A bit OT, but regarding your Rb, some units needs to be powered thru 2
pins, one is used only for the 10 MHz output buffer, if remember it
correctly. Which is your model number?
Ignacio EB4APL
El 04/11/2016 a las 16:35, Peter Reilley escribió:
I gave up on trying to use the GPS 1 PPS signal to calibrate the 10
MHz OCXO's that
I have. The reason that others have pointed out is that the
uncorrected 1 PPS
signal from the GPS is has just a little too much a jitter to use it
for calibration
with your eye using a scope. If it were sawtooth corrected then it
would be better
but you really need a GPS disciplined oscillator.
Not to be outdone, I brought out a rubidium oscillator that I had put
away because
it did not appear to work properly. It only put out a 1 PPS signal
and nothing else.
I compared that with the GPS PPS and could get a good comparison on
the scope.
The rubidium drifted about 40 nS over 12 hours. So it seemed to be
good.
With that I could adjust the OCXO's in my 5370's. The spec for the
HP 5370B with
a HP 10811 OCXO is better than 1 X 10^-10 RMS for 1 sec average. That
is, it should
take more than 1,000 seconds for one 10 MHz wave to shift by 360
degrees. That
is very hard to do using the screw adjustment in the OCXO. Even the
slightest
movement possible will cause a frequency change greater that is
spec'ed. How
do cal labs do it?
My HP 5370A has a 10544 OCXO which is spec'ed for short term stability of
better than 1 X 10^11 for 1 second. Even better than the 5370B! The
adjustment
screw is much coarser and it is not possible to get any better than a
few seconds for
one cycle phase shift of the 10 MHz OCXO against the standard. It
seems that I can't
get even close to the spec.
These have been running for a few days. It that enough?
Pete.
---
El software de antivirus Avast ha analizado este correo electrónico en busca de
virus.
https://www.avast.com/antivirus
_______________________________________________
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
