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Subject: RE: [motm] RE: Paia Theremin

From: "Tkacs, Ken" <ken.tkacs@...>
Date: 2000-03-30

RE: Paia Theremin
The Paia manual says to use a supplied clip lead to essentially hold the 'gain' circuitry open, removing that from the equation. I get the impression that this is ∗supposed∗ to allow the pitch oscillators to make noise, no mater what state they're in. I spent an hour or so twiddling the coils but couldn'tget anything out of it. The LED comes on; that's about it. I didn't have the time, at the time, to complain to Paia about it, and since I was using a custom enclosure, etc., it wasn't like I was following their instructions 'to the letter' and could send it back for repairs or anything. I keep telling myself that some day I'll spend some more time on it, but I really don't know what to try next. Maybe I will try to throw a scope on it.
 
-----Original Message-----
From: John Speth [mailto:johns@...]
Sent: Thursday, 30 March, 2000 12:50 PM
To: 'motm@onelist.com'
Subject: [motm] RE: Paia Theremin

The PAIA theremin, IMO, is not engineered very well so you'll probably need to do battle with the beast.  RF circuits when first powered can be real tricky to align depending on the initial settings of the coils and component tolerances.  Some units can be so misaligned that they'll seem dead.  A scope helps greatly in this situation.  The debug it, try to observe the freq from just one oscillator by adjusting the coils for just that oscillator.  Repeat the operation for the other oscillator.  And finally using the scope make sure the frequencies for both oscillators are as close to possible as you can get.  At this point, assuming there's not bad parts or construction errors, it should make some sound.

John Speth
Molectron Detector, Inc.
http://www.molectron.com
mailto:johns@...

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