Here is an article by K5IU that talks about shortened elevated radials.
Optimal Elevated Radial Vertical Antennas
<https://nonstopsystems.com/radio/pdf-ant/article-ant-5IU-97.pdf>
Hope that helps.
73, Glenn KD0Q
On Mon, Mar 15, 2021 at 2:55 PM N4ZR <n4zr@comcast.net> wrote:
> 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
> Check out the new Reverse Beacon Network
> web server at <http://beta.reversebeacon.net>.
> For spots, please use your favorite
> "retail" DX cluster.
>
> 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@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@gmail.com>
> >> To: "kj6y--- via TowerTalk" <towertalk@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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> >>
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