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After working with
fiberglass tubing in my homebrew
Hexbeam, I came to appreciate the advantages of using light
weight composites to support wires for HF
antennas.
I was planning to homebrew a
30M / 40M
vertical out of aluminum tubing salvaged from an old beam, but then
I stumbled
across
S9 vertical antennas which are made from
telescoping fiberglass tubing, with a wire running inside.
With a little base loading
the S9V 31 ft. vertical
makes a good resonant 40 Meter antenna. And with a tuner (or a base
capacitor) it makes a fine 30M DX antenna too. Not only that
it comes in a stealthy green color (like my
AB-577 mast). Since the
antenna was very reasonably priced, I decided to give the S9V
antenna a try.
S9 Antennas sells a
radial plate with
stainless hardware, as part of a package deal with the S9V
antenna.
Shipping was very fast, just a few days from Texas to my
Pennsylvania QTH.
I bent a piece
of aluminum and drilled a few holes to mount a SO-239
coax connector on the plate, as
seen below.
S9 Antennas Radial Plate
with SO-239 added by me
Each of the 20 ring connectors has 3 wires soldered in...
for a total of 60 radials
Most of the radial wire came from un-twisted
CAT3 twisted pair cable. Using a reversible variable speed drill, two helpers
(daughters) and a fair amount
of patience, I got my 60 radials, free.
I drove a pipe into the ground and
spread out the 60 radials pinning them down
with cheap radial anchor pins from
Ross-Radio.
Here is the
installation with homebrew 40M base coil and a variation of the
ugly balun
(wound on a large plastic juice container). I optimized the balun for
best
common mode choke
impedance at 30-40M.
You might notice grass seed on the bare ground.
I have since added a separately fed 30M wire element. The wire element goes up to a tree, at about
a 30 degree angle from vertical...and away from the mast. This way,
the antennas don't interact much, and the ground plane is used
for both vertical elements. The DX results of this antenna on
both 30M and 40M have been very gratifying.
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