The project has received all the 5400 dual-transistors (with the hope that 10800 transistors will be enough, but you never know, right ?) and already a question arises : how to test them ?

I have the fast DDS but the BFS480 is one notch higher. So the idea is to see if it can be used for an avalanche pulse generator to generate sub-nanosecond signals ?

I have seen the venerable 2N2369 used for this purpose but it's a 50-years old part. The BFS480 is not only faster, but also has lower breakdown voltage, which is a nice thing, no ? A dumb oscillator and simple charge pump should be enough to generate the low-current higher voltage that such a circuit needs.

Some background and references

• @Jenny List has implemented a #Avalanche Pulse Generator with a 2N3904, which is meant for higher powered applications. "The 2N3904 requires a high voltage to operate in avalanche mode, well over 100V."
• alexwhittemore tried to make one too: #Avalanche
  
• Kerry Wong's avalanche pulse generator
• Jim William's AN72, AN47 and AN94, see also in EDN Simple nanosecond-width pulse generator provides high performance
• Andrew Holme's own circuit (even more scopeporn)
• An avalancher used to drive nanosecond lasers
• EEVBLOG#306 (2012) citing http://people.osmocom.org/tnt/hw/pulse_gen/
• A fancy version at http://www.siliconvalleygarage.com/projects/picosecond-pulser.html
• (your link here)

but I have never seen a low power UHF transistor.

AN72 however covers the "balancing" technique, using a pulse transformer to create a symmetrical pulse. This will be needed to test the transmission lines of the clock and control pulses...