Micronta 22-121

[staze]

All,

Here's a blast from the past. I picked up a Micronta for dirt cheap on fleabay (like, $10). I wanted a cheap dual rail PSU. Heck, even if I went to build one, the transformer would cost more than $10!

I'm ordering some 10turn pots for the voltage adjustment (since the current single turns are useless), but one thing that I'm curious about is I can't get the tracking aligned. There's a trimpot internally that's 2k, but it's hard against one direction, and the voltages are still about 0.1V off. I'm attaching the schematics... but I'm curious if anyone has any simple ideas. Maybe whacking in a 100R resistor on one side of VR3?

Anybody got one of these? I looked for anyone hacking one into something better, but couldn't find anything. Obviously I could just forget tracking, and manually align both sides with the 10 turns, but that defeats some of the sexiness of a dual power supply. And yes, I know, I should just buy a modern PSU that does this kind of stuff... but where's the fun in that? =D