How can I build a simple pulse generator to demonstrate transmission lines

19 points by alphabetter5 days ago

3 comments

hilbert422 hours ago
Decades ago we used a much simpler method. A few 50 or 75 ohm non-inductive resistors and a tunnel diode.<p>Feed any (slow) pulse generator into the diode and make it switch. Tunnel diodes can have sub-nanosecond switching times.<p>We also used this technique to check/measure the rise times of our oscilloscopes.
- dylan60459 minutes ago
  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.
KK7NIL2 hours ago
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: <a href="https://github.com/podonoghue/Jim_Williams_Pulse_Generator?tab=readme-ov-file" rel="nofollow">https://github.com/podonoghue/Jim_Williams_Pulse_Generator?t...</a>
SilentM6824 minutes ago
That's pretty cool :)