[Elecraft] Counterpoise vs ground wire ?

[Don Wilhelm]

The "classic zepp" antenna lives on in VHF circles, and is known as a 
J-Pole.  Turn the Zepp vertically and you have a J-pole.  The major 
difference is the J-pole feed - the 1/4 wave transmission line section 
is shorted at the bottom and teh 50 ohm feedline is connected up a bit 
where the impedance is 50 ohms.

73,
Don W3FPR

On 7/1/2012 5:40 PM, Ron D'Eau Claire wrote:
> That was the beauty of the Zeppelin antenna (the true "Zepp") A half wave
> radiator is end fed through 1/4 wavelength of open wire line. One side of
> the line connected to the radiator and  the other side connected to nothing
> - just an insulator. Since very little current flows at the feed point, the
> balance in the line is still good. The 1/4 wavelength of line converted the
> high impedance at the radiator to a low impedance at the rig. Of course
> that's only true at one frequency for a given length of radiator and feed
> line.
>
>