Hello, i've run across a picture of Sonic Wave theremin that shows the inside
of the box and the top of the PCB. I would like to build it. Looking at the PCB,
i can see two oscillators mixed on a diode. It is very a simple design. What
makes me confused is that the DC is fed straight to collectors. I can't find an
oscillator like this - super simple one tranny design. Also 1M resistors (if i read
them well) don't help me ... i haven't found anything with 1M in it.
Could anyone help me please? If you look carefully at the pictures, you can
see that one of the ceramic caps (the left oscillator) is disconnected. Are
those ceramic caps a part of the oscillator or are they coupling caps to the
mixing stage? The other two ceramic caps at the middle-top are probably an
output cap and a low pass filter. I have no idea what is the single resistor
(top-left) for ..
Otherwise the oscillators look pretty much symmetrical - tranny, adjustable coil,
huge resistor, adjustable cap/antenna, maybe the ceramic caps as well.
If you guys have this thing at home, or if you see further than me please help.
Thank you.