Disappointment

Q. Does anyone have a circuit additive for the TUBE theremin that at least equals Clara's Tube theremin? I am a newbie at vacuum tube technology and design, but am good at following instructions. PICTURES of a circuit that I can ADD to make linearity better spaced.
Please reply with ideas and some pics. Thanks. RSM

"PICTURES of a circuit that I can ADD to make linearity better spaced."  - weirdvideos

Analog Theremin linearity comes from two interconnected LC resonances fighting each other, and they have to be properly designed in order to do so.  You might study and experiment with the Moog Etherwave here, the coils in series with the pitch antenna form a resonant LC with the antenna, and there is an LC oscillator on the PCB driving it.  You'll need an oscilloscope and some theory.  When properly tuned the end result can be fairly linear.