aunwin wrote:
Can't we assume that a antenna is a closed series
circuit containing only passive items ?

A passive antenna, when it is receiving a signal, is a pretty good
approximation to a Thevenin Equivalent circuit. The received
signal is the generator. The generator impedance is the radiation
resistance (and the lossy R's). We've got a transmission line and
usually a 50 ohm load in the receiver.

If you have in mind that we must we consider an antena as a Class
something or other amplifier when determining its impedance then I am
hopelessly lost in a thread that can only end up nasty like some others did

Why not, for the purposes of limiting the discussion, consider only
a Thevenin Equivalent 50 ohm source for the transmitter? That way,
the entire system will be linear and easy to discuss.

I am not pointing the finger at you Cecil, ...

If you were, which one would it be? :-)
--
73, Cecil, W5DXP