The VOR is a very valid concept, and I've modeled it in a couple of
different ways to investigate it. I'm even thinking of building an 80m
vertical based upon it so I don't have to string wires around.
But the truth is that ANY properly tuned counterpoise (which is pretty
much what the VOR is) will perform the same function since we're not
talking shielding the RF from the earth here if we're not actually
running wires out away from the antenna. All that is necessary is that
whatever is connected to the shield side of the feedpoint provide a
place for current of the proper phase to go to offset the vertical portion.
That doesn't have to even be a ring ... it could be a spiral, although
coupling effects to itself make that a bit less deterministic.
That's why even a rats nest of random wires like the one I had for the
top loaded 80m vertical on the flat roof of my previous house worked
pretty well for several years . You just need to trim stuff to make it
provide provide the right balancing current and phase ... or include
some adjustable reactance inline (inductive or capacitive as might be
needed) to accomplish that ... or even use a matching network at the
feedpoint to get the right net phase.
Dave AB7E
On 10/27/2025 9:03 PM, Jack Brindle via TowerTalk wrote:
One very pertinent thing that has not been mentioned is N6BT’s development of Vertical Open Ring (VOR) antennas.
In this design the “ground wire” is actually a 1/4 wave ring that wraps around the base of the antenna. The
vertical is up off the ground some distance (less than 1/4 wave, perhaps 1/8 wave). The antenna is described in the
latest (4th) edition of Tom’s book “Array of Light”. He has spoken of it in quite a few
presentations that are now available on Youtube, including an NCCC meeting earlier this year. Definitely worth a view.
It is also interesting that the November issue of QST shows an antenna of this design, by
G4UNA. Either the author re-invented Tom’s work, or failed to give him credit, but
this article also demonstrates the VOR concept. Essentially the radial consists of a 1/4 wave
piece of wire that extends out from the base at an angle, then forms a partial square around
the antenna. The wire is terminated before it touches itself, thus the square is not
completed. In Tom’s experiments he showed that the wire might make up only three sides
of the square and perform just as well as if it extends on the fourth side.
By the way, his book is also a gold mine for ideas about raised radial
verticals. They perform incredibly well at the beach - he still holds several
QRP records from the Caribbean for QRP contests using these antennas.
Contemporary reports show that the gull-wing style of radials perform very well.
This topic is very well discussed in ON4UN’s “Low Band DXing” and slightly
lesser so in the latest ARRL Antenna Book.
Sounds like some experimentation may be in store to see what works best for the
OP.
73,
Jack, W6FB
On Oct 24, 2025, at 6:03 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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