[sdiy] More Theremin - WHY??

[harrybissell]

Howdy all...

I'm playing with the U. Glasgow 'digital theremin'.

I added an RF choke at the suggestion of Grant Richter... it helps quite

a bit. Put the thing in a metal box... that makes it a lot more stable.

For a detector, I'm using a 4013 a'la "thereminvision.com"   The range
of
this thing is in the very high audio / ultrasonic. I plan to get a CV
from it
(eventually).

Listening to the audio output, there is MASSIVE noise at very low
frequencies...
its possible that it is getting some FM interference. As I move my hand
closer
the noise (jitter) decreases.   But WHY ???

Here's a good idea (from the Etherwave)... make the oscillator without
the antenna
the variable one... this way you can tweak the pot without screwing up
the variable
osc.

In a finished product, I think you would need a remote variable
resistance... tough
trick at 20pF   :^P

Trying to make a multi-axis theremin controller by using multiplexed
detectors... might
be pretty hard.   ThereminVision uses the LMC555 which might be more
stable than the
CD4093 I'm using... but 4093 is in stock :^P

H^) harry