In article ,
Ian Jackson wrote:

In message , Billy Burpelson
writes
Ian Jackson wrote:

A typically transmitter is designed to work into a 50 ohm load. This
does not mean that the output impedance is 50 ohms.

Yes, I agree that a transmitter IS designed to work into a 50 ohm load.
However, that would imply that the output impedance would be 50 ohms
also. Otherwise, there would be a mismatch between the transmitter and
the 50 ohm load.

So if you have a transmitter putting out 100W into 50 ohms, how much
power is being lost in the output impedance (=source impedance as far as
the load is concerned)?

If as you say "This does not mean that the output impedance is 50
ohms", please explain what you think the output impedance would/should
be. Or are we getting into some kind of semantics issue?

The effective output impedance is probably quite a bit lower than 50
ohms. If it wasn't, even with the most perfect transmitter, the output
efficiency could never exceed 50%. You would have a very hot TX.

P.S.
Please note that I carefully specified rigs made in the last 20 years
-- those that have a 'fixed' output; i.e. no pi network. Is that what
is causing your confusion?

Do you match the output impedance of you car battery to its load
impedance (or vice versa)?

I can see this is about to get ugly.

--
Telamon
Ventura, California