16 points | by alphabetter 6 days ago
3 comments
Decades ago we used a much simpler method. A few 50 or 75 ohm non-inductive resistors and a tunnel diode.
Feed any (slow) pulse generator into the diode and make it switch. Tunnel diodes can have sub-nanosecond switching times.
We also used this technique to check/measure the rise times of our oscilloscopes.
sometimes, I realize how much is taken for granted these days that when I stop to think about is one of those "whoa" (in a Neo voice) moment. being able to time something in the picosecond range just gives me a wry smile.
Nice write up and sneaky introduction to time-domain reflectrometry but I'd like to point out the classic answer to this question is the famous Jim Williams pulse generator: https://github.com/podonoghue/Jim_Williams_Pulse_Generator?t...
Decades ago we used a much simpler method. A few 50 or 75 ohm non-inductive resistors and a tunnel diode.
Feed any (slow) pulse generator into the diode and make it switch. Tunnel diodes can have sub-nanosecond switching times.
We also used this technique to check/measure the rise times of our oscilloscopes.
sometimes, I realize how much is taken for granted these days that when I stop to think about is one of those "whoa" (in a Neo voice) moment. being able to time something in the picosecond range just gives me a wry smile.
Nice write up and sneaky introduction to time-domain reflectrometry but I'd like to point out the classic answer to this question is the famous Jim Williams pulse generator: https://github.com/podonoghue/Jim_Williams_Pulse_Generator?t...