[time-nuts] TNS-BUF update

[Richard (Rick) Karlquist]

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