From what's been reported here, the mechanism isn't consumption of the
Rb, but rather deposition of material on inside of the bulb, reducing
its intensity, and that can sometimes be reversed by tricks that some
time-nuts have reported -- it's more of a maintenance rather than a
wear-out issue.
I think that's quite different from a Cesium tube, where the cesium is
actually depleted as it is ionized and sent down the beam.
Otherwise, there are failure modes that result from components running
at elevated temperatures for many years. I'd also consider those
maintenance.
John
----
On 11/14/2012 11:56 AM, Bob Smither wrote:
Do Rb oscillators wear out? I have found:
"There are no “wear-out” or “use-up” mechanisms in a Datum
Efratom Rubidium oscillator."
-- Datum - Note About Rubidium Oscillators
and
"Atomic Vapor Oscillators have no wear out mechanism."
-- FEI - Precison Oscillator Overview, 2007, p19.
But also:
"Unlike a quartz crystal oscillator which has no clearly-defined "wear out"
period and, if well-designed, can actually improve as time goes on, a Rubidium
reference has a definite lifetime associated with its lamp: As the unit
operates, the Rubidium within the lamp is gradually consumed and eventually, too
little vapor is available for the atomic resonance to be detected and the unit
fails."
-- http://www.ka7oei.com/10meg_rubidium1.html
and
The page at:
http://www.oscilent.com/esupport/TechSupport/ReviewPapers/IntroQuartz/vigcomp.htm
also mentions a wear out mechanism.
and
"These OCXOs maintain performance characteristics comparable to Rubidium
oscillators without their high cost and inherent wear out,"
--
http://www.microwavejournal.com/articles/2301-an-ocxo-with-rubidium-oscillator-performance
Finally I found:
"Problems with rubidium cell wear-out have been solved and manufacturers now
offer essentially unlimited warranties against cell failure."
--http://www.endruntechnologies.com/frequency-standard-oscillators.htm
so maybe both points of view are correct?
I recall seeing something about rejuvenating Rb oscillators on this list, so I
suspect Clint is correct.
Whose right? As a time-nut, do you leave your Rb oscillators on 24/7?
Thanks,
_______________________________________________
time-nuts mailing list -- [email protected]
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
_______________________________________________
time-nuts mailing list -- [email protected]
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
