A few days ago at work we got some new computers in and decided to call one of them 'Theremin' since all the others were named after instruments and we were running out of ideas. A quick browse later and I found Art Harrison's web site on Theremins. This is built from his '2006 Minimum Theremin' instructions and I found it pretty easy to find all the components at Maplin. It's a simple design, meant more for demonstrations and science fairs than musical use - Art has designs for more sophisticated theremins on his site. I've no doubt reduced its musical quality by deviating from his design, but you can still get a tune out of it. I've left off the tone control - it's an preset on the board rather than a proper control - but you can alter the range quite adequately by adjusting the length of the telescopic antenna.
