[Amps] HF amp output power dropping

[Peter Chadwick]

>The more drive I give it, the higher the filament voltage 
rises. Used to always drop under load.<
Presumably measured in the same way with the same meter - and not a DVM affected by RF?
How does the input SWR  of the amp change while this is going on?
Which bands does it happen on - all of them?
>What ALL the meters do, including grid current and exciter 
SWR, will tell you a great deal. Without knowing what the 
meters do all people can do is guess, and that isn't very 
productive.
<
Agreed
73
Peter G3RZP