I was reverse engineering the circuit so I could verify that the high power transistors are used in the amplifier, and the low power ones are bias controllers. The bias circuit resembles the ones used for applications where the transistor's emitter is connected directly to ground to reduce parasitic inductance at microwave frequencies. But this is 10 MHz and in any event, there is a 68 ohm unbypassed emitter resistor, which I assume is there to reduce flicker noise, which is indeed very low.
Anyway, since there is this 68 ohm resistor, I don't see why it isn't sufficient to simply connect a fixed bias of about 1V to the base. You could even temperature compensate the voltage with a temperature sensing diode to cancel out drift of the base-emitter voltage. I'm not saying the circuit won't work, I just suggesting it is needlessly complicated. Can anyone clarify this? Can I make a high power version of this by simply changing to 2N3566/2N5109/2N5943, etc. transistors? Is the transformer feedback a poor man's Norton amplifier scheme? Rick N6RK _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
