Circuit Sniffing

index
555 touch sensor
air mike
amplify your toy
box your toy
circuit sniffing
clock tickling
contact mike
electret mike
hack the clock
laying and hacking
laying of hands
light theremin
make a cable
mapping
pickup
piezo driver
resistors
soldering
sudomini
synthesis
tape head

Pick up electrical activity in the air around you...

You will need:

• battery-powered AM radio;
• battery-powered amp/speaker;
• inductive telephone pickup coil or loose electric guitar pick-up;
• hundred feet of wire, an audio plug and 2 long pieces of wood.

Switch radio to AM. Move it around electrical appliances: flourescent lights, electric motors, computers... Fire a camera flash. Also try FM.

You can also use a simple coil of wire and an amplifier to pick up electromagnetic signals. A telephone pick-up consists of yards of copper wire wrapped around an iron slug. This coil acts like a radio antenna for low frequencies.

Take a hundred feet of ordinary insulated wire. Wrap it around a wooden armature. Solder one end of the wire to the tip of a plug that fits into your amp and the other end to the sleeve.