Troubleshooting- Pitch help on etherwave!

Posted: 3/9/2008 7:51:01 PM
gertietheduck

From: United Kingdom

Joined: 12/28/2007

I am having a similar problem...
My theremin has been absolutely fine, since I bought it, and I was finally (finally!) starting to make progress, until a few days ago it began behaving in a very strange manner. Usually, when switched on, the field will start out very small and expand as the theremin warms up, and then, once it's warmed up for 15 minutes or so, I would adjust it to my requirements. Not so, now!
Now, when I switch it on, the field is immediately enormous and once the theremin has warmed up, it becomes so huge that I can at most play an octave, and the jumps between two notes are so great that I can only play melodies if I set my hand inches from the antenna.
I was going to post a topic about this, but then I found this old thread...
I am going to check all the things you have already suggested be checked(cannot do so accurately at the moment as sleeping flatmate would kill me), but I don't think anything has changed in the environment I play in, and nothing has happened to the theremin/cables to cause this. Can the weather have any adverse influence (sorry if that's a stupid question, but I am not techy and am...erm..stupid)?
Please tell me I won't have to open up my theremin, as no good can come from *me* doing that... and my theremin was second hand(and thus not under warranty)...
Posted: 3/10/2008 5:06:06 AM
Thierry

From: Colmar, France

Joined: 12/31/2007

Finally those who have problems with a too small pitch field on an Etherwave Standard (that means too small antenna capacity or completely drifted oscillators) may check three or four things:

a) Grounding: Make sure that you have put your power supply in a grounded wall plug and that its other connector is well plugged into your Etherwave.

b) Antenna connection: Open the Etherwave after having unplugged it and check (best with a simple multimeter) if the resistance from top of the pitch antenna until the point where the pitch antenna wire is soldered on the printed board is below 10 Ohms. If not, check the screwing of the wire to the antenna mount. (Please excuse my bad english, I'm french and german native speaker. Hope you understand what I want to explain)

c) Reconnect the power supply to the open! Etherwave and switch it on. There is no risk, since it's operating on low voltage. The pitch field should have become still smaller, since the capacity of the screws is missing. Bend the famous wire downwise towards the aluminium foil (without deconnecting it!). This should already increase the pitch field.

d) Adjust coils L5 and L6 as described in http://www.moogmusic.com/manuals/HotRodEtherwav.pdf
What they do not write is that you should add about 500 Hz to the indicated values when the cover is open.
So you will have to adjust, close the cover, re-open the cover, re-adjust, and so on.

If all that does not help, you may find someone here in the forum to whom you may send it in for fixing it (me included). The only risk is that you might although have to re-adjust it when it comes back to you since the environment is surely different.

Best example: When I got my Etherwave, it was sent to one of my working places. I tried it out there in a modern building with correctly grounded german wall plugs and it worked fine, out of the fact that even with the pitch knob turned fully clockwise, my hand was still too small to make a whole octave (missing 1/2 inch).
In the evening I took it home to France, where I live in a medieval half-timbered house without grounded wall plugs and there things were still worse. I had to re-adjust pitch and volume circuit in order to get it playable there...
Posted: 4/16/2009 3:37:31 AM
did concombre

From: Tououse - France

Joined: 9/23/2007

Hello, I have bougth an etherwave kit. I have finished mounting it and now i am trying to tune the pitch.
I have some kind of problem with that; I can have the ranges I want by tuning the L5 and L6 coils but there are two major problems remaining:

- when I am about one meter from the theremin the pitch begin to ascend.
- the pitch knob in front has too much effect on the distance between me and the theremin, in other words, if I turn it more than 30°CCM the pitch range is set on 1cm and if it's CCW , the pitch range seems to be kilometers.

Can anyone help me?
Thank

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