7AD7 — Power Pentode, Loctal | Tubeofile | Tubeofile
TUBEOFILE
← Browse Medium quality — at least 60% of universal parameters and pins are present, but some key data is missing. Verify specific values against datasheets before critical use.
Known Equivalents & Substitutes
No known equivalents. If you know of any, use the ⚑ Report Issue button above.
Similar Tubes (Not Drop-In Compatible)
Brans lists in same group — similar sharp-cutoff pentode but different base (Noval vs Loctal) Brans lists in same group — similar characteristics but Noval base Brans lists in same group — similar power pentode but Noval base, different era Brans lists in same group — European equivalent type but different base Electrical Specifications
Absolute Maximum
Anode Voltage (max) Max Plate Voltage 300V
Anode Dissipation (max) Max Plate Dissipation 10W
Screen Voltage (max) Max Screen Voltage 300V
Screen Dissipation (max) Max Screen Dissipation 1.2W
Heater-to-Cathode Voltage (max)
Notes
Tung-Sol datasheet marked as 'Tentative Data' (1948). Two typical operating conditions given: Class A1 amplifier (Va=300V, Vg2=150V) and Class A1 television amplifier (Va=300V, Vg2=125V). Maximum grid #4 circuit resistance: 0.25 Mohm (fixed bias), 1 Mohm (self-bias). GE Essential Characteristics lists max plate dissipation as 10W, screen voltage max 150V. Grid #3 voltage connected to pin #7 at socket (cathode connection). Pin Layout — Loctal
1 2 3 4 5 6 7 8
1 Heater
2 Plate
3 Screen Grid (g2)
4
Socket-Compatible Tubes ⚠ Not electrically compatible
Max Heater-Cathode Voltage
90V
Typical Operating
Anode Voltage (typical) Plate Voltage 300V
Grid 1 Bias Voltage Grid Voltage -3V
Anode Current Plate Current 28mA
Screen Voltage Screen Voltage 150V
Screen Current Screen Current 7mA
Anode Resistance Plate Resistance 300,000Ω
Transconductance Transconductance 9.5mA/V
Capacitances
Grid-to-Plate Capacitance Grid-Plate Capacitance 0.03pF
Input Capacitance Input Capacitance 11.5pF
Output Capacitance Output Capacitance 7.5pF
Heater
Heater Voltage Heater Voltage 6.3V
Heater Current Heater Current 0.6A
Grid #3 (connected to pin #7 at socket)
5 Grid #5 (connected to pin #7 at socket)