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Old December 27th 04, 09:08 PM
Bart Rowlett
 
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Verizon News wrote:
Sure looks complex for a circuit that only delivers 10W and 10dB gain at 14
MHz. Also, the common-collector configuration ("emitter follower") is
notorious for becoming an oscillator when driving reactive loads.


It's not actually common-collector. The input is applied between the
base and emitter, and the output extracted between the emitter (ignoring
ballast resistors) and collector. It's an ordinary common emitter
amplifier but with the collector grounded.

Unlike the emitter follower, which is almost guaranteed to become
unstable with sufficiently large capacitive loads, this circuit is
devoid of feedback external to the transistor. The circuit should be
fairly stable assuming the tank circuit is well behaved at all
frequencies up to the transistor Fc.

What's the advantage of this circuit supposed to be?


Insulator between collector and heatsink is unnecessary.

bart
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