Class A AF amplifier/modulator: Va_max=2500V, Pa_max=600W. At Va=1500V: Vg=-40V, Ia=175mA, ra=1800 Ohm, rl=3700 Ohm, Po=46W. At Va=2000V: Vg=-65V, Ia=270mA, ra=3100 Ohm, rl=3700 Ohm (sic), Po=100W. At Va=2500V: Vg=-92V, Ia=240mA, ra=1600 Ohm, rl=5000 Ohm, Po=160W.
Class B AF amplifier/modulator (2 tubes): Va_max=3000V, Pa_max=750W. At Va=2000V: max-signal Ia per tube=1.7A, rl per tube=650 Ohm, Po=20W driving, 2.2W output. At Va=2500V: max-signal Ia=1.4A, rl=1000 Ohm, Po=12 approx.W driving, 2.3W output. At Va=3000V: max-signal Ia=1.2A, rl=1400 Ohm.
Class B RF power amplifier (telephony): Va_max=2500V, Pa_max=750W per tube. At Va=2000V: Vg=-85V, peak RF grid voltage=140V, Ia=0.475A, Po=275W approx.
Class C plate-modulated RF amplifier (telephony): Va_max=2000V, Pa_max=500W. Capable of 900W output at Va=1500V and 1250W at Va=2000V.
Class C RF oscillator (telegraphy, key-down): Va_max=2500V, Pa_max=750W. Capable of 900W output at Va=1500V and up to 1700W at Va=2500V.
Maximum plate current is 1000 mA (1A). Requires forced-air cooling at full ratings.
Pin Layout — Jumbo3
1Filament
2Grid
3Filament
TCTop Cap —Plate (Top Cap)
Socket-Compatible Tubes ⚠ Not electrically compatible