833A's were widely used in AM broadcast transmitters both as finals and
modulators of about 500W to 1KW rigs (RCA BT-1 etc.) and as drivers in higher
power transmitters. I've seen designs for ham transmitters using them but I
don't know if any commercially made _ham_ transmitters did.


--
Richard Knoppow
Los Angeles
WB6KBL


On page:

http://www.criticalradio.com/833%20R...%20Article.htm

you find the diagrams of an AM transmitter using two 833s in parallel (class C),
modulated by a push-pull pair of 833s.

Reducing the grid bias down to about -70V, you may operate the 833s in class B
for linear operation, still grid-driven.

It may however not be easy to maintain the neutralization bridge nulled on the
whole 3 - 30 MHz frequency range, and you may have to switch different
capacitors in the bridge on the various bands.

Alternately, you may try a grounded-grid filament-driven configuration. You
should then keep the filament at about +70V with respect to ground (using a 100W
NPN power transistor with a 70V zener between collector and base). I however
fear it may be hard to drive.

73

Tony I0JX