This is the first trial for me to get microwave oscillation of Klystron. The klystron tube requires three voltage, heater, resonator, and reflector. Heater voltage is simply generated by switching AC/DC, and -105V reflector voltage is generated by VR105-MT voltage regulator tube (in the following movie, I am saying -75 V, but the correct one is -105V DC) through just rectifying AC100V to DC, and resonator voltage is generated by external DC power supply. As you see, YES it is working!