4JW8

Plate resistance

20000 Ω

Transconductance

0.0035 S

Amplification factor

70

Max plate voltage

250 V

Max plate dissipation

1.4 W

Max cathode current

10 mA

General Electric JEDEC states 4JW8 is electrically identical to 6JW8 apart from 4.5 V 600 mA heater rating and approximately 11-second controlled warm-up. Separate triode section serves horizontal AFC/reactance-tube operation: manufacturer maximum plate voltage 250 V, dissipation 1.4 W, cathode current 10 mA. Typical at Va 200 V, Vg -2 V: gm 3500 µmhos (0.0035 S), amplification factor 70, approximately 20 kΩ input/plate resistance as reported in 6JW8 characteristics. These characteristic values are typical, not maximum ratings. Triode interelectrode capacitances supplied by 6JW8 manufacturer; separate pentode is section 2.

Transconductance

0.0055 S

Max plate voltage

250 V

Max screen voltage

250 V

Max plate dissipation

1.2 W

Max screen dissipation

0.8 W

Max cathode current

15 mA

GE JEDEC 4JW8 electrically identical to 6JW8 except heater (4.5 V, 0.6 A, controlled warm-up approximately 11 seconds). Pentode provides television horizontal-oscillator service while separate triode serves reactance/AFC circuitry. Design-center operating maxima plate voltage 250 V, screen 250 V, plate dissipation 1.2 W, screen dissipation 0.8 W, cathode current 15 mA. Zero-plate-current voltage allowances 550 V are separate, not ordinary operating maxima. Typical pentode at Va 100 V, Vg2 100 V, Vg1 -1 V: Ia 6 mA, Ig2 1.7 mA, gm 5500 µmhos (0.0055 S). Published input, feedback, and interelectrode capacitances. Screen rating may depend on published operating conditions.