Tuesday, October 7, 2008

Installation 5BTV ground mounted with radials

About a year ago I decided to install my 5BTV in a ground mounted with radials configuration. I have used this antenna elevated with radials for Field Day, but wanted an easy to maintain "clean" installation without the space requirement for the spiderweb of radials when elevated.

I also did not want to spend any money on the installation, using only materials on hand. Wire for radials came primarily from non-metallic sheathed conduit scraps.

The largest open space in the yard with 24' then a fence on one side and 24' then a building on the other side was selected and the 4' support pipe (1.5" galvanized) pounded into the ground. Then PVC pipe was buried and RG8M coax feedline installed.



Conduit and RG8 would be better, but that was not on hand and would have cost money. Besides, I don't use an amplifier. A RF choke was wound around a plastic coffee container.

Then, I made a radial ring out of copper flex tubing and soldered short wires to it so I would not have to solder to the ring in the field.


Radial installation began. I decided on 40 24' radials based on the wire I was able to scrounge. Most of the radials are 12ga solid wire, some insulated, some bare. This homebrew device was used to cut grooves in the soil for the wires:


It was winter at the time so the ground was soft. I buried the radials about 1" down and soldered them to the radial ring. Hard part completed! Next the antenna was mounted and guy wires installed.


Tuning was next, which was straightforward except for having to adjust the 20M trap (the clamp the instructions say to DO NOT LOOSEN) as the tubing between the 15M and 20M traps could be not be shortened enough.



I also polished up the antenna and sprayed it with clear coat for preservation.

About three months later, I got ahold of some more wire and added another 20 radials. This time, I did not cut grooves but instead tacked the radials down with bits of wire expecting them to disappear in the weeds eventually.

Finally, for field day I added 64 temporary radials made out of telephone wire, bringing up the count to 124 radials, all around 24' long give or take a couple feet. After FD, the telephone wire radials were removed.

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