Noisy pots have been around forever! One test we used on audio equipment years ago was to use the pot as a voltage divider, but, place a small audio transformer (Lo-Z side) in series with pot. Connect the other transformer winding (Hi Z)to an audio amp, or maybe even Hi-Z headphones. Now you...
A few years ago we neeeded a temporary source of 50Hz/1Kw
and used a 5kw gas generator, with the speed reduced. We changed a governor spring and tweeked it for 60Hz. It was quite stable, the voltage was close but since the load was light enough there was no serious sag...Just a thought
