I put up an, as long as possible, wire between two trees. I feed it 1/3
from one end with a ladder line I built myself. The ladder is made of #14
wire, 4 " apart. I use LEXAN as insulators 9 " spacing. I feed the ladder line
with a LC tuner (that I also built myself). The tuner is connected to the
trx via a choke made of RG58 would around a 4" schedule 40 about 8" long.
The windings are tight in one end to gradually separate at the other end.
That way you get a better bandwidth on the choke.
My wire happen to be about 240 feet long and works good on 160 - 10 meter,
but I am sure you can be successful with a shorter wire.
The impedance in your 40 meter dipole has a very high impedance at 20 meter
which gives you a high SWR and following losses. My son discovered that
when he erected a 33 foot vertical. It worked great on 40 and 15 but not at
20 until he followed my advice to put a tuner next to the vertical and tune
it when he worked 20 meter. You will have a similar problem at 20 as well.
A ladder and tuner will improve you 40 m dipole on 20.
Good luck and 73 de,
Hans - N2JFS
> -----Original Message----- From: Dick NY1E
> Sent: Tuesday, January 31, 2017 6:51 PM
> To: towertalk@contesting.com
> Subject: [TowerTalk] 40-10 meter wire antenna
>
> I'm in a limited space location, I'm looking for a wire antenna to use
> on 40-10 meters. The handbook says a 40m dipole fed with ladder line
> will be 2 half waves in phase on 20, and have 1.8 db gain. My coax fed
> 20m dipole is 10db better than my coax fed 40m dipole on 20, will open
> wire feeders and a tuner really improve it that much?de Dick NY1E
>
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