Bob,
Which category do the FE-5680A's fall into?
Dale
NV8U
-----Original Message-----
From: Bob Camp
Sent: Wednesday, November 14, 2012 6:28 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Confused about Rubidium oscillators
Hi
There are several different basic Rb cell designs. The old "large cell"
designs had relatively little trouble with glass / metal interaction. The
early small cell designs tended to turn the bulbs black over time. Newer
small cell designs seem to have gotten past that problem.
Bob
On Nov 14, 2012, at 5:46 PM, Brian Kirby <[email protected]> wrote:
I believe Corby came up with the bulb "rejuvenation".
If you tried to get a new bulb for a FRK, they wanted $400 in the late
1990s for them.
Several rubidium's are plentiful and cheap, it may be easier to buy one
from the auction site.
I have a HP5065A, I run it when I need it, and when not in use, I power it
up about every 3 months for a couple of days. On the HP unit, there is a
flooding/pooling problem if the unit is not used.
On 11/14/2012 10:56 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,
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