[time-nuts] Man with too many clocks.
EB4APL
eb4apl at gmail.com
Fri Nov 4 17:07:03 UTC 2016
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.
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