6M stacked loops - best height above ground?
"Charlie" wrote in message
...
Currently the top loop is at only 20ft but I am making many contacts.
Soon however they will be placed off a sidearm on the tower.
The top loop could then be as high as 80 ft.
I have read and read about this topic. Does anyone have any first hand
knowledge of 6M height above ground comparisons especially for stacked
loops? Thanks....
--
Charlie-AD5TH
First off, what do you mean by LOOP? A Halo kind of antenna, or a vertically
mounted loop? I suspect you mean a Halo (or M2). I ran an EZNEC simulation
on a stacked pair, and it was not great. Minimum stacking distance is a bout
13 feet, with a gain 2db less than a single 3 element beam. Get the bugger
up to 80 feet. A friend of mine had bought 2 M2 loops. Never bothered to put
up the second one when he realized that you can't just stack them 3 feet
apart.
Remember, 20 feet is already a wavelength up. If you really want high angle
radiation, it would have to be a lot lower than that. That will work for E
skip, not very good for F2, or locals. Even at 80 feet, you will still have
multiple lobes, with a good part of the energy going almost straight up.
Tam/WB2TT
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