Saturday, February 11, 2012

S9V 40M Vertical at WY3A Fiberglass / Wire 40M Vertical

S9V 40M Vertical at WY3A Fiberglass / Wire 40M Vertical

The S9V almost disappears in the back corner of the yard.  Can you see it?

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.

1 comment:

Antoni Karol dianovsky said...

HELLOW very didatic tks LIKE to ask you question abt size radial ? do you uses 1/4 wave 10m on 40m ?