I just went back into an old post from months ago. See below. I use radio waves.
Cable and pipe tracer.
I needed to build one in an evening to track the water pipe and 110 volt wires going from the house to the well. With no water time was critical. (make it simple)
The receiver: Use an AM portable radio.
The transmitter: 9 volt battery, LM78L05 voltage regulator, 1000pf 500 volt capacitor, two alligator clips, crystal, and 74HC4060 osc/counter. The 500 volt capacitor blocks DC and 60hz AC from coming into the output stage. I chose a crystal frequency with a harmonic in a quite place on the radio dial. The 74HC4060 has many Q-outputs. One of the outputs had an approximately 2khz tone. Using a simple OR circuit I summed the CLK2 and 2khz together. The output was a square wave with a harmonic at 1mhz, turned on/off by a 2khz square wave.
To use:
(ground lead from transmitter) Connect one alligator clip to ground, or your metal tool box, or a 2 foot piece of wire. Almost any thing.
(signal lead with DC blocking capacitor) Connect one alligator clip to the wire or pipe you want to trace.
Wave the radio near the wire/pipe. Twist the radio around. Most AM radios are more sentient in one direction.
I followed a, 5 foot, buried wire 50 feet. At the house I could hold the radio and walk. At 50 feet I had to set the radio on the round to detect the wire.
Cable and pipe tracer.
I needed to build one in an evening to track the water pipe and 110 volt wires going from the house to the well. With no water time was critical. (make it simple)
The receiver: Use an AM portable radio.
The transmitter: 9 volt battery, LM78L05 voltage regulator, 1000pf 500 volt capacitor, two alligator clips, crystal, and 74HC4060 osc/counter. The 500 volt capacitor blocks DC and 60hz AC from coming into the output stage. I chose a crystal frequency with a harmonic in a quite place on the radio dial. The 74HC4060 has many Q-outputs. One of the outputs had an approximately 2khz tone. Using a simple OR circuit I summed the CLK2 and 2khz together. The output was a square wave with a harmonic at 1mhz, turned on/off by a 2khz square wave.
To use:
(ground lead from transmitter) Connect one alligator clip to ground, or your metal tool box, or a 2 foot piece of wire. Almost any thing.
(signal lead with DC blocking capacitor) Connect one alligator clip to the wire or pipe you want to trace.
Wave the radio near the wire/pipe. Twist the radio around. Most AM radios are more sentient in one direction.
I followed a, 5 foot, buried wire 50 feet. At the house I could hold the radio and walk. At 50 feet I had to set the radio on the round to detect the wire.