19 10:43 AM, Bob Albert via time-nuts wrote:

If your email name is your zipcode in North Hills, then you're a bit far
away from JPL to pick up the omnipresent 10MHz (and harmonics) that's
leaked/radiated everywhere on lab. For most of the leakage, it's
probably based on either local Rb or GPSDO in the specific lab, or
locked to the lab's maser distribution.  Generally fairly close to "dead
on" ( a very narrow spectrum analysis from a whip antenna is fascinating..)

It's an idea..

If you have microwave receive capability, several of the amateur beacons
in the Los Angeles area are now locked to a GPSDO - I don't know which
ones off hand, but an email to someone in the SBMS (San Bernardino
Microwave Society) would probably be useful.  For that matter, their
monthly meetings often have someone there with a Rb source that you
could use to calibrate, or arrange to meet up with.

There's also some microwave shootouts in the area where everyone goes to
measure their noise figure and antenna gains, and I guarantee that at
one of those, someone will have a high quality frequency standard.

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On 1/26/2019 1:31 PM, Bob Albert via time-nuts wrote:

Bob, If you are willing to spend $70 you can get a fairly decent GPSDO
receiver from eBay. For that money I recently bought a Samsung UCCM
gpsdo.  Add to that the price of an antenna, cable(s), case and power
supply and you'll be good to go with a 10 MHz signal that will be
perfect for your needs.  I recommend the UCCM boxes for you because they
are pretty well automated; when first connected they do a self survey,
store the position they find and then start to output very accurate 10
MHz and 1 pps signals, all with no outside intervention.  Not so popular
perhaps with time nuts who would like to be able to tune their devices
for ultimate performance but the simplicity of these can't be beat. Now
you can calibrate your OCXO in place, or better still just feed the
counter from your GPSDO.

If you can't get an antenna up with a good view of the sky to the south
then Rubidium units are available which once set will do you for
years.   I'm guessing, maybe double the figure I quoted above, then add
power supply and case.

Calibrating your OCXO won't be easy if you do it elsewhere. First most
OCXOs will take about two days to settle, then the frequency will depend
to some extent on the unit's orientation. Finally if you turn it off and
then on again, it may well come back to a slightly different frequency,
that's called retrace. And all OCXOs will drift over time, some worse
than others.

Dan

ac6ao

On 1/26/19 1:31 PM, Bob Albert via time-nuts wrote:

I'd shoot an email to someone in SBMS - they're all over southern
california - there's probably someone out in the valley close to you and
you can just schlep your counter over there.  Or go to their meeting..
they're always interesting (and for all you know someone will be selling
a GPSDO or Rb cheap or a recently adjusted OCXO cheap)

On 1/26/2019 10:43 AM, Bob Albert via time-nuts wrote:

There is no standard oven oscillator.  There is a high priced
optional oven oscillator (10544).  There is a standard non
oven oscillator which is very basic and is not good for much
accuracy.  So what oscillator do you actually have?

What frequency do you want to measure with your 5328 anyway?
Not much call for counters these days.

Rick N6RK

On 1/26/19 4:31 PM, Bob Albert via time-nuts wrote:

Bob,

Frequency counters are practically redundant these days. Ovens and GPS make transmitting accurate.
I don't go to the bands' edges, and the timing in the radios is fine, even back to my IC-735 and
Eddystone EA12, from G3YTO, sadly dead long ago.

Ten or twelve digit frequency measuring is just a game mostly for a lot of us here.

Ian, G4ICV, AB2GR

Well Ian there are lots of guys on nets using archaic equipment.  I go to some of their swap meets.  I have repaired, built, and salvaged many of those old items.  Of course back then the 1 kHz resolution of Collins gear was amazing.  I built a frequency meter a while back.  An interesting design inspired by GE Ham News.  It utilized a VFO that would tune from 100 kHz to 110 kHz I think.  The harmonics would, after a while, overlap so the entire tuning range was covered by about 25 turns of a vernier dial.  I could resolve much less than 1 kHz and it was very accurate.
I still have a BC-221T that is almost pristine and works great.  Back in the day I also had an HP 524 counter but not until I got some use out of a Beckman unit for which I built a 10 MHz counting module.
I have always enjoyed measurments, and I feel fortunate that I can do the things I do.  I just repaired the test leads on my GR 1658 bridge, and am in the process of learning to use a couple of VNAs I recently acquired.
Unfortunately I am an old man and don't know how much time I have left.  But I do plan to make the most of it.
BobK6DDX
On Saturday, January 26, 2019, 6:00:44 PM PST, Ian Stirling is@opus131.com wrote:

On 1/26/19 4:31 PM, Bob Albert via time-nuts wrote:

  Bob,

  Frequency counters are practically redundant these days. Ovens and GPS make transmitting accurate.
I don't go to the bands' edges, and the timing in the radios is fine, even back to my IC-735 and
  Eddystone EA12, from G3YTO, sadly dead long ago.

    Ten or twelve digit frequency measuring is just a game mostly for a lot of us here.

Ian, G4ICV, AB2GR

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Hi

So what’s the downside to all this:

Keeping an OCXO (and counter) turned on 24 hours a day, 365 days a year burns power. If you
also live in air conditioning land, you pay even more to get rid of the heat from the power.
Sit down and do the math. You likely will find this is not as cheap as it first seems.

A GPSDO running over the same time period also chews up energy. It might use less, it might
use more. A lot depends on exactly which model of each. Same thing on an Rb while it is running.
(note that sneaky qualifier).

The neat thing about the Rb is that you can turn it on today and it will be doing pretty darn well tomorrow.
Do your measurements and shut it down again. Since cost isn’t very different between a GPSDO and
an Rb, the comparison is not too far fetched.

If you happen to play with radios, having a 10 MHz reference will get into things. Same may be true of
harmonics of 10 MHz. How much and how often it is an issue depends on a lot of things. Turning
the whole thing off eliminates the problem.

Regardless of what you are running, keeping it on 24/ 365 will cause some wear on some parts of it.
That’s just the way MTBF’s work out. Turning on and off also creates issues so there is no magic way
to eliminate failures. It is a pretty good bet that a device that is off 99.99% of the time will live longer than
one that is on power all the time.

So no, it’s not a one size fits all sort of thing. The solution that makes sense in one case will be
needlessly expensive in another case. If it’s a focus of a hobby, that is different. If it is just another
tool in the tool chest, no need to overspend. Save the hard earned cash for something else.

Bob

Frequency counting is far from dead yet,  When instruments especially those interesting to time nuts are calibrated a counter is usually an essential instrument.  Also for analog design/repair work.

But for a lab reference frequency its hard to beat a thunderbolt / jackson labs board + Lady Heather for 10 Mhz + 1pps  for both initial cost and long term operating cost (power and cooling)

As to calibrating oscillators for service grade equipment my favorite is still the old HP Lissajous method as that gives both an accurate calibration plus it gives you the short term drift of the oscillator.

Here is a short description of the process from the NIST Time and Frequency users manual on google books

https://books.google.com/books?id=lRmeSxMi2VYC&pg=PA54&lpg=PA54&dq=lissajous+oscillator+calibration&source=bl&ots=AL57BSuSoL&sig=ACfU3U1XGKOIoDZ9fJhfr9jqzzIYHV8mtw&hl=en&sa=X&ved=2ahUKEwj7rY6YlY7gAhWIneAKHVicBhQQ6AEwD3oECAkQAQ#v=onepage&q=lissajous%20oscillator%20calibration&f=false

There is also a really good discussion about this in the HP 5345A operating and service manual in the oven adjustment section.

Yes there are better methods but they need more hardware than a known reference and an oscilloscope

Content by Scott
Typos by Siri

On Jan 26, 2019, at 9:58 PM, Bob kb8tq kb8tq@n1k.org wrote:

Hi

So what’s the downside to all this:

Keeping an OCXO (and counter) turned on 24 hours a day, 365 days a year burns power. If you
also live in air conditioning land, you pay even more to get rid of the heat from the power.
Sit down and do the math. You likely will find this is not as cheap as it first seems.

A GPSDO running over the same time period also chews up energy. It might use less, it might
use more. A lot depends on exactly which model of each. Same thing on an Rb while it is running.
(note that sneaky qualifier).

The neat thing about the Rb is that you can turn it on today and it will be doing pretty darn well tomorrow.
Do your measurements and shut it down again. Since cost isn’t very different between a GPSDO and
an Rb, the comparison is not too far fetched.

If you happen to play with radios, having a 10 MHz reference will get into things. Same may be true of
harmonics of 10 MHz. How much and how often it is an issue depends on a lot of things. Turning
the whole thing off eliminates the problem.

Regardless of what you are running, keeping it on 24/ 365 will cause some wear on some parts of it.
That’s just the way MTBF’s work out. Turning on and off also creates issues so there is no magic way
to eliminate failures. It is a pretty good bet that a device that is off 99.99% of the time will live longer than
one that is on power all the time.

So no, it’s not a one size fits all sort of thing. The solution that makes sense in one case will be
needlessly expensive in another case. If it’s a focus of a hobby, that is different. If it is just another
tool in the tool chest, no need to overspend. Save the hard earned cash for something else.

Bob

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