So I finally added an isolated trigger output to that pulse generator. It is just a gdt from a no brand computer supply driven from another gate so it does not disturb that much the main output. The 100ohm on the secondary it’s there so I don’t forget which are the right leads and that capacitor in parallel with the 1k on the primary is not really needed but it made things nicer with the first transformer I used.

It works as expected:

The ratio is 5V / 0.8V = 0.16 , so that 1k I’ve put on the primary appears as 1k * (0.16^2) = 25.6 Ohm on the other side and matching to 50Ohm is as easy as putting a series resistor.

I already knew that the level shifter has a turn off delay of about 1.3uS compared to the output from the 4093 (look at that, it is 23 years old!). The main contributor to that is the last transistor (a PNP), as I just slapped a 1k resistor from base to emitter and called it a day. On the range of voltages I am interested even if the output latches the dissipation involved is way inside a safe zone, but the cost of that simplicity is that I am not able to bring it into cutoff just as fast. Replacing that with a 220 ohm improves things a bit but it is not the ultimate solution. Anyway, I like it as it is.