I’ve almost forgotten to introduce myself –
I’m just another of those mad trained electronics engineers (based in Germany) which have been infected with the virus many years ago. It’s the Theremin instrument build- and improvement virus, of course. To keep things short, I recently (summer of 2020) decided to publish my observations and findings of my years of Theremin electronics research at my home page (aetherwellen-musik.de). In fact, I forced myself to document the most important issues to not forget them over the years. Many things, even documented rudimentary in note books, had been already vanished from my mind. Every development work has to be accompanied by sufficient documentation, but this task is always the most unloved part. Just a fraction was compiled to be published until now. Especially measurement documents are not presentable and important measurements have to be therefore repeated. This is a lot of work and will take a long time because all is just a hobby and not my daily job. Probably some findings are of importance – time will tell. Where ever possible I try to substantiate things by measurements and using literature. As my old training supervisor always said, measuring means knowing and no one can know everything – but it must be known where to find the information. I collected and repaired vintage radio- and TV-sets, tape recorders, measurement equipment and so on since I was a little boy. The collection of devices and literature is always growing. By the way – as NEUTRODON a vintage 1920s trimmer capacitor was denoted. It was used to adjust the amount of RF compensation to ensure that e.g. the RF amplifiers, applying triode tubes (the only type of electron-tube available in the early days of radio) don’t oscillate. Tendency of oscillation was caused by the high internal capacitances of those early tubes (‘Miller Effect’).
I hope we all can contribute to further improve the instruments and spread the Theremin virus – especially to inspire younger people!
Alex
