I had misfortune and snapped off transistor's leg beyond repair. Tektronix part number 151-1108-00
Unfortunately this is enhanced N-Channel Mosfet Q758 (VN99AK) in high amplitude section.
Some parameters according to data sheet: VDS 90V, IDS 2A, VGS is low 0.8-2v with RDS 5 ohm.
I would imagine, it would be very hard to get one. Any idea if I could use something modern instead.
Perhaps someone has PG-506 parts unit and could sell this transistor to me.
Any help is appreciated.