"Gary Morton" wrote in message
...

-- snip --

So perhaps the fact that the transmitter is connected to a 50 ohm load and
the
output transformer is 2:1 turns ratio means that the transistor is
"seeing"
200 ohms?

Exactly.

Nevertheless I am still interested in how to verify that any circuit which
I
design (copy!) does have a 50 ohm output impedance. There must be some way
to
verify this figure.

Please see my reply to Paul Burrage in the next branch over -- hopefully I'm
clarifying that for a power output stage you _don't_ want to see matched
impedances.

For a stage (such as an intermediate, class A stage) where you _do_ want to
verify the output impedance you can either find the resistance _and
reactance_ that maximizes the power output, or you can build an RF impedance
bridge (I use a noise bridge) and measure the stage output impedance
directly. Just don't let it break into oscillation on the output of that
poor impedance bridge!

--Gary