[AMRadio] Class C modulation

[wwd at netheaven.com]

>I have verified that with my HF-300 rig. It uses a pair of them in 
>pushpull in the final. Once,  I wanted to check out a single tube for 
>performance, so I took one of my many HF-300 duds and cut off one of the 
>filament pins and used the crapped out tube as a neutralising dummy. The
>first time I fired up the rig with only one tube in the final, the
>meters  read almost exactly the same as when I had two tubes.  It
>immediately became obvious what was happening, so I quickly decreased
>the loading until the one operative tube drew normal plate current (1/2 
>the normal total plate current to the final).

>Don K4KYV

What, if anything, would argue against continued operation with just the
single tube, as well as the dummy? The dummy would maintain correct
neutralisation, you've already reduced loading on the working tube, and
now your existing audio power will be that much more effective. Sounds
like a happy equation. Perhaps the Q of the final is now different due to
1/2 plate current. Big deal? What happens to Class C efficiency?

Bill    N2KQA
-- 
-------------------------------------------------------------------------------
wwd at netheaven.com  To the warriors go the spoils of war; to the hindmost .  .  the surplus.
-------------------------------------------------------------------------------