Theremax over the years -- updates to the circuit and tuning

Technical notes, diagrams and schematics for the Theremax series of PAiA products.
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PAiA-Scott
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Joined: Sun Nov 09, 2008 2:49 pm

Theremax over the years -- updates to the circuit and tuning

Post by PAiA-Scott »

Pertinent to Theremax pre-2011.

Theremax updates pdf
9505uds1.pdf
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Also, wire lengths are specified in the manual so they can be arranged/routed away from sensitive areas (the four oscillator circuits and the antennae cable ends) as shown in these images. Wires work lots better than skin and bones proximity to the antennae in terms of loading/attenuating the signals in the four RF oscillator circuits. Wires laying against or too near nodes in these circuits can put them out of tuning range or reduce the amplitude enough the f-v circuits (most importantly the one making the Volume CV) and audio output signal are compromised. Our wooden lectern case mounts the antennae a sufficient distance from metal (the case bottom, the front panel) that there isn't trouble from loading.

Wiring images:

Case:
http://paia.com/manuals/docs/PTph/DSC04661.JPG

Kit/FrontPanel_Antennae assembly:
http://www.paia.com/manuals/docs/PTphot ... Repair.JPG
Scott Lee
scott@paia.com
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