[Antennas] WINDOM

Sun Oct 1 09:26:21 EDT 2006

I guess I should have added that the author of the construction article
claimed the feed point was located at an off center point where the
impedance was 300 ohm, or close to it, on all even harmonically related
bands, hence the 300 ohm feed line. I have no idea if this was true, but
the antenna worked
David
KC2JD
> -----Original Message-----
> From: antennas-bounces at mailman.qth.net
> [mailto:antennas-bounces at mailman.qth.net]On Behalf Of David C. Hallam
> Sent: Sunday, October 01, 2006 9:19 AM
> To: antennas at mailman.qth.net
> Subject: RE: [Antennas] WINDOM
>>> I used a Windom for several years, really an off center fed dipole in my
> case, but not for 160M. Mine was 137 ft long and used KW rated
> 300 ohm twin
> lead to a 4:1 balun then random 75 ohm coax to the transmitter. As I
> remember it came from an article in 1970's Ham Radio. It worked
> on 80, 40,
> 20, and 10. It worked well for me.
>> David
> KC2JD
>> > -----Original Message-----
> > From: antennas-bounces at mailman.qth.net
> > [mailto:antennas-bounces at mailman.qth.net]On Behalf Of David J. Ring, Jr.
> > Sent: Saturday, September 30, 2006 11:31 PM
> > To: Greg Taylor; antennas at mailman.qth.net
> > Subject: Re: [Antennas] WINDOM
> >
> >
> > Unless you're making this antenna of very fine wire, a windom
> > should be able
> > to handle the current - but make sure that the insulators are
> > long enough to
> > handle the high voltage at the ends.
> >
> > The real question is: How are you feeding the antenna so that it
> > presents a
> > good match to a modern transistorized transmitter - which only accept a
> > range of impedances from about 25 to 100 ohms resistive?
> >
> > If you're feeding this antenna using a single wire feeder matched with a
> > Johnson Ranger with a wide range pi-network output which matches
> > 3 to 3,000
> > ohms, you'll have no problem.
> >
> > So the question is what are you going to match the nominal 600
> > ohm impedance
> > with?
> >
> > Also (just to make sure) you are talking about a windom antenna
> > which is a
> > length of horizontal wire which is fed with a single wire feeder
> > off center?
> > Or are you talking about an Off Center Fed dipole - one fellow who makes
> > this calls them "Carolina Windoms" and they're fed with coax and
> > transformers. The Fritzel antenna was one of these - they often
> > can be made
> > to work on many bands - but the limiting factor is the
> > transformers - they
> > have to be built large enough to withstand the voltage and current that
> > accompanies 1,500 watts output. I've also seen coax when subject
> > to a large
> > impedance mismatch fail by perforating the dielectric when running high
> > power. Coax is usually 50 to 100 ohms.
> >
> > 73
> >
> > David N1EA
> >
> >
> > ----- Original Message -----
> > From: "Greg Taylor" <we9m at decaturwb.com>
> > To: <antennas at mailman.qth.net>
> > Sent: Saturday, September 30, 2006 10:21 PM
> > Subject: [Antennas] WINDOM
> >
> >
> > Does anyone on the list know of a 160 meter Windom that will
> handle legal
> > limit? I have never constructed one of these but have built
> several other
> > wire antennas.
> >
> > 73 de WE9M Greg
> >
> > we9m at arrl.net
> > http://users.decaturwb.com/we9m/
> > http://www.qsl.net/kb9kng/index.htm
> >
> > "All that is necessary for the triumph of evil is that good men
> > do nothing."
> > Edmund Burke Irish orator, philosopher, & politician (1729 - 1797)
> >
> >
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