Hi Robert,
If your 10811 10 MHz oscillator is off by 0.08 Hz after 20 years it's
equivalent to an average frequency drift rate of only 0.08/1e7/20/365,
or 1e-12/day. If so, you have an absolutely superb 10811; one that's
500x better than spec. Congrats! Don't power it off, don't touch it,
don't move it, don't tilt it, don't sell it.
Still, there are a lot of assumptions here:
- Do you know how closely was it calibrated 20 years ago?
- Did anyone measure it once a month or even once a year since then?
- Do you have reason to believe the frequency drift rate is constant or
predictable?
- What's the environment been like (temperature, humidity, pressure)?
- How much do you trust your cheap China GPSDO?
- What does your 53131A counter say over gate times of 10 s or 100 s,
and over an entire day or week?
- Was this a one-time lucky measurement or is your 10811 really this
good day after day after day.
Lots of questions. What I mean is that you may have one of the best
10811 ever seen, or something's funny with the above assumptions. The
nice thing about a precise time & frequency hobby is that, without too
much effort, you can figure this out.
Still, 0.08 Hz out of 10 MHz is 1e-8, or 0.01 ppm, or 10 ppb, so
depending on the accuracy that you need for the amateur radio club, it
may be plenty good enough as-is.
/tvb
On 12/26/2019 8:51 PM, Robert DiRosario wrote:
I am trying to calibrate some equipment at the amateur radio club at
work, and my stuff. We have an HP 5340A with a 10811 inside. It must
have been upgraded at some point in the past, the display uses Nixie
tubes. I calibrated it c2000 using a HP Cs standard. That lab and
it's equipment are gone. :-(
From ebay / China I got a simple GPSDO that uses a Trimble 57963
inside. I use the output of the 10811 in the 5340A to drive an HP
53131A. I then measured the 10 MHz output of the GPSDO using the HP
53131A and got 10,000,000.08 Hz.
Assuming the GPSDO is correct, is 0.08 Hz drift over 20 years a
reasonable amount of drift for an 10811?
I have an HP Z3801A, once I get a power supply for it I can check the
other GPSDO.
Thanks
Robert
KA3ZYX
_______________________________________________
time-nuts mailing list -- [email protected]
To unsubscribe, go to
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
_______________________________________________
time-nuts mailing list -- [email protected]
To unsubscribe, go to
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
