Construction of A Noise "Sniffer"

A noise sniffer can be built from a personal AM/FM stereo cassette player.

EQUIPMENT

^ Personal AM/FM stereo cassette tape player with headphones
^ Four feet of 75 ohm antenna coax
^ One-half inch heat shrink tube the same diameter as the coax
^ A drill and bit the same diameter as the coax
^ Book of matches or hair dryer
^ Soldering iron and solder

INSTRUCTION FOR THE PERSONAL TYPE RADIO

1. Strip 1/4" off both ends of the coax.
2. Place the heat shrink over one end of the bare wire. Fasten the heat shrink to the wire by heating it (a match or a hair dryer).
3. Disassemble the Radio and locate the antenna.
4. Disconnect the antenna and fasten the bare end of the coax to the antenna mount. A soldering iron may be needed.
5. Feed the coax to the exterior of the Radio. Drill a feed hole if necessary.
6. Reassembly the Radio.
To use the radio sniffer, turn the Radio on AM and select an appropriate station.

INSTRUCTION FOR THE PERSONAL TYPE CASSETTE

1. Strip 1/4" off each end of coax.
2. Disassemble the cassette deck and locate the tape head.
3. Remove the head and mount one end of the coax to this point. A soldering iron may be needed.
4. Feed the coax to the exterior of the cassette deck. Drill a feed hole if it is needed.
5. Reassemble the cassette deck.
6. Feed the heat shrink tube through the other end of the coax. DO NOT FASTEN THE HEAT SHRINK.
7. Fasten the head to the open end of the coax. Use a soldering iron.
8. Cover the exposed wires between the head and the wire by positioning the heat shrink tube and heating it.
To use the cassette sniffer, push "play." It will work on the same idea as a metal detector.