Andrey Smirnov :: workshops

Theremin coil construction

There are many ways to build a good coil for the classical theremin or theremin sensor. One possible way to make a coil can be found here: http://www.oldtemecula.com/theremin/ultimate2b/newcoil.htm

Good coil construction was suggesed by the most experienced Russian classical theremin builder Lev Koroliov. It was published in his article on theremin construction in Russian magazine Radio, 2005, #8,9 (in Russian).

The coil framework is a plastic spool with three separate sections.
W1 contains 300 turnes of 0.06 mm wire in the section A.
W2 contains 3900 turnes and devided on three parts 1300 turnes each.
The first part (1300 turnes) is located in the section A above W1.
The second part is in section B and the third one - in section C.
It is possible to insert a standard plastic frame for radio coil with ferrit core-screw (6 mm diameter) inside our frame and use it for fine tuning of the coil inductance. This coil will work on frequency about 100-150 khz.

The same kind of coils can be used in analog sensors #1 and #2 (L1) as well as sensor #3 (L2).

It is possible to try another amount of turnes to change coil inductance and respective frequency of oscilation. Main rool - to keep the ratio between windings W1 and W2 approximetely 1/10.

It is also possible to experiment with ready made coils, adding extra winding, following the same rool regarding ratio between the number of turnes in new winding and original one. For instance some 10 mH coils with extra windings containing about 100 turnes work perfect in theremins with basic frequencies about 350 khz. In this case original winding is used as W2 and extra winding as W1. But result is totaly depending on material of the coil's frame, it's construction, Q factor and many other features, often completely unexpected.

Learn More:

Theremin Sensors

Theremin Kitchen Workshop

Dealing with Theremin Sensors: pinouts and connections

Multichannel interfaces

Theremin Sensors Circuitry

Tests and troubleshooting

Classical Theremins

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