Re: 4-1000A Screen Biasing...

[paul-at-abelian.demon.co.uk (by way of Terry Fritz <twftesla-at-uswest-dot-net>)]

Tesla list wrote:

> I have two 4-1000A tetrodes which I am using for a
> VTC....2000 ARRL handbook lists
> typical screen current to be 146 mA ...
> ...Does this imply that that the screen bias
> resistor will have to drop 2.5KV WRT GND and limit the
> current to 145mA? 

You must use a stabilised supply for the screen, and it
is vital to arrange interlocks to ensure that screen voltage
is not applied unless  anode (plate) voltage is present,
otherwise the screen grid will be seen by the electrons
as the anode and the valve will destroy itself very quickly.

--
Paul Nicholson,
Manchester, UK.
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