>Rich,
>
>One other point on drive level:
>
>If the point were true that input impedance varies with drive, then in
>order to have an amplifier system that is operating properly, one must
>always operate it at maximum drive.
>If not operated then at maximum
>drive, the matching network is not properly attenuating harmonics, not
>providing the proper "flywheel" affect, etc.
- The flywheel makes things mo betta, and it's always there.
.
>It is not always beneficial to run an amplifier at maximum drive.
During ssb modulation, the drive varies widely during each spoken word.
However, max. peak drive and max. anode-I is essential to correct tank
adjustment.
>You might just want to run with 500 watts out instead of 1500. Or you might
>be running RTTY. In both cases, you would need to back off on the drive.
>
>I know there is a difference between small signal and large signal
>S-parameters in an active device. The question is is 5 watts considered
>a small or large signal condition? Perhaps you are right in that the RX
>noise bridge is too low a level if 5 watts in is considered large signal.
> We shall see. I don't really think there is that much difference
>between small and large signal impedance variations, however.
When you hook a large signal Z-analyzer direct to cathode, you will know.
Please consider that: Below a certain drive level, zero grid current
flows. At max. drive, grid current flows.
>
- later, Jon
cheers
Rich...
R. L. Measures, 805-386-3734, AG6K
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