>Even assuming they were
>equals in this respect;
>2b. 3-500 = 500W plate dissipation. 4-400a = 400W.
>2c. 3-500 = 20W grid dissipation, 4-400 = 10W
Why should these parameters affect the gain, and the maximum output power
(as opposed to the maximum before the glow of the plate is judged to be too
bright?)
> > 1. where is the extra drive power going?
>
>>1. The extra power is going to turn on (drive) the tubes and being
fed >>through
>>to the output.
But the gain of the 4-400 is less than the 3-500 when running grounded grid,
(from Lane's figures, 1.87 dB less) so although the drive power is fed
through, there's less 'added power'.
I get about 9dB gain from a single 4-400 with 3600 on the plate on a single
band 10m amp. It flattens (i.e. the input/output power transfer
characteristic) at about 550 watts output on single tone, and the PSU is
pretty well regulated.
73
Peter G3RZP
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