7Q7 — Hexode, Loctal | TubeofileKnown Equivalents & Substitutes
CV899
Similar Tubes (Not Drop-In Compatible)
14Q7
Same Loctal pinout but 12.6V heater — not interchangeable without heater rewiringSuccessor pentagrid converter in miniature B7G base — electrically similar but different socket Electrically similar pentagrid converter but Octal base — not pin-compatible with Loctal 7B8
Predecessor pentagrid converter in Loctal — different characteristicsElectrical Specifications
Absolute Maximum
Anode Voltage (max)Max Plate Voltage300V
Anode Dissipation (max)Max Plate Dissipation1W
Screen Voltage (max)Max Screen Voltage100V
Typical Operating
Anode Voltage (typical)Plate Voltage250V
Notes
- GE Essential Characteristics: converter service at Va=250V, Vg2=100V, Vg1=-2V gives Ia=3.5mA, Ig2=8.5mA, gm=550 umhos (conversion), rp=1 Mohm.
- Max plate dissipation 1.0W, max plate voltage 300V, max screen voltage 100V.
- Raytheon lists substitute types 7I7, 7A8, 7B8.
- Brans cross-references with 6BE6, 12BE6, and CV899.
Pin Layout — Loctal
1Heater
2Plate
3Grids 2 & 4 (Screen)
4
Grid 1 Bias VoltageControl Grid Voltage
-2V
Screen VoltageScreen Voltage (Grids 2 & 4)100V
Anode CurrentPlate Current3.5mA
Screen CurrentScreen Current8.5mA
Anode ResistancePlate Resistance1,000,000Ω
TransconductanceConversion Transconductance0.55mA/V
Heater
Heater VoltageHeater Voltage6.3V
Heater CurrentHeater Current0.3A
Grid 5 (Suppressor)
6Grid 1 (Oscillator Grid)