Hi,

I've been building a theremin but had troubles finding components due to the age of the design. Luckily I managed to find a reworked version with new components. The pitch part of the circuit consists of two oscillators, the only thing that is different is the inductors in the resonators which have each been replaced with two inductors (one being variable). My problems is, that the pitch tuning circuit that connects to the fixed pitch oscillator has different value components (C10 and C11) being1 uF capacitors swapped with 0.47 uF capacitors. The other design difference is that C11 is now connected to +12 V rather than ground. I'm not sure why these changes have been made, can somebody shed some light on the matter.

New design



Old design



Thanks

Ross

 

Hello,

There are some more differences in the theremin schematic.
In the upper schematic C11 is connected to +12 Volts.
In the lower schematic C11 is connected to ground.
As they are likely to be decoupling capacitors, the effect will be minimal.

Bertus

 

This might be of interest -

https://www.hackster.io/user462411/theremin-made-with-cypress-psoc-396db3

https://www.element14.com/community...t16-proximity-theremin?displayFullThread=true


Regards, Dana.

 

Hello,

There are some more differences in the theremin schematic.
In the upper schematic C11 is connected to +12 Volts.
In the lower schematic C11 is connected to ground.
As they are likely to be decoupling capacitors, the effect will be minimal.

Bertus

Are these decoupling capacitors used to reduce the amount of noise produced by the transistor?