When I was a kid, I developed a fascination with old TV sets. People would give them to me and I'd take them apart and attempt to learn electronics from their interiors. Many were vacuum tube televisions from the 60s and 70s. I would carefully use tracing paper to draw all the printed circuit board traces, and mark locations where capacitors, resistors, valves, and transformers were soldered to the board. All of this allowed me to reverse-engineer the circuitry.
I got fascinated by the high voltage line-output stage drivers which were quite complicated and the source of the 15.625 kHz whistling noise that mostly only kids can hear.
I learned progressively to fix TVs for people this way, plus I found one book on TV repair at the local library. It was not easy without the Internet, but I also enjoyed getting the unboxed internals of the TVs working on my bedroom table, and demonstrating how the 25 kV anode voltage could be made to generate huge sparks to other objects. My room soon began to crackle a bit with lingering static electricity.
← Back to index