OK will do some ck'ing.
Hey whille we are on antenna's...
Someone know where I can find some info . I am looking to put my 5/8 wave
10 meter gound plane above my TA 33m Mosley. And I dont want it reduceing
gain as much as possable.
NOW I built this 5/8 wave 10 meter antenna. So I was going to remove the
radials. Hopeing this would help protect the beam. And then let the beam act
as a conterpose/ radials . Now I had heard that just less than 1/8 wave was
best. Between the vertical and the beam .
But I was looking for info. And so far am not finding any. I have only one
antenna tower and rent. So I have to put them on the same one. And we have a
local net on friday night . And a group of us met on 28.430 almost every
night. So I must keep the Vertical. Given time I could find this. But I may
get more input here.
Thanks
Derwin
----- Original Message -----
From: "Billy Cox" <aa4nu@ix.netcom.com>
To: "Discussion of Ten-Tec Equipment" <tentec@contesting.com>
Sent: Saturday, August 16, 2008 12:57 PM
Subject: Re: [TenTec] OT: Ground Radials at Tower Base
> 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
>>>
>>> _______________________________________________
>>> TenTec mailing list
>>> TenTec@contesting.com
>>> http://lists.contesting.com/mailman/listinfo/tentec
>>
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