I have a set of these on my bench right now - I've found some things on the PCB that are not consistent with the schematic. For instance, the anode of 1D9 connects directly to 1IC6 pin 13 (not to 1R67 (10K) as shown). Also, there is a handwritten note that PCB pins 34 and 35 (part of ratio switch feeding 1IC6a) are reversed. I traced it out - what should go where per the schematic, and this is in fact the case. When I reverse wiring to 34 &35, the zero of the meter changes slightly with each setting of the ratio switch... leading to my question: is this normal? Does anyone have a correct unit? Before I did this to the "working" unit, the zero shifted quite a bit less if at all.
Any ideas or comments?
I agree, regardless of the chips, these units are WAY cool...