Let's assume for a moment that there has been a major disaster, and a trip to the store is not an option. And that your tools/equipment and backup tools/equipment are not available. Could you build a toner and probe out of coconuts and vines, ala Gilligan's Island? No. A ball point pen and some ketchup packets, ala MacGyver? No. Two junked school buses and a snowmobile, ala "The A-Team?" No.
But, you could try this: Use any audio source for the tone, as Merritt said. Then, if you have a guitar pickup and an audio amplifier, this
could be used as an inductive probe.
Would it work? Maybe, but the first issue that comes to mind is that even a small guitar pickup is huge compared to a probe, and would be almost worthless in a tight situation.
Here are some other things that might work as an inductive probe [when connected to an audio amplifier with a high input impedance]:
- The hearing aid coil from the receiver element of a late-model 2500 phone
- The coil assembly from an old magnetic microphone
- a magnetic pickup form a turntable [record player]
- other items of a similar type [hit the junkbox and dig]
Again, emphasis is placed on "might work." Try it and see...
Jim
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Speaking from a secure undisclosed location.
