The Ferrite bead is from Wurth Electronik. Some of these parts are available from Digikey. This part is very similar
The bead is not super critical.
My risetime has not been peaked. I don't have a capacitor on the collector of the transistor, only the transmission line. It opens up a much bigger question as to why the risetime on an oscilloscope looks the way it is.
If a scope had a single pole at the bandwidth frequency then the waveform would look exponential.
Oscilloscopes have been engineered to have a Gaussian Response.
Here is a SPICE model of a Gaussian Filter
The reponse in the Frequency Domain
The response in the Time Domain
One of the properties of the Gaussian filter is that as you reduce the risetime on the input the risetime on the output reaches a minimum. After this point the risetime on the output becomes fixed.
HP made some Transistion Time limiters based on this property. The model numbers are 15432 through 15435
What is interesting about this, is that the waveform from my pulse generator looks flater on a low bandwidth scope than it does on a higher bandwidth model.
The bottom line is that you should not see overshoot unless the input is overshooting.
Is there a Gaussian Conspiracy ?