[Amps] 8877 Max Grid Current

[Tom Rauch]

> 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