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This brings a question to mind. Most solid state RF amps I've seen (both for ham radio use and for CB) typically use transistor pairs, which I'm assuming are operating in a push-pull configuration, as described in the article. That is, for a given sine wave cycle, one transistor amplifies one half of the sine wave (when the voltage goes positive) and the other transistor amplifies the other half (when the voltage goes negative).


I would think that for push-pull, you would want both transistors biased for class B operation (each conducting for exactly 180 degrees of the input signal). But I've also heard people say: "Oh, that guy's amp is operating in class C." It's usually the case though that "that guy's amp" has a transistor pair, which to me says it's push-pull.


So I guess my question is: is it typical to design push-pull amps with something other than class B biasing? Using class AB seems like it would work though you'd lose some efficiency (there would be overlap), but using class C would increase distortion, which is what you're trying to avoid by using push-pull in the first place.


For all I know, it could have been that calling the amp "class C" in that context was just a misguided attempt at trash talk, but I honestly don't know enough about CB amp design to tell if there's any truth to it or not. Do they actually bias push-pull amps for class C (on purpose)? Are they using some other strategy besides push-pull? Inquiring minds want to know. :)


-Bill