[Elecraft] Windom Antennas

Fri Jun 6 12:29:00 2003

In general nearly any horizontally polarized antenna, at nearly any height will outperform multiband verticals. NOT all the time, just so considerably frequently that the joke about verticals is "radiate equally poorly in all directions". 

In typical confined space situations, the ground and clutter situation will absorb much of the power out the feedline, and if not that feedline hookup problems will cause a lot of poorly radiated RF current back along the feedline.

Compared to a vertical over a theoretical perfect ground, losses OVER 10 dB are common. 

This does not occur with horizontal antennas. Often a low angle signal well down the pattern of a horizontal antenna will outdo a low angle signal from a vertical seemingly in the strong part of its pattern, just because the vertical SYSTEM (emphasis on system) is very lossy. 

Windoms have gone into disfavor because of the focus on 50 ohm coaxial feeds. 

For a 100 watt station, running a single wire feed windom (usually 300-500 ohms) down to a 3:1 turns ratio torroid autotransformer to any length of coax from there to the shack will present an impedance completely within the range of the Elecraft autotuners. That's low end to ground rod and coax shield, first turn tap to coax center conductor, third turn tap to the windom feed.

If touching the wire near the ground is an issue, use the center conductor of a piece of coax for the first eight feet going up.

The advantages of this antenna are far less visibility, less weight, very portable, primarily horizontally polarized, and surprisingly multibanded (within the range of the autotuner). 

Just because none of the manufacturers are advertising an antenna, doesn't mean it's not a keeper for a given situation.

I had a multiband vertical that was a killer antenna, but it was over the top of half a block of row house flat copper roofs (!!) with a fairly clear view in all directions. So what made it was not the antenna at all.

The same antenna when moved to my little back yard in the suburbs was a piece of junk. Actually, to be precise, for vertically polarized RF purposes, my back yard was a piece of junk. It was the same antenna.

Hygain mb vert + acre plus of copper-plate roof for ground plane = killer antenna.

Hygain mb vert + 1/4 acre of grass and local clutter = total dud.

Answer to problem: windom @ 20 feet. The off-center twin-lead, heathkit air-wound balun version was all the rage back then. 

73, Guy
K2AV

> 
> From: Phil Wheeler <[email protected]>
> Date: 2003/06/06 Fri AM 10:02:30 EDT
> To: Roy Vickers <[email protected]>
> CC: Elecraft <[email protected]>
> Subject: Re: [Elecraft] Windom Antennas
> 
> Roy Vickers wrote:
> 
> >Last night I worked a station in California using a windom antenna and he
> >blew the socks off my K2. We discussed the Windom and he said it's the only
> >antenna he's used for many years. My poor butternut vertical is almost
> >embarrasing on the air! Of all the stations I heard last night, he was the
> >strongest by far and using 100 watts. I'm sure propagation was helping but
> >other 6 stations were very weak. Anyone on the reflector built a windom,
> >they don't look difficult to build? Found a good website
> >http://www.packetradio.com/windom.htm on how to build one. 
> >
> 
> I used a simple Windom (all wire, no coax nor baluns) back in the 
> fifties with good success (worked the world on 80 and 40 CW with 75W [DC 
> input] from SE Washngton).  The Windom has fallen into disfavor, but I 
> do have good memories of it.
> 
> Phil
> 
> 
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