[Elecraft] Antenna tuners

[David Gilbert]

That's not in the least true, but those among us fixated on semantics 
continue to push that tired old myth.

You could, for example, have an antenna with a feedpoint impedance of 50 
- j40 ohms, and if you insert 40 ohms worth of inductance in series with 
the feedline at the feedpoint you will TUNE that antenna to resonance 
exactly the same as if you put an appropriate amount of reactance in the 
antenna itself or adjust its length ... all of which do exactly the same 
thing.  The antenna and it's feedline are inseparable as far as the 
overall network is concerned.  One is not independent of the other ... 
ever.

Furthermore, the adjustment (i.e., "tuning") can be done at the shack 
end of the feedline with EXACTLY the same effect except for the 
transmission line transformation by the feedline, and of course its 
associated loss, since whatever is done at the shack end is reflected 
back to the antenna end.

Yours is really a very tedious distinction that has no basis in actual 
physics or network theory.

73,
Dave   AB7E



On 7/17/2020 6:59 PM, Fred Jensen wrote:
> No antenna has, at any time, anywhere in any of our lifetimes, been 
> "tuned" by an "antenna tuner."  So called antenna tuners are 2-port 
> impedance matching networks ... all of them ... and their job is to 
> match the impedance on one port to another impedance on the second 
> port, period.  Nothing gets "tuned."  They come in a variety of 
> flavors ... a pair of push-pull 807's with a resonant tank and a link 
> feed to the antenna on open wire line is one. Everything that happens 
> on the feed line [regardless of it's construction] is the sole result 
> of the complex impedance at the antenna feed point and the 
> characteristic impedance of the feedline.  No magic.
>
> 73,
> Fred ["Skip"] K6DGW
> "Captain Obvious"
> Sparks NV DM09dn
> Washoe County