Hg-Arc Lamp, Pulse Excitation.

Full power output over a period of 5000 hours was achieved with an electrode-less B-H6 type lamp with 800 W, CW , 2.45 GHz excitation. Devitrification became visible after 1500 h. Pulse excitation was achieved for simmering 2.45 GHz power levels of 500, 600 and 700 W by capacitor discharge producing 5 microsecs long pulses with peak currents of 200 and 400 A. Little sputtering appeared up to 1000000 200 A pulses at a rate of 10 pps. Stress cracks in the envelope seem to be the life limiting mechanisms for this type of pulsing. 200 MHz pulse excitation with 40 mA DC simmering and without forced air cooling was also achieved. The WWII radar transmitter used was unreliable and furnished only 40 KW pulses. Author