12" down on 160 meters is identical with being on top for amateur purposes for
most midwest soils. I did buried dipole signal loss measurements years back. I
do not remember the exact numbers but for 80 meters one foot down was a small
fraction of one dB compared to laying on top the soil (Michigan soil) And for
160 it would be an unmeasureable difference with amateur instrumentation
(usually just an S-meter) The trenches were cut with my backhoe. By the time we
got to 160 I had run out of time, energy, and the soil started freezing so
never finished that experimental series.
.
I had a Po' Boy lab setup using a Fluke 8840A to measure rectified received
voltage as a voltage drop across a 1% precision load resistor and an
oscilloscope on a reference antenna to ensure the transmitter was adjusted to
the same received signal strength above ground at the burial site for each run,
2 meter handhelds for the crew, etc. It was fun because we were working at
nearly a mile separation to get out of the near field.. I miss those days.
_________________
Topband Reflector Archives - http://www.contesting.com/_topband
|