Tightly wind about 100 turns of magnet wire around a cylindrical object, making sure to avoid large gaps with each rotation of wire. The cylinder is only a temporary structure to facilitate making the coil itself.
A piece of tube is ideal. Leave around 6" of wire uncoiled on each side which you will later solder to the ends of your auxiliary cable, such as a 1/8" mini plug cable with tinned ends (alternatively, use soldering tin).

If you wish to skip the soldering step entirely, use a 3.5mm mono audio plug to alligator clips and fasten the jaws to each end of the coil (then simply plug straight into an amplifier). Alternatively, a telephone pickup coil can also be used (telephone pickup coils use the same induction coil mechanics as this device and can be used for the identical purpose of detecting electromagnetic interference's).

Using a pair of scissors, carefully scrape away 1/2" of the non-conductive varnish coating the magnet wire from + & - ends. Leaving 6" of uncoiled wire on either side of your inductor ensures extra length to work with in case the wiring is damaged in the process.

Slide the cylinder out from the coil and "squash" the coil closer together with your thumb and index finger. With electrical tape bind the tightly wound coil to maintain its shape.

Then, solder the ends of your auxiliary cable to the exposed ends of magnet wire, heating the tinned ends or incorporating soldering tin from its spool will bind coil to cable (which side is + and - is arbitrary). You may also want to insulate your solder joints with heat-shrink tubing, if so apply to cable before you begin soldering.

Components for making the device
Magnet wire
Electrical tape
Soldering tin
Soldering iron
Audio cable

The audio file to the right is a recording of detected interference from street lamps. Download and listen. Within close proximity of an electrical object, direct the device towards it and listen.

If you want your recordings to appear on this webpage, send to emflux580@gmail.com

Notable projects on electromagnetic investigation in the arts

Joyce Hinterding “Aeriology” (1995)
Christina Kubisch “Electrical Walks” (2004)
Zita Joyce “Ethermapping” (2006)
Adam Hyde & Honer Harger “Radioqualia” (1998)