[Antennas] Vertical

Sun Nov 27 20:48:17 EST 2005

Well a couple of things Mel...
[advertisement!] My company makes a patented machine specifically for 
burying radials... Its patterned after a single-bottom plow that you pull 
behind a tractor. We make several models, but I can tell you that the 
machine will put radials into just about any surface except solid rock. By 
accident I ran our prototype a little farther than I should have, and now he 
has at least one radial buried four inches below his asphalt driveway. We 
custom make them for just about any tractor... our standard fits a 3-point 
hitch on a small compact 22 hp 4WD Kubota that is more than adequate for 
putting down radials in the hardest soil up to 150% of normal compaction. 
We sell these, and we even have a couple models that we RENT by the day. I 
put down 225 radials beneath my own vertical in the back yard... 130 feet 
long... in less than an afternoon.
If anyone tells you how many radials you need (10, 50, 100, 200, etc.) for 
your antenna system... they don't have a clear grasp of all the parameters 
that impact the radial system. The ONLY reliable way we have found to 
determine the number of radials that are useful given soil conductivity, 
frequency, depth, orientation, length, and other parameters that impact 
electric field density is to simply plot the frequency dependent impedance 
while adding radials. When you nolonger see a change in the impedance as 
radials are added at the lowest frequency of operation... you can safely 
assume that, without changing any other parameters (like increasing radial 
length) that you have reached the point of no return. This follows the 
George Brown's original findings.
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
"It's not what you take with you... but what you leave behind that counts. 
Live each day as if it were your last."
----- Original Message ----- 
From: "Mel Vance" <icra at galaxynet.com>
To: <antennas at mailman.qth.net>
Sent: Saturday, November 26, 2005 11:37 PM
Subject: Re: [Antennas] Vertical
>> Yeah leave the "salt" for your thanksgiving dinner and use a real
>> engineering solution here... That is unfounded witchcraft. Elevated
>> radials are great if you have the space for them (read that: get them
>> far enough off the ground that you won't trip over them/ behead
>> yourself/ they don't get caught in the mower/ etc.)... Of course 200+
>> buried radials works too (hundreds of AM stations can't be wrong!).
>>> But, there are some of us that can not use either buried radials or 
> elevated
> radials.....
>> So, what would you suggest I do to get something resembling a ground in 
> very
> heavy clay soil? Not being sarcastic....really need to get a better RF 
> ground on my
> station.
>> Soil around here is glacial deposit....very heavy clay content and lots of 
> rocks....took
> me a little over 2 years of pounding with a sledge hammer to drive 6 feet 
> of a 10
> foot ground rod....will not go in any more and can not pull it out. Even 
> 15 4-foot
> ground rods connected together is not giving me a reasonable RF ground.
>> Any ideas on how to improve the grounding situation? Besides 
> moving.....wish that
> was a viable option, but the bank account has vetoed that one.....
>> Mel
> N7OKL
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