If there is a free end accessible you might try feeding some rf into it
and then following along with a receiver to detect the underground
portions. This may or may not require strong attentuation at the
receiver antenna -- using a short loop or something across the input.

If there is one level. chances are you may find others underneath with
a little digging unless there are accessible ends to them whereas tracking
the RF would work just as well.

Just a wild and maybe not so crazy idea of how I'd try for a quick cheap
fix.

Irv VE6BP


"Hul Tytus" wrote in message
...
rec.radio.amateur.antenna
metal dector for barbed wire fences

Anybody here have any suggestions for possible ways to detect fence
wire,
mostly 1, 2 or 3 levels of barbed wire but also some 8 inch square matrix?
Typical mounting would be on a tractor or trailer, so the detector would
need
a sense of direction, ie looking outward not inward. Minimum range would
be
around one foot with 4 feet probably optimum.
Typical retail metal detectors have a short range and need a metal free
environment, leaving the methods they use somewhat doubtful. Evidently,
there
are detectors with seperate heads/coils and 1-5 foot ranges but, once
again,
require a metal free environment.
One possible area would utilize rf antenna's, one transmiting and the
other
recieving a reflection from the wire(s). A parabolic or corner reflector
type
antenna maybe if not for the high frequency - two 12 inch antenna's would
be
about max size and that's in the gigaherts range, which might be a
problem.
Any suggestions along this line will be appreciated.

Hul