We used to build them with 1N34A diode, capacitor across the headphones,
and a coil wound on a toilet paper tube, with taps on the coil
that you'd clip an allegator clip to, for tuning.

Assemble atop wooden board.

There were some with an actual cat whisker instead of the diode,
but we went the modern way mostly.

The project is mostly winding the coil, many turns of enameled wire,
and scraping bits of it clear of enamel for the allegator clip
landing spots.

Another tuning method was a slider over the coil but it never
seemed like that would be very easy to get to work reliably.

Antenna and ground across the live portion of the coil.
--
Ron Hardin


On the internet, nobody knows you're a jerk.