Electrically identical sections but 12.6V/0.3A heater
6SN7GT
Electrically identical sections but 6.3V/0.6A heater — not a drop-in replacement in series-string heater circuits
Electrical Specifications
Absolute Maximum
Anode Voltage (max)Anode Voltage (max)300V
Anode Dissipation (max)Anode Dissipation (max, per section)2.5W
Cathode Current (max)Cathode Current (max)20mA
Heater-to-Cathode Voltage (max)Heater-to-Cathode Voltage (max)90V
Max Grid ResistorMax Grid Resistor
Heater
Heater VoltageHeater Voltage25V
Heater CurrentHeater Current0.15A
Notes
RCA datasheet states: 'Curves for Type 1633 are the same as for the 6J5, and 6SN7-GT.' The per-section characteristics are identical to one section of a 6SN7GT.
Designed for 25-volt series-string heater circuits commonly used in AC/DC radios of the 1940s. The 25V/0.15A heater is not interchangeable with 6.3V or 12.6V heater variants without rewiring.
The datasheet specifies the tube is 'for applications critical as to matching of the two triode units', indicating factory-selected matched sections.
Maximum grid circuit resistance must not exceed 1.0 megohm under maximum rated conditions per unit.
Pin Layout — Octal
1Control Grid (section 2)
2Anode (section 2)
3Cathode (section 2)
4
Socket-Compatible Tubes ⚠ Not electrically compatible