Hi all, this is my first post here, but I've been reading the forums for some time. I've recently succesfully built an EPE theremin using the information posted here.
Now I'm triying to build another theremin, this time an EW theremin. I've only built the variable and fixed pitch oscillators to make sure it worked right before going on. The main differences with the original is that I dont use the toko coils, instead I've rewound a couple variable inductors from an old radio. Also I couldn't get the antenna coils, so I wound a 40mH one using an old ferrite core. The problem is that with this configuration I get barely 15-20cm range, so I guess I'm not hitting the resonance point.
After this I tried to find the resonance point using a mesurement procedure similar to the one used when tuning tesla coils (more info here http://www.hvtesla.com/tuning.html) and started removing turns of the coil until reaching resonance around 285 kHz. The odd thing is that at this point the coil measures about 12mH, and the antena (12mm OD and 45cm lenght) is very similar in size to the one used in the instructions. Using this configuration the range is increased a bit but the notes are still very compressed near the antenna.
Also the oscilators behave strangely, fist while I'm closing my hand to the antenna the pitch increases, but close to the antenna the pitch goes down to zero and increases again. I dont know what else to do next. Dou you have any ideas? Thanks in advance.