Underground Antenna Experiments on 160 meters.




Some years back I buried a 30 metre (60-feet) auminium wire one spade
depth in my back garden. Wire was 1.5 mm in diameter. Soil
resistivity about 100 ohm-metres. To scientists that's 10
milli-Siemens. The near end of the wire came up in the shack. That's
under my kitchen sink. It's still there. Open-circuit at the far end.

As a counterpoise, something essential to tune it against, I erected a
wire in the form of an inverted-L. This was about 30 feet high and
overall length about 140 feet. I chose this length because it fitted
nicely into my back garden. The front garden is too short even for an
underground antenna.

On the 160m band I fed into it about 30 watts from a home-brew
transceiver so I can't provide for the record a manufacturer's type
and serial number. However I still have the transceiver which can be
inspected.

Despite a high local noise level of S-6 I was able to communicate up
to 60 miles with mobile stations in broad daylight on SSB. After
sunset I could easily communicate with most of Europe on CW.

I think a record of these buried antenna experiments should be kept
for posterity, alongside the famous biblical work of B,L & E.

By the way, as you see, I did remember to measure soil resistivity. It
was the first thing I did. What buried wire do you think I used to
measure it?
----
Reg, G4FGQ


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