2026-05-03
Printed Circuit Boards --- then
Recently I came across a little electronic something, which has one of the oldest printed circuit boards (pcb) I ever attempted. And "printed" is essentially wrong in this case. Allthough photo transfer of a circuit board on transparent film was wide spread, I never got into that. This particular piece was hand drawn on the cleaned copper side of a prototype board, then etched (FeIII-Cl, yuck!) and cleaned. Every hole was drilled manually. I did not even put solder on everything to prevent oxidation, before I added all components and cables.
Clearly I had to fix some mishap. And I remember, that the circuit did not work --- of course! It never does! But then I stared at this for a while to understand exactly, how it was supposed to work. And look! There was a mistake in the schematic! I exchanged two resistors, and then it worked! For the first time in my electronics tinkering life I did not give up and fixed the thing!
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Still, even this old board is a small wonder, because it worked despite all the crude tooling available to me at the time.