[Elecraft] On ground - in ground radials

[David Gilbert]

"Seems to work".  Sorry, but I don't know what that means. Everything 
works to some degree or other, and unless you are able to do A vs B 
testing, or can take reasonably accurate field strength measurements, 
you don't know what you actually have any more than I know what you have.

I do know that what you have is the equivalent of a single wide buried 
radial.  The whole idea of radials is to act as a near field current 
return to avoid ground losses, and your setup does that in one direction 
only.

I don't mean to make this more than it is, but a Ufer ground is a low 
impedance path for lightning to reduce the chance for lightning to take 
other unwanted paths (such as through equipment or people), and radials 
around a vertical antenna act as an RF shield (or at least alternative) 
to reduce near field ground current return losses.  As I said, they are 
not the same thing.

Dave   AB7E



On 1/16/2022 11:21 AM, jerry wrote:
> Hi Dave,
>
>
> Have you actually tried one?  Mine seems to work.  I was ready to put 
> out radials
> also, but doesn't seem to be necessary.
>
>                  - Jerry KF6VB
>
>
> On 2022-01-16 10:07, David Gilbert wrote:
>> That post illustrates the mistake in thinking that a lightning ground
>> (Ufer) is the same as an RF shield (radials) to avoid ground return
>> losses.  They are NOT the same and they perform completely different
>> functions.
>>
>> 73,
>> Dave   AB7E
>>
>>
>> On 1/16/2022 9:35 AM, jerry wrote:
>>> All,
>>>
>>>    I had a similar situation.  The 4BTV was mounted on a pole 
>>> pounded into
>>> my wildland hill behind the house.  It had about 50 radials, and 
>>> every year
>>> when we whacked the weeds, one or two of the radials would get 
>>> tangled in the
>>> whacker.
>>>
>>>    In the fullness of time, we put in a swimming pool a bit down the 
>>> hill, and
>>> the antenna site became a solar heating field for the pool. The 
>>> concrete guy
>>> poured a 70' by 10' pad for the solar heating array.
>>>
>>>    After he built the forms, I came out with a roll of 8AWG copper 
>>> wire.  I
>>> laid 80 feet of it along the rebar.  I pounded my pipe into the 
>>> earth and had
>>> the wire come out next to it.
>>>
>>>    He poured the concrete, and I had an "Ufer" ground.  I installed 
>>> a brand new
>>> 6BTV, and DX Engineering's tilt base on the pole.  No radials. Works 
>>> great!
>>> I carefully tuned it, and then installed an MFJ998RT KW autotuner at 
>>> the base of the antenna.
>>>
>>>               - Jerry KF6VB
>>
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>
> On 2022-01-16 10:07, David Gilbert wrote:
>> That post illustrates the mistake in thinking that a lightning ground
>> (Ufer) is the same as an RF shield (radials) to avoid ground return
>> losses.  They are NOT the same and they perform completely different
>> functions.
>>
>> 73,
>> Dave   AB7E
>>
>>
>> On 1/16/2022 9:35 AM, jerry wrote:
>>> All,
>>>
>>>    I had a similar situation.  The 4BTV was mounted on a pole 
>>> pounded into
>>> my wildland hill behind the house.  It had about 50 radials, and 
>>> every year
>>> when we whacked the weeds, one or two of the radials would get 
>>> tangled in the
>>> whacker.
>>>
>>>    In the fullness of time, we put in a swimming pool a bit down the 
>>> hill, and
>>> the antenna site became a solar heating field for the pool. The 
>>> concrete guy
>>> poured a 70' by 10' pad for the solar heating array.
>>>
>>>    After he built the forms, I came out with a roll of 8AWG copper 
>>> wire.  I
>>> laid 80 feet of it along the rebar.  I pounded my pipe into the 
>>> earth and had
>>> the wire come out next to it.
>>>
>>>    He poured the concrete, and I had an "Ufer" ground.  I installed 
>>> a brand new
>>> 6BTV, and DX Engineering's tilt base on the pole.  No radials. Works 
>>> great!
>>> I carefully tuned it, and then installed an MFJ998RT KW autotuner at 
>>> the base of the antenna.
>>>
>>>               - Jerry KF6VB
>>
>> ______________________________________________________________
>> Elecraft mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>> Help: http://mailman.qth.net/mmfaq.htm
>> Post: mailto:Elecraft at mailman.qth.net
>>
>> This list hosted by: http://www.qsl.net
>> Please help support this email list: http://www.qsl.net/donate.html
>> Message delivered to jerry at tr2.com