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Add: Note the color controls are just up-down switches. This chassis had analog memory modules for the remote adjustments. The module used a low leakage capacitor whose voltage was read by an FET. To change the voltage, it was charged or discharged through a small neon bulb, which had very low leakage in the off state. The bulb had to be an earlier model specified to have no radioisotope content. Later versions of neon bulbs included a small amount of radioactive isotope to pre-ionize the gas and get a consistent firing voltage, but this would have slowly discharged the capacitor. The whole memory module - cap, bulb (or bulbs, can't recall if there were two) and FET was potted with low-leakage epoxy.
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