basic experiments

JPascal, 
Can you share a volume control scheme? I am interested in your technical implementation of this part of theremin. You may not share, this is your decision and I will understand it.

Hi MIE,
the circuit on the breadboard i have built for the "roboter" video is still a trial stage. But I can draw the schematic and share it here. Give me some days.
JPascal

Hello JPascal and MIE,

The volume control does work excellent from what I observe so count me in, with strong interest, wanting to view your clever design.

I have not done any soldering in the past few years but picked up the iron again this week, almost an addiction, I keep telling myself don’t breathe the smoke. When I was a child solder rosin smelled good... like pine sap.  I am trying to get some of my theremin claims working for a date in Saint Petersburg, Russia very soon. Her classical voice can be elusive but I am teasing her just enough, it will be our last dance. Will be setting up to do a thermal drift test overnight.

JPascal it will be nice to see some old school electronics that I just might understand and it works. 

Christopher

JPascal,
Thank you very much. Looking forward to your drawings. I liked the rather sensitive response of the volume antenna.

MIE

Here is the principle circuit, values will be added later. For the genuine narrow bandwidth high resonance level filter I have applied a patent.

http://www.thereminworld.com/files/photos/16058/theremin_volume_control_jp.jpg

JPascal,

This is really good stuff. I have not worked with them but I think those are NMOS fets? If the parts are readily available I would like to build your circuit and in the process make a PDF with your name on it so it will be etched into the board and others can enjoy your work.

Thank you for your theremin research.

Right now I exploring the Pitch side circuit of my own design. She gave me hell yesterday and today nothing but affection. There is a specific waveform I am after and only then I know she respects my efforts, or is it him?

Christopher

Hello, JPascal!
I tried to pick up the values of the elements on your circuit. Can you tell if something is wrong? Also, I had a number of questions:
1)L21 and L22 is one coil with a tap in the middle or two different coils?
2)Is it permissible to use 2N5484 and 1N4148 in this inclusion?

MIE

D11 is wrong, it must be varactor

Wow, MIE, you are hired! Answer comes soon. Can you post this as LT Spice file? Instead of the varactor diode a variable capacitor could be used.

JPascal,
Thank you. I have some questions:
First, has anything changed in the pitch scheme?
Secondly, what program did you use for spectral analysis?

Here is the LTSpice file:
http://www.mediafire.com/file/yc3kz1i7uo6j3xz/JFET%2528Volume_Stage%2529.asc/file

MIEcomes, Christopher,
now comes my drawings with the values. To the questions: Both coils in the antenna circuit are solid r.f. choke types. The self resonance doesnt play any role because oscillator is tuned at the serial resonance L1 + L2 with antenna capacitance. For spectral analysis of the a.f. signal I use program spectran. The sweep generator I used here with an oscilloscope is a radio service one  RPS 3301 Nordmende. Thank you for posting the Spice file, I will try to import it for testing. Transistors are jFETs, but this type is out of production. They have a 4..5 mA drain current at Vgate=0.