[Elecraft] grounding and counterpoise - Zepp

[Mike Morrow]

Ron wrote:

>... the most famous "aircraft" antenna is the Zeppelin antenna...
>balanced feeders from the transmitter to the END of a 1/2 wave
>antenna. At the antenna, one feeder connected to the end of the
>radiator and the other feeder simply stopped at an insulator...

>Most Ham "Zepps" today are not like the original Zeppelin antenna

The common VHF/UHF "J-pole" antenna is the most commonly encountered Zepp
antenna used by hams today.  The J-pole has every characteristic of the HF
wire version, except that it is usually stiff and vertical, and the coax
section is usually attached mid-section in the matching section.

Moxon's "HF Antennas For All Locations" book, pages 47 to 49, has some
interesting and convincing observations on the Zepp which conclude that it
should NOT work either theoretically or practically as it is typically
depicted, were it not for the effect of stray capacitances to ground and
between conductors in the matching section.

73,
Mike / KK5F