>
>I have a pair of 4CX800A tubes that have been on
>the shelf here for a few years (and for an unknown
>period before I got them). I'm about to swap them
>into one of my Alpha 91b amps.
>
>Is there a recommendation to let these tubes run
>without HV for a period before pressing them into
>full service?
>
>I did a search of the archives, and it seems that
>there is no consensus on the need for this procedure
>for any but the largest "tubes with handles".
>
? Even for a gassy tetrode with handles, I have never found one that
would magikly get mo' betta by operating the filament. The bottom-line
seems to be: if there's gas, you'd better pass. However, if there's a
leaky ceramic-metal seal, Econco can resolder it during the rebuilding
process. It is my opinion that Ham radio is not free from old wives'
tales.
cheers,
> Jeff Maass K8ND
Jeff, Rich, et. al
If I recall we discussed this on the list back in September 2001 and
the conclusion was that that for small tubes there is no requirement to
"condition" them.
We talked about getters and ion pumps in some of the larger tubes
and the conditioning process(es) that might apply to them.
I recall reading somewhere recommendations for 8877's to be run
on fils and blower only for 24 hours before use of a new ("green")
tube and did with mine before taking it in to service, but suspect it
was totally un-necessary.
So, in short there are no Eimac recommendations for smaller tubes
but you can if you want and think it might make a difference - it doesn't
appear to do any harm.
Mike G8TIC/M0VHF/M0BAA
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