Re: 4-1000A Screen Biasing...

["Ed Phillips" <evp-at-pacbell-dot-net> (by way of Terry Fritz <twftesla-at-uswest-dot-net>)]

> This one comes up a lot in high power audio amps. There is
> really no substitute for a well regulated standalone screen
> supply which is usually derived from a separate transformer
> winding where screen current is high, or in cases where it is
> required to be half the anode supply, the half point of a full
> wave voltage doubler.
>      The screen current should be self-limiting if the correct
> anode supply and operating point is used.
> 
> Regards,
> Malcolm

	True, BUT.......  If the separate supply is left on after the plate
voltage is removed or turned on before it is applied, all of the cathode
emission will be intercepted by the grid and the tube may be wrecked.

Ed