[Elecraft] AX1 works great

[Jim Brown]

On 9/30/2024 1:39 PM, Rick nk7i wrote:
> In the simplest sense, what a tuner does, is (attempt to) adapt the 
> impedance of the antenna to that of the source so that the max energy is 
> exchanged between the two (what works for TX, works for RX).

Hi Rick,

I disagree with this analysis and that proposed by AB7E, primarily 
because it ignores the match between the antenna feedpoint Z and the 
transmission line, which is what determines voltage and current 
distribution along the line, and its loss. The tuner does NOT change that.

What a tuner does is transform the antenna's impedance as seen at the 
shack end of the line to a value that the transmitter's output stage can 
supply power and operate optimally. For most modern transmitters and 
solid state amps, that's 50 ohms resistive.

Those of us long enough in the tooth to remember hollow-state amplifiers 
and output stages may have learned that they come equipped with variably 
tuned output networks to do what antenna tuners do, but usually over a 
much less-wide range.  My Ten Tec Titan 425, 1978 vintage, could be 
happy with mismatches in the range of 3:1. Ten Tec sold one of the best 
(greater efficiency over a wider range) tuners to cover a much wider range.

BTW -- I know that you know all this stuff -- this post is for those who 
don't. :)

73, Jim K9YC