[Amps] re: baking out tubes

[Bill Fuqua]

     If the tube has no getter baking out requires a high vacuum system. 
The gas has to go somewhere after being driven off the internal surfaces of 
the tube.
    There is another process called conditioning where the tube operated at 
normal filament voltage and the plate current is kept low. The plate 
voltage is raised ( current limiting requried) to the point  where a spark 
is produced. This spark evaporates the sharp the small sharp irregularity 
that that was the cause for the low break down voltage. The process is 
repeated until the desired plate voltage is reached. This is how they make 
some not pulse rated tubes into pulse rated tubes.

73
Bill wa4lav


At 01:39 PM 10/24/2004 -0400, carl seyersdahl wrote:
>   After reading about this subject I"m wondering about the requirements to
>"bake out" a tube. !! do you run it with full filament voltage or percentage
>lower? how about plate voltage?? screen? do you let it run any plate
>(anode)current ??  How do you know when it's safe to use at normal voltages
>?  Another inquiring mind.!!!
>    carl / kz5ca
>
>
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