> Rich,
>
> My data sheet shows 25 watts which works out to be a grid current of
> around 380mA. This seems too high. I fear that it may not be that
> simple (mixing AC and DC characteristics) although my tube theory is
> fluffy at the best of times.
David,
I do have two programs that use constant current characteristics to
calculate dissipation.
They essentially agree with that, but of course HV, minimum anode
voltage, and other parameters move the dissipation around a bit.
250mA, under most operating conditions in AB2, results in
approximately 20 watts grid dissipation, and 350mA is about the
lowest grid current I could obtain that exceeded grid dissipation
ratings.
Of course it is best to use as little current as possible without
hurting efficiency.
73, Tom W8JI
W8JI@contesting.com
|