On Wed, 8 Sep 2004 20:21:46 +0100, "Richard"
wrote:

I know the zeppalin antenna I described works when the top wire is a half
wavelength or greater.

Hi Rich,

You also need to consider the length of the transmission line (what
makes the Zeppelin work with your rig).

I was just wondering if the set up (ie 10 metre
length of top) might at least be a good as a 20 metre long inverted L (well,
L on it's side) on 40, 80 & 160, using a not very good ground arrangement.

For 160 it is quite short, for 80 somewhat short; but being short is
not a sin in and of itself. What is a sin is what the tuner has to
put up with. Most ATU's only cope with up to 3:1 SWR. A short
antenna may well exceed that. Obtain a copy of EZNEC (using the free
version) and give yourself an education on what to expect.

Thing with the zepp is that there is no ground losses. Thing is, ground
losses with inverted L are probably replaced by greater atu losses? And of
course the inverted L would radiate also from the vertical section which
migh be useful. I do wonder of the two arrangements, which would be better.
I wonder also whther I might not get a true balance on the open line when
the top is less than half a wavelength.

You won't have a true balance unless you are feeding a true balanced
antenna (which a Zepp is not, nor an inverted L).

73's
Richard Clark, KB7QHC