theramin circuit

[kz0e]

Hi Guys,

A friend is into theramin's and has asked for help coming up with a solid state replacement for a theramin circuit that uses a '120' triode. I havnt seen the schematic yet but I understand it's set up with rf into the filament, and supplys cathode current into an amplifier stage, sounds like an rf power to dc current converter to me.

Anyone seen this before or have any tips/info? I wonder if it doesnt have some nice and funky transfer function or special distortion that contributes to that 'theramin sound' that might be tough to reproduce.

I guess those 120 tubes are up to $60 a piece.

Larry

[Rob K2CU]

Check out the following:

http://www.thereminworld.com/schematics.asp

http://www.rogo.com/folkstuff/theremin.html

http://home.att.net/~theremin1/

[N0BST]

How about using an optocoupler instead?  Use a transistor to vary the intensity of the internal LED.  Or he could use a lamp and photoresistor combination.

Scott

[wavebourn]

My humble opinion: this one is the best.

http://www.oldtemecula.com/theremin/ultimate2b/index.htm