Electrically identical (same mu, ra, gm) but UX4 base — 1H4G is the Octal-base replacement
Electrical Specifications
Absolute Maximum
Anode Voltage (max)Plate Voltage (max)180V
Max Grid ResistorGrid Circuit Resistance (max)2MΩ
Typical Operating
Anode Voltage (typical)Plate Voltage (typical, Class A1)135V
Grid 1 Bias VoltageGrid Voltage (typical, Class A1)-9V
Anode CurrentPlate Current (typical, Class A1)3mA
Anode ResistancePlate Resistance10,300Ω
TransconductanceTransconductance
Capacitances
Grid-to-Plate CapacitanceGrid to Plate Capacitance5pF
Grid-to-Cathode CapacitanceGrid to Filament Capacitance3.6pF
Anode-to-Cathode CapacitancePlate to Filament Capacitance5pF
Heater
Heater VoltageFilament Voltage2V
Heater CurrentFilament Current0.06A
Notes
Tung-Sol datasheet states: 'With the exception of capacitances its ratings and characteristics are identical with those of the 30.'
Filament is DC only (battery supply). The 2.0V/0.06A filament is designed for single dry-cell operation.
With maximum signal, average DC plate current should not exceed 2.0 mA in Class A1 amplifier service.
Grid return is to negative end of filament (approximate). Datasheet notes this as approximate for all operating conditions.
Detector operation: grid-leak mode with 1-5 MΩ grid leak and 250 pF grid condenser at Va=45V; biased mode at Va=90-180V with grid return to negative filament.
1H4G and 1H4GT are glass envelope variants; same electrical tube.
Pin Layout — Octal
1No Connection
2Filament (+)
3Plate
4
Socket-Compatible Tubes ⚠ Not electrically compatible