[TowerTalk] Vertical question

[N4ZR]

This is the second allusion to 1/8 wave elevated radials that I've read, 
but I've been unable to find anything further, in the usual sources.  
Any leads?  I have an inverted L, but really don't have room for 1/4 
wave elevated radials and am told that my 8 x 70 foot radials on the 
ground really aren't worth much.

73, Pete N4ZR
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On 3/15/2021 3:00 PM, Ignacy Misztal wrote:
> My feeling is that modeling with verticals is less than perfect or perhaps
> the interpretation of results from modeling is imperfect.
>
> In 160m contests we hear signals that are poor, OK and spectacular. In
> cases I know, those OK have 30 radials and those spectacular have 100
> radials. While the maximum angle radiation may be affected by < 1 db,
> perhaps low angle radiation may be affected by 10db or more.
>
> I had an inverted L with up 80 feet with 4 elevated and tuned radials. Then
> a shunt fed a 100ft tower with 16 upgraded later to 36 radials.  Modeling
> indicated little difference. When tested by RBN, the tower was 6 db better
> with 16 radials and 8 db better with 36. Well worth the effort.
>
> I used to have an inv L with a few 70 ft elevated radials used for both
> 160m and 80m. The performance was OK on 160m and pathetic on 80m. There are
> papers showing that 4 1/8 wave radials on the ground are better than 4 1/4
> wave radials.  Perhaps this applies to low elevated radials. Verticals with
> short radials need a transformer, not a  balun.
>
> Ignacy NO9E
>
> On Mon, Mar 15, 2021 at 11:58 AM Patrick Greenlee <patrick_g at windstream.net>
> wrote:
>
>> What comes to mind is how true to reality is the model's results?  If
>> the model is relatively true to reality then most of us would likely not
>> bother with additional radials.
>>
>> You said, "It is working great."  Is that a reasonable motivation to add
>> 4 more radials to maybe get 0.01 more dBi?  The term diminishing returns
>> comes to mind.
>>
>> I would suggest leaving it alone and enjoy using it.
>>
>> Have fun.
>> Patrick       NJ5G
>> .
>>
>> ------ Original Message ------
>> From: "Dave Sublette" <k4to.dave at gmail.com>
>> To: "kj6y--- via TowerTalk" <towertalk at contesting.com>
>> Sent: 3/15/2021 10:26:00 AM
>> Subject: [TowerTalk] Vertical question
>>
>>> Good morning,
>>>
>>> I recently changed my elevated 160 meter quarter wave vertical with 8 full
>>> sized radials to having only 1/8th wave length radials and only four of
>>> them.  It is working great.  So I thought adding four more radials might
>>> improve things.
>>>
>>> But before I went to all the trouble I decided to model it and see if
>> there
>>> was a difference in performance of the 8 radial version compared to the 4
>>> radial system.
>>>
>>> I use a modelling program called Antenna Model.  The result of the
>>> comparison is this:
>>>
>>> The 4 radial system showed a gain of 0.92 dBi with the main lobe at an
>>> elevation of 20 degrees.
>>>
>>> The 8 radial system showed a gain of 0.93 dBi and an identical elevation
>>> pattern.
>>>
>>> My question is:  Why is the gain figure so low?  A dipole exhibits 2.14
>> dBi
>>> gain. Why doesn't the vertical show gain?
>>>
>>> And lastly, I think these results tell me it isn't worth the effort to add
>>> four more radials.
>>>
>>> Your thoughts?
>>>
>>> Thanks & 73,
>>>
>>> Dave, K4TO
>>> _______________________________________________
>>>
>>>
>>>
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