Archive for October 16th, 2015

A Mystery Block of Electronics

Back in the day, this surely represented an achievement in high-density electronics packaging:

Electronics Block - 1

Electronics Block – 1

A view from the other corner suggests the layout wasn’t quite right:

Electronics Block - 2

Electronics Block – 2

It has no identification, the transistors have house numbers, and the PCB looks like a prototype. As nearly as I can tell from the capacitor date codes, it dates back to the mid-1960s.

Two pairs of electrically isolated and thermally bonded transistors suggest an analog Class-AB driver + amplifier or a pair of digital flipflops, but there’s no way to tell.

Judging from the ugly solder and dislodged via rings, somebody had to apply extensive modifications after initial assembly; it trailedĀ half a dozen red wires soldered to vias and components.

One hopes it eventually worked…