My experience with 40m vertical dipoles vs. horizontal
dipoles with centers at the same height (50') is that signals
inside of 4-5k miles are down by 4-6 dB. Sometimes more.
Signals beyond that...out around 8-10k miles start coming
up noticeably.
I ran skeds with Hong Kong from NJ, on 40cw both long and
short path, using a vertical dipole, and with a nearby station
using a CC 2 el 40 @ 70'. I was never weaker than he, and usually
3dB or more louder. Into EU, 4k miles away, he was usually
louder by 2dB or perhaps a bit more. Stateside, he'd always
beat me.
It's a tossup...the really long stuff doesn't come through
all that often, so if you can only have one antenna, you need
to decide whether to favor long haul or not.
Jim Lux's comments regarding efficiency and first-reflection
losses are correct. In my view, however, by raising the antenna
higher, you minimize the near field losses, and the first-reflection
losses lie outside your ability to control. (unless you consider
relocation to waterfront property "control".) Bottom line: if
the thing works in your environment, keep it. If not, the alternatives
are a new antenna or a new location.
N2EA
[email protected]
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See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
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