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

[Magnus Danielson]

Hi,

On 07/08/2018 12:30 AM, Gregory Beat via time-nuts wrote:
> In 2008, G Molenkamp, VK3UM noted that of the 20 Efratom model FRS-C units he restored, component failure due to long heat exposure caused most of the failures. 
> http://www.vk3um.com/Rubidium%20rejuvination.pdf
> He notes that some lamps had Rb splattered over the inside wall of the glass.  
> In these cases, the Rb material was not consolidated in the “pinch of the glass lamp”.
> Using the “heat gun process” he was able to rejuvenate those Rb lamps.

I later tried that method on my R&S XSRM rubidium, with good progress. I
have reported on that on the list way back. It took two attempts, one
just to realize that I needed to keep the pinch at the top, because that
is where the hot atoms go.

Essentially, the thin film of rubidium will consume too much of the
radiation to emit any useful amount of pumping light. Heating it has the
rubidium go into gas and then collect somewhere cold, so it's just about
making sure that somewhere cold isn't the glass where it is to emit light.

My XSRM have however other issues that I need to attend to.

Cheers,
Magnus

> w9gb
> ==
>> Time-Nuts Group,
>> 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.
>> Contact me if interested.
>> Don
> 
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