Re: GL-434A tube (specs wanted!)

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "by way of Terry Fritz <twftesla-at-uswest-dot-net>" <cwillis-at-guilford.edu>


 

Hi Ed,

All very good points.  I have sockets for them, which should facilitate
connections somewhat.  I think they will be prone to VHF oscillations,
which may be prevented with the resistor / coil impedance that is
frequently stuck in line with the plate leads in broadcast amps.  Not quite
sure what to do with grid no. 2 yet...for plasma tweeters, modulation can
be introduced here, and perhaps it's a way to throttle the coil's power.
Some people have just wired both grids together, with the disadvantage that
the tube curves and normal operating parameters are not available.  Plate
voltage is listed at 2 kV in my handbook...and to me this means they will
probably manage 3 kV with care.  I am going to try them in a push-pull
circuit, which I hope to use to drive a "half wave" type of coil.  I'll let
y'all know what happens...

CW

> Don't have anything on the 434A, but some experience with the 4X150
>series of tubes.  First of all, not particularly convenient
>connections.  Rather fragile when it comes to overheating, and I'd be
>careful about the maximum plate voltage.  Probably prone to VHF
>parasitic oscillations, particularly if you parallel several tubes to
>get more power.  Also, I would prefer triodes over tetrodes.  In spite
>of all those words of caution they can probably be made to work OK, but
>not as easily as a good power triode(s).