Tinkering with junk to develop an interest in real electrical engineering: Totally resonates. Personal recollection from 1983-84 or so follows. We had a brok

Tinkering with junk to develop an interest in real electrical engineering: Totally resonates. Personal recollection from 1983-84 or so follows. We had a broken black-and-white TV that was mined out for parts (tubes, resistors, capacitors etc) but the front shell with the CRT, high voltage anode connector and deflection coils remained. How do we make this light up again with teenager-accessible loose parts? What can generate the necessary voltage? Oh, how about this car ignition coil. How to tickle the coil into generating this voltage, i.e. pulse its primary input? How about this "vibrator" from an ancient tube car radio (a mechanical chopper for turning DC into AC). But how do we rectify multiple kilovolts? No suitable stack-of-diodes rectifier stick on hand. Oh well, resort to the original HV rectifier tube from the TV. But need to power its (directly heated cathode) filament. Cop-out: Do it with a battery or two. Voila, bright spot on the CRT. Can we make it move? Well sure, just apply a suitable voltage (trial and error!) 60Hz AC waveform to the horizontal deflection coil. Voila, a line. What about the Y axis? Well, we can amplify a microphone with a stereo amplifier and drive the vertical deflection coil with the speaker output. Amplitude? Trial and error (volume control). This was getting pretty cool! Except that it was like seeing the waveform wrapped around a cylinder, seen from the side, because of the full sinusoid horizontal pattern. Which looked really neat, but... I can crank up the horizontal deflection by increasing the voltage (I did have a VARIC based adjustable power supply - homemade of course) until only the linear-ish part of the sinewave remained onscreen. From there it was a straightforward matter of an RC phase shift to drive one of the control grids (found by trial and error by applying small DC voltages to various pins until the beam was blanked) to blank out the right-to-left direction. And we had a sort of homemade oscilloscope. This was cool in so many ways but only because the technological underpinnings were still relevant at the time. Nowadays it would be as ancient as dabbling with atmospheric steam engines. Which I'm sure someone, somewhere is still doing. As an extreme niche hobby without a clear track into a profitable career.