[time-nuts] Re: Query about 5061B performance and tuning

[paul swed]

Jim, good morning.
On my 5061 known as Frankenstein, I used a used tube that had no cesium.
Well increasing the temperature (Home brew oven controller DC) did release
enough to operate for another 5 years of intermittent operation. But
something happened about 4 months ago and no time to troubleshoot.
That said beam has always been unreadable. Maybe a drop above zero. But it
did lock and 2nd harmonic was strong. However as it neared its end I
noticed 2nd harmonic dropping and frankly moving around amplitude wise. So
I sort of wonder if what you are seeing is noise building up. A better
comment S/N going down.
Regards
Paul
WB8TSL

On Wed, May 22, 2024 at 7:03 AM AC0XU (Jim) via time-nuts <
time-nuts at lists.febo.com> wrote:

> Time Nuts-
>
> I have attached some MADEV estimates for several cesium beam oscillators
> in my home lab (I have previously posted references to my researh papers
> about ensemble ADEV measurements).
>
> Two of these oscillators, labelled 5061B1 and 5061B6 perform worse than
> the others. 5061B6, in particular, seems to have very poor lock.
>
> 1. 5061B1 had a failed tube in which I subbed a very old but working tube.
> Prior to the failure and substitution, it performance was as shown as
> "5061B".  All standard tests from the service manual are successful. The
> Beam I is rather low (15) and cannot be increased.
>
> 2.  5061B6 is unit which, according to all the standard readings, should
> be performing well. Beam I easily set to 25. Etc. However, it isn't.
>
> Any suggestions about what I should be looking to test/tweak on these two
> units?
>
> Thanks!
>
> Jim_______________________________________________
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