Joe Subich, W4TV wrote:
> If you don't retune the output network when operating in a
> continuous power mode (CW or RTTY) at a lower power level,
> the loading will be incorrect. Linearity may or may not
> suffer, efficiency will certainly suffer, and since the
> loading is incorrect it will be difficult without doing
> the math or taking measurements in an intentionally miss-
> tuned amplifier what the voltages/currents in the tank
> are.
>
> One thing is certain, improper loading has caused more
> damage to amplifiers than any other cause. Intentionally
> mistuning an amplifier is, to quote the President, "stupid."
>
If that line of reasoning were true, then we would be required to never
talk softly when transmitting. It seems obvious that once tuned for 1500
watts, any output less than that will result in lower currents and
voltage swings. Yes the plate voltage soars a bit, but it does than when
talking softly as well.
If you really want to chew on something, think about tuning to 1500 CW
with sagged plate voltage and hit the amplifier with the first voice
peak when the plate supply is still fully charged...probably goes to
more than 1500W...and it's not properly tuned for that condition.
It amazing that anything works at all.
jeff, wa1hco
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