[TowerTalk] 2 antennas

[Jim Lux]

----- Original Message -----
From: "Frank Mayer" <wy3d at usa.com>
To: <towertalk at contesting.com>
Sent: Sunday, April 03, 2005 10:55 AM
Subject: [TowerTalk] 2 antennas


> I had a guy tell me last night that he runs a vertical and a dipole on 80
meters in parallel so he'll get simultaneous horizontal and vertical
polarization.  This sounds like a crazy idea and I believe it won't work,
but exactly why won't it work?
>
> Frank  WY3D

He will get both polarizations, but then, he'd probably get both
polarizations anyway, since most practical antennas for 80m radiate in both
pols due to coupling to adjacent structures and feedlines, etc..  And, of
course, you have no idea what the polarization is for the skyway is anyway,
regardless of what the other end is using (because the ionosphere will
randomize the polarization on a minute to minute basis).

So, the real question comes down to efficiency... In general, horizontal
antennas for 80m have higher electrical efficiency than vertical antennas
(in a watts radiated into the far field vs watts fed into the feedline).
This is important for Tx, if you're power limited.  Not so important for Rx,
where sensitivity to local noise sources might result in a preference for
one polarization or the other (or, more realistically, the actual pattern of
the two antennas is probably different in "fine scale" details).