[time-nuts] Re: HP 5065A, no 2nd harmonic.

[paul swed]

Jared
OK lets start.
Can you share a bit with us please.
Whats types of test equipment do you have.
Believe we will need a scope, DVM (Reasonable grade), audio sig gen,
perhaps a fairly good reference GPSDO. I am coming at this with the
possibility the issue could be anyplace.
The suggestion that the oven temps could be off is a good one. Though I
have not so far run into that on CS or Rb references. I need to pull the
5065 manual and take a look but injecting small amounts of first and second
signals should make the meter tick upscale. I believe that is 137 and 274
hz. Its possible and I have seen this issues simply on the metering board.
But want to approach it logically by eliminating the detector chain.
Regards
Paul

On Thu, Nov 18, 2021 at 12:56 PM Jared Cabot via time-nuts <
time-nuts at lists.febo.com> wrote:

> Hi all,
>
> I have a 5065A Rubidium Standard that was working ok, but has lost the 2nd
> harmonic.
> My voltages are all ok, the physics package hasn't overheated and I have
> replaced the usual resistors on the lamp assembly (and it was running fine
> afterward for a while), the lamp illuminates, and I've done the procedure
> to remove cell flooding.
> All readings on the 'circuit check' switch are nominal, apart from the 2nd
> harmonic position. No matter what I do, I can no longer get it to raise
> above 0.
> However, when I first turn the unit on, the needle drops to 0 and flicks a
> little before settling on 0 and staying there.
>
> Can someone help me get this unit up and running again?
>
> Thanks!
> Jared_______________________________________________
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