Pitch problem

I've built a Etherwave Theremin, from the kit set, and everything was fine, until i left it untouched for about a year. I wanted to play it again, but now suddenly my pitch is messed up. The the silent zone is removed like 10-12 cm from my antenna at the best configuration, so i only have a very small area to play in. I can however get the silent zone at a normal distance from the antenna, but then the low and high notes are reversed, so that's not really an option.

Can someone help me out?

Your instrument needs retuning.
You will have to adjust at least L6 and perhaps L5 as described here in this service manual (http://www.moogmusic.com/manuals/HotRodEtherwav.pdf) on page 7

If this seems too complicated for you, there is an alternative solution: An experienced theremin technician who may fix this for you resides in Alsace/North-Eastern France ;-)
He speaks also French and German and does understand Italian, Russian and Dutch if spoken slowly or written.

There is the option to send your Etherwave in, get it tuned and sent back with the risk that the transport shocks will worsen the results. Or you travel and spend a day there with your instrument in order to get it not only fine-tuned but rather calibrated following your individual needs.

If you are interested, write an email to theremin(at)tfrenkel(dot)com

I would add, that (it may be in the manual) you will want to make certain to place the lid over the theremin to check your tuning each time you make an adjustment. Otherwise, when you button the theremin up, it will still be out of tune.

You don't have to unplug or power off the theremin to do this. Just flip the lid upside down, and rest it on the theremin while it's on to test. Then, if need be, make your next adjustment, and repeat until you have it set to rights.

I have a theremin lid with holes drilled in it where the tuners are located so I can retune quickly.

Good luck with tuning.

Ah, i followed the steps in the manual, and it worked. Thanks a lot!

And thanks for telling me about the lid too, it really helped.