Re: [Practical Question] Antenna Shorteners

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From: Ade Weiss W0RSP (adeweiss@sd.value.net)
Date: Wed Dec 04 2002 - 23:38:31 CST


I want to second Dr. Mega. on this one. I'm using my 30m dipoles on 40m. EZNEC
shows very little diff. in gain on 40m vs 30m. The patterns are slightly less well
defined fig-8's, but in reality, given all the metal in my fresnel environment, the
actual patterns are not perfect. However, the directionality on 40m is what
one would expect from a dipole. I'm at 80 countries on 40m mainly during contests
although I've had several QSY down from 30m DX requests from Oceana and Eu.
and made successful QSO's. The dipoles work quite well on 20-10m as well. I feed
both with "opened" 300-ohm ladderline. If you ever compared 300-Ohm and 450-Ohm
ladderline -- at least the brands I've seen -- the openings in the 300-Ohm variety are
alternating long and short while they're all the same size in 450 stuff. It took a while,
but I made them all long to reduce wind resistance. I just cut with a standard orange razor
box cutter.

In my opinion, you just can't beat a dipole even if it is short, like a 30m dipole on 40m.
I've never tried it on 80 -- maybe I should.

72, Ade

>>>Brian - If I were you, I would stick with the 30 M dipole length and feed it
with ladder line and a tuner to use on all bands. The perfromancce fall off
on 40 M compared to a shortened 40 M dipole will be negligible. You will be
able to use the antenna on all bands from 40 M up. - Dr. Megacycle KK6MC/5

--
James R. Duffey KK6MC/5
Cedar Crest, NM   DM65


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