I ran across this thread that starts with, "Here is a simple pulse generator I have made for testing medium BW scopes' rise times. It produces flat top signal with clean and fast rise and fall edges."
He uses a MAX3949 Laser Driver to generate the signal.
He started with 40 to 50 ps and got a little better each iteration. Also, has better connectors if you need them and some other mods.
It's not a toy, but priced well. Somewhere between $60 and $100.
Here's the thread starting when people started receiving their pulsers and making scope measurements. The first few pages were just people placing orders before he started production.
Don't be turned off by the eevblog, some high end developers commenting in this thread.
There is a Google sheet comparing dozens of different scopes and their BWs.
Here's a video from the thread, using the pulser to show bumps from Vias and square corners, I found it very interesting but useless to anything I do.
The pulser use starts here,
That whole video starts here with a lot of high speed talk. Hmm, I guess you will need to move the cursor to the beginning I could get a link that didn't start at 11 minutes.
Here's a review video by The Signal Path, shows a 40ps Rise time on a
13GHz Agilent Scope. It may have been better, I didn't understand some of what he said.Mikek