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

Posted: Tue Jan 17, 2012 12:23 pm
by PAiA-Scott
Pertinent to Theremax pre-2011.

Theremax updates pdf
9505uds1.pdf
(48.4 KiB) Downloaded 2723 times
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