At 15:35 09/12/98 -0000, you wrote:
>
>
>
> Dan says:
>
> > normally load "heavy" to reduce grid current after full output
>tune. Power
> >out suffers only 25-50 watts.
> >This must be where the improved IMD comes from.
>
>If you are winding down the drive to get down to the legal limit, the
>improvement in IMD because of less swing dominates. Underrunning a big amp
>in this way should help reliability, life (tube and other parts) and IMD.
>What the marketeers call 'a win-win situation'.
>
As long as the amplifier is correctly biased and not nearly in class C !
I found this out when a transistor amplifier bias failed because of a dry
joint. Seemed linear from 10W-100W. Didn't check that there was no output
at low drive, who does when you can't reduce the drive to zero? Most HF
rigs seem to only be variable from 10W to 100W.
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