Wimshurst machine with 2 sectors as LC circuit

This is a replication of something done by one of the members of the testatika Yahoogroup. It modifies two sectors of a Wimshurst machine to act as the capacitor(s) of an LC resonant circuit with a coil wrapped around the pulley shaft. This Wimshurst machine was used.

First rectangular pieces of acrylic were taped onto sectors on opposite sides of one of the disks. This is done on the outer face, so they are taped directly onto the foil sectors. These are the capacitor's insulators. Sitting on the disk you can see the two pieces of aluminium tape that will be the other capacitor plates.
Then 48 turns of #26 enameled wire was wrapped around the pulley with one end extending out onto each acrylic insulator. The wire ends were sanded bare.
Each end was looped and then pieces of aluminium tape were taped firmly on top to act as the second plates of the capacitors.
A piece of black electrical tape was then added over each capacitor to insulate them.
The test setup consisted of the Wimshurst machine, a radio capable of AM, FM, SW1 and SW2, and an oscilloscope.
A closeup of the disk in place.

Test results

Whenever the disk was rotated, static was heard on AM, SW1 and SW2 but not on FM. At the highest end of SW2 the static came through almost as clicks. The output on the oscilloscope in the picture below shows that the signal was very noisey, however, it seemed to be interacting with the oscilloscope's probe as some sort of amplifier as the central peak below would grow more as long as the disks were turned but no matter what frequency I set the oscilloscope to, I could not get more than one peak, just the central one and the noise around it. Note that I did not set up any antenna for the scope; I just left the probe sitting on the table.

Click on the following for the video (800K). Turn up the volume to hear the hiss while the disk is turning.

You may need QuickTime to view it. If you don't have QuickTime you can download it here.

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