[time-nuts] WTS: Efratom PTB-100 Precision Timebase

Don@True-Cal truecalservices at gmail.com
Sun Jul 8 17:57:25 EDT 2018

Thanks Attila,

Yes, that is a procedure I know about. The lamp glow is purple and my lamp
monitor voltage is 6.36, not great but should be in the working range. The
issue I'm trouble shooting right now is the PS transition from supply
voltage, 28V in my case, to 17V after lamp ignition is not stateful. It
starts pulsing to 17V after ignition and the duty cycle slowly transitions
from mostly at 28V to mostly at 17V over time - never stays at 17V. The PS
is working correctly though because the photocell preamplifier output is
causing the pulsing. I have the oscillator trimmer cap set for symmetrical
frequency change 4Hz above and below 10MHz following the integrator EFC but
the EFC sweep is 6.5V to 13.5V and I would expect the low end should start
closer to <1V. Still reading the manual and studying the circuits.


-----Original Message-----
From: time-nuts <time-nuts-bounces at lists.febo.com> On Behalf Of Attila
Sent: Saturday, July 07, 2018 2:32 PM
To: Discussion of precise time and frequency measurement
<time-nuts at lists.febo.com>
Subject: Re: [time-nuts] WTS: Efratom PTB-100 Precision Timebase

On Fri, 6 Jul 2018 20:56:56 -0500
"Don at True-Cal" <truecalservices at gmail.com> wrote:

> For someone interested in working on the Rb package which I believe is 
> the FRK series. Worked great in my lab for years and recently started 
> being real slow to lock during power cycles and now won't lock at all. 
> Not sure what the fair asking price would be in this condition. Maybe 
> someone has repair/refurb experience with the Efratom FRK.

It is likely that the lamp degraded to the point it doesnt produce enough
light anymore. People have reported that they could revive old lamps by
heating it up with a heat gun and let the rubidium condense again at the
nook where it is supposed to be.

			Attila Kinali

<JaberWorky>	The bad part of Zurich is where the degenerates
                throw DARK chocolate at you.

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