How can I build a simple pulse generator to demonstrate transmission lines (electronics.stackexchange.com)

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.

That's pretty cool :)

Great article! aside: I've never seen Stack Exchange used as a blogpost medium (which normally this kind of write-up would be) and I like it! It's still formatted as Q&A so people with the same question can find it, and what's more, suggest edits or write alternative solutions (as OP explicitly invites here) on equal footing themselves. A collaborative quest for the answer, but not anonymized like a wiki.

The real gem is the answer at the bottom about doing the same thing with a bit of transmission line you treat as a capacitor.

This is a great post about the basics of what happens in transmission lines.

If you need really fast rise times, there are cheap pulse generators that are a couple orders of magnitude faster: https://leobodnar.com/shop/index.php?main_page=product_info&... At this level everything has to be optimized including physical geometry.

Any recommended resources for learning the first principles required to understand this and all the components involved?