[TenTec] OT Antenna Tuners

[Dr. Gerald N. Johnson]

On Sat, 2008-07-19 at 05:41 -0700, Jim WA9YSD wrote:
> Interesting what it says is this publication   http://www.somis.org/bbat.html
> 
> He tells about the Sham of baluns and fully supports current baluns.
> 
> Does not mention L networks as to why it will not give you the improper Q match like some tuners do with a 1:1 SWR.  Or did I miss that?
> 
> Keep The Faith, Jim K9TF/WA9YSD
> 
> 
>       
While his understanding of impedance matching and filtering networks is
a little off the wall, the concept of a balanced tuner with the balun at
the 50 ohm side is a good one that keeps from abusing the balun to get
excess balun losses or harmonic generation from saturating the core. And
as a practical matter, the balanced tuner beyond the balun works quite 
well even if not physically balanced.

Many years ago in an AC circuits class talking about pi networks as
filters, I asked the grad assistant about impedance matching with pi
networks. He'd never heard of such a thing. So the concepts can be a bit
different. After a few years in high power transmitters, I learned much
about impedance matching and loaded Qs. There are short cuts, but
sometimes they are shorted and have to be understood to know when they
are wrong.

73, Jerry, K0CQ