Oscilloscope

While playing with an old Hameg HM504 and the Tektronix 465B oscilloscope that I repaired recently, I thought that I should do yet another mandatory tinker project: Using a microcontroller to write text on an oscilloscope screen via the XYZ-mode. And so I designed a small USB powered board around the STM32G441KBT6 which seems to be my go-to microcontroller nowadays. Its fairly capable dual channel 12-bit DAC (up to 5 MSPS) comes in really handy for generating the x- and y-components. Initially I thought about using a discrete 8-bit R2R network to modulate the brightness with the Z input, but after testing the circuit I finally decided keep it simple and just implement blanking with just a single GPIO output. ...

As many people in the community I really enjoy watching W2AEW’s YouTube channel. Almost a decade ago he posted a video showing a cheap and easy to build pulse generator for time domain reflectometry (TDR), consisting of only a simple hex inverter with schmitt-trigger inputs 74AC14 and a few passive components. The schematic looks something like this: Schematic of the schmitt-trigger oscillator plus output driver ...

For engineers analog oscilloscopes are a bit like vinyls and tube amplifiers: Most don’t use them anymore, but if they see one, they think: Nice! And are happy that they don’t have to deal with them on a daily basis ;) However, I bought a Tektronix 465B with a faulty second channel, just to repair it. For this one, I made a quick YouTube video. ❗ Caution High voltages found inside of analog oscilloscope can cause damage, severe injury or death. If you are not authorized or qualified to work on such devices, don’t do it. I don’t take any responsibility for actions you take or the results of these actions. You do everything at your own risk. ...