Sadly Derwin, you are very "missaken". Do a search
on W8JI, or read ON4UN's Low band DXing books to
learn how ground system really work.
There is "no free lunch" with radial systems.
73 de Billy, AA4NU
-----Original Message-----
>From: Derwin Goliver <dgoliver001@woh.rr.com>
>Sent: Aug 16, 2008 12:52 PM
>To: geraldj@storm.weather.net, Discussion of Ten-Tec Equipment
><tentec@contesting.com>
>Subject: Re: [TenTec] OT: Ground Radials at Tower Base
>
>Well now....
>As far as radials go. I like to mount my verticals off the ground.
>Becouse just a few 1/8 wave off the ground. Is better than many in the
>ground.
>If I am not missaken. Some thing like 2 1/8 wave off the ground = something
>like100 in the ground.
>I have a 5/8 wave 20 meter vertical with 3 off the ground (gound plane
>style) . Thas I made this antenna is smoken' .
>I mounted it on the garage roof in a tri pod. With 3 14 foot radials and a
>matching coil at the base.
>Thing is this needs guys. Becouse of its 41 1/2 foot heighth .
>
>Derwin
>
>
>----- Original Message -----
>From: "Dr. Gerald N. Johnson" <geraldj@storm.weather.net>
>To: <tentec@contesting.com>
>Sent: Friday, August 15, 2008 10:40 PM
>Subject: Re: [TenTec] OT: Ground Radials at Tower Base
>
>
>> On Fri, 2008-08-15 at 19:46 -0400, Gary Hoffman wrote:
>>> If you improve your grounding system, you will always be happy that you
>>> did.
>>>
>>> To say it will or will not reduce noise requires knowing a lot more about
>>> the specific details of your setup.
>>
>> The grounding system for a vertical antenna is often deficient. That's
>> easily seen when the antenna SWR is low, but there's no matching
>> network. The perfectly grounded vertical should have a feed point about
>> 35 ohms. If the number of radials and ground rods is small, they can
>> contribute resistance to the feed point impedance raising it towards 50
>> ohms for a better apparent match. But with the radiation resistance 35
>> ohms and the ground resistance contributing half that much, the antenna
>> efficiency is 2/3 what it ought to be for both radiation and reception.
>> So improving the vertical antenna grounding (more radials, 50 is a
>> start, 256 is considered enough in broadcast circles, and more rods)
>> hurts the match but improves the antenna efficiency. That may actually
>> increase the noise heard, but it will increase DX signals by the same
>> amount so ought to be a wash. Unless a radial happens to contact a
>> ground from a noisy power pole.
>>>
>>> If there are grounding issues (and maybe there are not) and you fix them,
>>> it
>>> can certainly help.
>>>
>> The good noise reception on a vertical is why some 80 and 160 meter
>> DXers use a loop or Beverage for reception (directivity, not efficiency
>> is the goal) and the vertical only for transmission. Its hard to beat a
>> vertical for low angle (and thus best DX) radiation and reception, but
>> the propensity of a vertical to hear in all directions makes it hard
>> without going to an array of verticals to hear the weakest of signals
>> over the noise. Even atmospheric noise can be directional, so a
>> directional receiving antenna can be a benefit.
>>
>> 73, Jerry, K0CQ
>>
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>
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