[TowerTalk] The Care and feeding of an 80 meter Zepp

[Jim Lux]

At 08:17 AM 3/28/2005, Tom Rauch wrote:
>Ohh, OK, a shunt C. I missed that. My instincts tell me we
>have to be careful with a shunt C when the network has a
>series C in the output, like a T network. But maybe I'm
>wrong.

Most autotuners (or, at least, the SGC and LDG varieties) seem to use a 
shunt C and a series L, with the shunt C switched to either end, depending 
on the relative magnitude of the feedpoint impedance of the antenna being 
matched.



> > Maybe I wasn't clear here either:  "drop the counterpoise"
> > does not mean "omit the counterpoise".  It means connect
> > a wire to the cold end of the counterpoise and let it drop
> > vertically from there to the ground.  BTW, when your
> > antenna impedance is 1000's of ohms, you don't need much
> > of a counterpoise, especially if you feed the
>antenna/counterpoise
> > through a balun to keep RF out of the shack.