New member here, pleased to have found this terrific resource.
I am interested in building a Theremin using vintage tubes. I have just enough 27's, a 24A, and a 53 to get close to the circuit shown in the schematic of Clara Rockmore's instrument.
I am currently prototyping using less scarce (and 6.3v) tubes: 76's for the oscillator, 36A for the mixer.
A problem that I'm having at the moment: the pitch oscillators lock to each other. This happens when I connect the two oscillators to the mixer - if I leave them disconnected, I can move the frequency of the variable oscillator; but once I connect to the grids of the mixer tube, bing! the oscillators lock.
I would like to look at Mark's measurement data (but it's no longer accessible) and Pierre's schematic (but I see a blank Word doc).
Appreciate any pointers from people who have done something like this.
Thank you very much,
--ian
I am interested in building a Theremin using vintage tubes. I have just enough 27's, a 24A, and a 53 to get close to the circuit shown in the schematic of Clara Rockmore's instrument.
I am currently prototyping using less scarce (and 6.3v) tubes: 76's for the oscillator, 36A for the mixer.
A problem that I'm having at the moment: the pitch oscillators lock to each other. This happens when I connect the two oscillators to the mixer - if I leave them disconnected, I can move the frequency of the variable oscillator; but once I connect to the grids of the mixer tube, bing! the oscillators lock.
I would like to look at Mark's measurement data (but it's no longer accessible) and Pierre's schematic (but I see a blank Word doc).
Appreciate any pointers from people who have done something like this.
Thank you very much,
--ian