[Amps] Re: Amps Digest, Vol 12, Issue 33

[R.Measures]

...
> >I am also told that many high power RF
>> solid state devices have a definite life cycle.
>
>They do. As I mentioned above, a solid state device has about two orders of
>magnitude greater MTBF than a tube
>
**  A 4cx1500A and larger, similar tetrodes can be rebuilt >20-times by 
recarburizing the thoriated-tungsten filament/cathode.  Each rebuild is 
good for c. 20k hours of useful emission.