David L. Foreman
davelf11 at cox.net
Thu May 10 17:49:02 EDT 2007
Good afternoon, Dan.
The Gap Challenger Multiband DX antenna that the OPRC has or had available, uses three counter poise wires and from reading the manual,
and my emails with Gap, are buried just like radials, although you could elevate them with the antenna.
The person the answered my email to Gap asked my why I wanted to elevate the eitire antenna and counter poise system.
Below is what Gap says about the antenna.
CQ tested the Challenger and established that on 2m, for example, its gain was approximately 6 to 8dB. On 40m compared to a mono band vertical, they found Challenger an S unit stronger. This is typical of the many reports received from amateurs around the world. Challenger is designed to be mounted directly in the ground or elevated. A ground mount is provided with each antenna. With the ground mount in place, the Challenger simply drops in. If necessary, because of space limitations, but not to improve performance, Challenger may be roof mounted since it does not require earth loss to obtain a 50 ohm match. Challenger requires a counter poise of three 25ft. insulated wires. They may be buried or just scattered on the ground. Symmetrical deployment is not critical. Adding additional wire will not significantly improve performance. All of these are covered in a 16-page assembly manual provided with each antenna.
----- Original Message -----
From: "KC7VDA" <KC7VDA at keepandbeararms.com>
To: <antennaware at contesting.com>
Sent: Thursday, May 10, 2007 13:06
Subject: Re: [Antennaware] radials
> -----Original message-----
>> Today's Topics:
>> 1. Re: homemade coil (Andrew Ingraham)
> Hello All;
> If you will pardon a newcomer ( to your group) for poking his " beazer" into
> what appears to be an ongoing argument, an argument that I am sure will continue
> as long as there are Hams and antennas, I have a few questions and a comment
> or two.
> First a question and a comment, an unkown writter makes the statement:
>> > with poor reports, running 600 watts. I worked US hams at about 200
>> > miles with good reports. However, I think that I can lay much of the
>> > blame for the reports on the fact that I have a single radial, slightly
>> > shorter than 1/4-wavelength. Once I establish a good mechanical
>> > connection and a reasonable SWR, I will add radials (aiming for 60) and
> Does he really mean a radial or a counterpoise?
> if he really means a counterpoise, would the addition of radials really do any
> good? I am under the impression that radials were not needed where a counter-
> poise is used, that the counterpoise served the same perpose.
>> I have no personal experience with verticals (aside from engineering at AM
>> radio stations long ago), but from what I've read elsewhere, even a single
>> radial is OK *as long as it is not buried* or on/close to the ground.
> I too have served my time working with AM stations, the vertical of my station
> was surrounded by 160 radials that, after the first few feet, were burried under
> egg sized rocks.
> However,when working with Ham Band verticals, I have been under the
> impression that a minimum of 4 radial, each 1/4 wave length of the lowest
> frequency to be used was a necessity. ( and yes, I understand that more is
> usually better, up to a certain point, ) Am I wrong about the length or does it
> matter ?
>> Elevated above ground, it's a counterpoise, you want it to be a quarter
>> wavelength long, and you need only one (though having only one might make
>> the antenna a little directional). But once it's coupled to the ground, the
>> soil detunes it and ground losses go way up ... unless you've got a lot of
> My experience here in Tucson, Arizona has been that burying radials up to 4
> inches below ground doesn't make any difference, I belive that the dry nature
> of the local soil to be responsible for the low losses.
>> So to improve your signal, you could either run your single radial elevated
>> above ground, or bury 60 of them.
>> The nice thing about buried radials, is that they can be shorter (about 0.1
>> wavelength) and they don't need to be tuned.
> Yes, I fully agree, run as many radials as you can, make them as long as you possibly
> can, keep them, preferably, above ground but bury them if you must, and you will
> definitely improve your signal .
> To my way of thinking, the only thing that improves a good ( maybe a great ) antenna
> system is a good radial and ground system.
> My only other comment would be that the radials don't have to be run in a perfectly
> straight line, the wires composing your radial system can be moved around as needed
> to clear obstructions ( read that as your better halfs Roses, Mom's Petunias, the side-
> walk or Juniors swing set, sandbox etcettra) . If that obsticle is a beautiful yard full of
> grass that you are understandably reluctant to dig up, the solution is to beg, borrow or
> otherwise scrounge a side walk trimmer. With it you can easily make very nice, narrow,
> cuts in the grass, without any dirt being thrown up on the grass. You then simply stuff
> the radial wire into the cut you just made and when you next water the grass the cuts
> will disappear.
> O.K. thats my 2 bits worth, and should add a little more fuel to the fire, if I have said
> anything that you disagree with I am certain you will let me know and I look forward
> to hearing it.
> 73 de kc7vda (Dan)
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