[Antennas] windom coaxial connection

[Charles Greene]

Alex,

Not to split hairs, but the ARRL antenna handbook recommends 136'.  I have 
used 135' as both modelling and practice show the antenna is resonant on 
80, 40, 20,  18, 12 and 10 meters.  A few feet doesn't make much difference 
on 80 meters, but it will put you right out of the band on 18 and 12 
meters.  I use a 4:1 balun at the antenna; either a heavy one at the 
support or a very light one < one oz. at the antenna.  That works better 
than a 300 ohm ladder line feeder with a balun at the ground level.

At 04:21 PM 3/26/2005, Alex Eban wrote:
>The offset feed dipole, misnamed Windom, has well defined dimensions:
>regular  half wave at the lowest operating frequency! What makes it special
>is that it operates quite well on even harmonics, unlike the classic dipole.
>In any case the multiband version should be about 130 ft. the feed point
>should be 33% of the antenna's end and the impedance is somewhere from 200
>to 400 ohms on the various bands. Hence, a 4:1 balun would do good from the
>impedance matching point of view, as well as from the from the elimination
>of RF on the cable angle. BTW this variant is known also as the FD4 antenna
>and I have quite well written  article on it, if you want it.
>         Alex    4Z5KS
>
>-----Original Message-----
>From: antennas-bounces at mailman.qth.net
>[mailto:antennas-bounces at mailman.qth.net] On Behalf Of Harvey&Bessie
>Sent: Monday, March 28, 2005 11:42 PM
>To: Patrick O'Brien
>Cc: antennas at mailman.qth.net
>Subject: Re: [Antennas] windom coaxial connection
>
>The original Windom antenna was a half-wavelength wire with a single-wire
>feeder tapped 12 to 14 % off the center. Then somebody came up with a
>half-wave antenna fed with two wire feeder (open-wire) tapped that same
>distance off center and called it a California Windom.
>   I suppose you could use co-ax at that feed point. The coiled coax acts as
>a balun to prevent rf current from running down the outside the outer
>conductor of the coax.  You probably paid too much for 66 feet of wire?
>Harvey/W4TG
>
>
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73,  Chas,  W1CG