[TowerTalk] high power tuners

[Jim Jarvis]

FWIW, at my MD site, I wanted to have a general purpose utility
antenna.  Aesthetics played a part.  

Put up an 80m dipole fed with open wire line....perhaps 100' of it.
Bought a Tentec 238B tuner.  Nice tuner...second one I've owned.
(much better without the dial cord!)  

First time I've tried the 238 with OWL.  First time I put power into
it on 40, I saturated the balun core....man, did that smell hot!  

Let's see....40m full wave, center fed....2000 ohms, fed about a 
wavelength away on the OWL...1200 watts... can we say high voltage?  
The short form is, the 238 is NOT a high power tuner for balanced
wire, under all conditions.

Model the driving point impedances on various frequencies, and you'll
quickly see that the wide range of situations requires extreme caution
in design.  Radioworks won't sell their 'remote balun' without a serious 
caveat, for the same reason.    

The short form of this is, you're going to have to model what you want
to do, and make sure you can handle the wide range of complex impedances
you'll see.  When you turn the wick up on that amp....you'll find the
weakest link, for sure.

Jim/n2ea