[time-nuts] How Rubidiums make their frequency (was RE: time-nuts Digest, Vol 21, Issue 22)
rexa at sonic.net
Thu Apr 20 05:55:37 EDT 2006
On Thu, 20 Apr 2006 02:31:08 -0700, "Christopher Hoover"
<ch at murgatroid.com> wrote:
>That's a good explanation, thank you. I got that much already. (While it
>took some time for my phyiscs, chemistry and semiconductor physics studies
>to kick back in, it all clicked last week.) The Tracor, indeed, seems
>fairly ordinary compared to the other Rb's I have, going by the test points
>and the various labels inside. There is the typical synthesizer section,
>audio demodulation section for the photocell, etc.
>So what I'm really wondering is this: is there a wear mechanism or failure
>mode in the physics package that might explain why I have to crank the mag
>field almost to its high limit to get 5 MHz? (This question presumes the
>mag field control is working properly, and I cannot say for sure that it
I could be way off, but are you sure the xtal osc is centered on the
Having the adjustment procedure for your unit would be a good advantage.
I got an Efretom rubidium a few years back that would not lock. I went
through all the proceedures and found that the crystal had drifted out
of the lock range. I was able to get it working but at the limit of the
xtal trimmer. Had to change a fixed capacitor to get it back near the
mid of the xtal trimmer.
So, I'm thinking I might have got it locked by messing with C field if I
had a problem like this. Would have locked but off correct freq.
Not sure if this is a reasonable discussion, you may have this stuff all
understood. Do you have the full service documentation?
More information about the time-nuts