I don’t think you are going to find a “book” solution for what you are
trying to do. Almost anything will work, but some layouts will work better
than others. Since you don’t really have any choice, go ahead with
installing it and then “tune” it by adjusting the radial lengths.
I would start by installing the vertical and the radials for the lowest
band. They need to be adjusted first because they will have a huge effect
on the tuning of the higher bands.
Set the vertical for the center frequency you want on that band then
connect one of the radials and adjust for the lowest SWR. Then disconnect
it and connect the other one and adjust for lowest SWR. Then attach them
both and check the SWR (Note: Many times on the lower bands the usable
bandwidth is very narrow. Sometimes turning for a slightly higher bandwidth
might give a slightly wider usable bandwidth)
Then, leaving the lower band(s) radials connected, repeat this process on
the next higher band and so forth until you get to the highest frequency
band.
Likely, you will have to go back to the lowest band and make slight
adjustments.
If you have any questions, email me.
Good luck and good DX,
Chuck W5PR
On Fri, Oct 24, 2025 at 6:07 PM Dale Dean <browndog2344@gmail.com> wrote:
> I have a SteppIR BigIR vertical that I am refurbishing. It will be
> installed in a small backyard that does not allow for the normal ground
> radial system (such as 60 ea at 33'). I will need to go to 2 ea tuned
> elevated radials for each band (80 thru 10 - 8 bands). My solution (I
> think the only one I have due to lot restrictions) is to run the radials
> along the vinyl fence. The vertical is mounted on a 4x4 post at 5 feet
> above the ground. One direction has about 70' of length (straight) but the
> other direction has a 90-degree turn about 20 feet down from the antenna
> and then a straight shot the rest of the lengths so the radials for 80, 40,
> and 30 will have a 90-degree bend at that point and then continue on
> straight. All the radials will follow the fence line so they will not be
> spaced out is a circular distribution from the antenna. There will be
> about 1 to 2 feet of horizonal spacing in the plane for 4 bands (80, 40, 30
> and 20). I will do a similar install for the 17, 15, 12
> and 10m bands but will have them be 1 to 2 feet down vertically from the
> 1st set of radials. Hopefully, this is clear and not confusing - I do not
> think I am able to post a diagram of what I want to try.
>
> Couple of questions:
>
> Will this work?
>
> What is the minimum spacing horizontally and vertically for the radials as
> proposed?
>
> Any other suggestions?
>
> Thanks,
> Dale
> AF7WH
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