[Antennas] ground mounted vertical radials question

Tue Nov 14 23:54:41 EST 2006

<<Using more than 16 radials does not help much.>>
Prove this.... Show me mathematically how this makes any sense.
Sincerely,
Dr. William J. Schmidt, II K9HZ
Trustee of the North American QRO - Central Division Club - K9ZC
Email: bill at wjschmidt.com
WebPage: www.wjschmidt.com
"If you drink... don't drive. Don't even putt" - Dean Martin.
----- Original Message ----- 
From: "Charles Greene" <crgreene at cox.net>
To: "David Ashworth" <fathom at dslextreme.com>; <antennas at mailman.qth.net>
Sent: Tuesday, November 14, 2006 8:34 PM
Subject: Re: [Antennas] ground mounted vertical radials question
> David,
>> The best approach is to go for more radials on the order of 0.1 wavelength 
> rather than less radials that are longer. I have a Hustler 6BTV and I 
> put 2 radials for each band about a 1/4 wave length each; however, that 
> was several years ago and I'm smarter now. So if a radial is 0.1 
> wavelength on 80, it is 0.2 wavelength on 40, 0.4 wavelength on 20 and so 
> on so it is an effective length on all bands. The reason for this is that 
> current in the ground radial drops off over 0.1 wavelength so making the 
> wire longer is not necessary, but the longer wire does not degrade the 
> effect of the radial, so the longer wires are still an effective length. 
> You would think 1/2 wavelength would not be a good length as it would ofer 
> a high impedance at the antenna, but looking at the current that is not 
> the case. Using more than 16 radials does not help much. In other words, 
> 32 radials marginally better than 16, but not twice as good.
>>> 73, Chas W1CG
>> At 12:37 AM 11/11/2006, David Ashworth wrote:
>>Hello to all. Will be installing a Hustler 5BTV vertical on the ground, 
>>up
>>in the country where there is no problem with people tripping over 
>>radials.
>>The radials will NOT be buried. They will be placed upon the ground. 
>>Been
>>reading my reference material on radials, but would like to hear from
>>operators that have been there/done that. The lowest band will be 80 
>>meters
>>and the highest 10 meters. Hustler recommends at least two radials per
>>band. Then, been reading W2FMI's book about short verticals. Think he 
>>was
>>happy with about 40 radials. Am I on the right track, the more radials, 
>>the
>>better, up to a certain point? The soil there is very dry unless it has
>>been raining. As soon as the sun comes out, there goes the moisture 
>>content
>>of the soil. So, would it be better to spread, say 40 radials at 1/8
>>wavelength, or maybe 20 at 1/4 wavelength? Would you spread some for just
>>80, or do a combination of the different bands? If this was salt water, 
>>bet
>>you could throw a coat hanger in there, but it is not. Any good ideas? I
>>am leaning towards less radials and longer radials, but experience is the
>>best teacher. Thank you for your comments/recommendations, Dave, NC6P.
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