JohnDW wrote in news:MPG.1f9195c698c090c9989759
@news.aaisp.net.uk:

Yes, you can inject a tone and trace the wire using a
detector. You don't need a high frequency, though, since it
will be coupled into parallel cables and so give false
positives. "Cable tracers" normally use audio tones. Search
Google for examples.



I do PA work in churches, also. An old trick is to put a light bulb,
which you already have on the other end of the wires in the boat, across
the line on the other end. Pump some audio through the wires from about
any amp to make the bulb glow. This produces audio current in the line,
without producing loud noises, too. Radio Shack used to sell a
"telephone amplifier" that was a sensitive little audio amp that ran off
a 9V battery with a pickup coil you stuck to the back of the phone's
handset with its suction cup. It picked up the audio magnetic leakage
from the earphone in the handset and fed it to the little speaker-
amp.....

All you do to trace the wires is run the little coil up to each wire you
think is the circuit the audio is hooked to. It's real easy to hear the
audio in the speaker when you get close to the right wire....you hear it.

I'm still using it, 20 years later. Everytime RS dumps these at some
yard sale they occasionally have, I buy them out for $1-3 each....coil
and all.

No, you can't have mine....(c;

Check around electronics stores for "telephone amplifiers".....or the
net.



--
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You can tell because none of them ever called Earth.