[time-nuts] HP5061B Beam Tubes

[EWKehren at aol.com]

Twelve years ago I did disassemble a regular and a high  performance tube, 
the only negative effect was I joined time nuts. The guts  still decorate my 
window sill. The only parts inside that may be temperature  sensitive are 
some copper wires with a clear coating. Every thing else is metal  or ceramic.
Bert Kehren
 
 
In a message dated 9/23/2013 5:44:22 P.M. Eastern Daylight Time,  
john at miles.io writes:

I've  always wanted to try baking the entire tube to vaporize any
accumulations  of Cs metal outside the internal oven.  Is that what you  
did,
Paul?  If some of the free cesium metal near the detector can be  
recondensed
at the oven end, or just redistributed uniformly throughout the  tube, it
might render a noisy tube usable again.

The point at which  cesium vaporizes is 250C / 482F, and that seems like it
could be survivable  unless there are thermoplastic structures or insulation
sleeves inside the  tube for some reason.  The operation might be tricky,
because while  you wouldn't want to heat the tube sufficiently to vaporize
all of the  remaining cesium in the internal oven, you would also need to
bake the tube  for quite some time to heat its internal structures 
uniformly,
since it's  basically a vacuum bottle.  Outgassing from various internal
materials  and structures would also be a concern.  Something to try with a
tube  that is otherwise ready for the scrap heap...

-- john, KE5FX
Miles  Design LLC

> -----Original Message-----
> From:  time-nuts-bounces at febo.com [mailto:time-nuts-
> bounces at febo.com] On  Behalf Of paul swed
> Sent: Monday, September 23, 2013 12:52 PM
>  To: Discussion of precise time and frequency measurement
> Subject: Re:  [time-nuts] HP5061B Beam Tubes
> 
> Tom
> I added 10 degrees  and used the built in temp sensor in the tube as a
> gauge. So its sort  of accurate to say 10 degrees. I remember evaluating
the
> temp  several ways.
> I did not return it to original temp as I believed at  the time I was
baking
> out the last few Cs.
> What your saying  in the threads very interesting. But don't have time to
go
> back and  adjust or reconnect the old oven controller. I would have to 
look
> at  all of that again to see whats needed. I did this about 2 years ago  
its
> in the time nuts archive I suspect.
> Regards
>  Paul.

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