I have tweaked mine to my satisfaction now. An offset of -768 gets it
as close as I can measure under sub-optimal conditions. See results at
bottom.
I am still curious as to whether Rubidium exhibits the same resonance
peaks that Cesium does, per Tom Van Baak's graph at
Hi
A few generic Rb information points:
1) All the telecom Rb’s need an external heatsink. To just mount them on
a PC board, you need a lot of airflow (like fans …).
2) Heat sinking improves the lifespan of these devices. Without a heatsink,
a year or two is doing pretty well. With a heatsink
There is a lot of information in the Time-nuts archives relating to the FE5680,
and all the commands you need
for reading and programming the unit are in the manual, as best I remember I
just used Hyperterminal.
Just in case you're not aware of it, the Google site specific search string
> Hmmm...
> You mention varying suply voltage by 1.5V, but from where as a starting point?
Sorry, that is a red herring. The regulator on the support board needs
enough headroom to regulate to 15V for the FE5680A. Thus anything less
than about 17V input will drag down the voltage into the unit,
Hmmm...
You mention varying suply voltage by 1.5V, but from where as a starting point?
It's been a while since I calibrated an FE5680A but looking back through my
notes, doing it "properly" is, or was for me anyway, a non trivial exercise.I'm
not familiar with the Windows software mentioned but
I wonder if my FE-5680A is locking to the wrong resonance, or that I've
tweaked it too far off the main one.
Setup:
FE-5680A Rubidium oscillator with passive support/breakout board,
ostensibly regulated with an LM1084-ADJ. Trimble Thunderbolt GPSDO,
feeding an HP-53131A universal counter as
