Type | Substitutes | Base Diagram |
---|---|---|
4BQ7A | 4BC8, 4BZ7, 4BZ8, 4KN8, 4BS8, 4BX8, 5BK7A | |
Web References | 4BQ7A (RCA (HB3)) @ Franks Electron Tubes 4BQ7A (General Electric) @ Franks Electron Tubes 4BQ7A (Tung-Sol) @ Franks Electron Tubes 4BQ7A (RCA (RC30)) @ Franks Electron Tubes 4BQ7A @ RadioMuseum.org |
Bulb | T-61/2 |
Base | Small Button 9-Pin |
Basing | 9AJ |
Mounting Position | Any |
Heater Voltage | 4.2 | Volts |
Heater Current | 600 | Ma |
Heater Warm-up Time | 11 | Seconds |
Maximum Peak Heater-Cathode Voltage | 200 | Volts |
Grid to Plate | 1.2 | 1.2 | ��f |
Input | 2.6 |   | ��f |
Output | 1.2 |   | ��f |
Plate to Cathode | 0.12 | 0.12 | ��f |
Heater to Cathode | 2.6 | 2.6 | ��f |
Plate to Plate | 0.010 | 0.010 | ��f |
Plate Section 2 Plate and Grid Section 1 | 0.024 | 0.024 | ��f |
Input | 5.0 | ��f |
Output | 2.2 | ��f |
Plate Voltage | 250 | Volts |
Plate Dissipation | 2 | Watts |
Cathode Current | 20 | Ma |
Grid Circuit Resistance | 0.5 | Megohm |
Plate Voltage | 150 | Volts |
Cathode Bias Resistor | 220 | Ohms |
Plate Current | 9 | Ma |
Transconductance | 6400 | �mhos |
Amplification Factor | 38 | X |
Grid Voltage for Ib=100�a (approx.) | -6.5 | Volts |
  | Section 1 | Section 2 |   |
Plate Supply Voltage | 250 | 250 | Volts |
Plate Voltage | 135 | 115 | Volts |
Negative Grid Voltage | -1 |   | Volts |
Cathode Bias Resistor | 100 |   | Ohms |
Grid Resistor |   | 0.5 | Megohm |
Plate Current | 10 | 10 | Ma |
Grid Current | 0 | 0 | Ma |
Grid Voltage for Ib=10�a (approx.) | -14 |   | Volts |
Plate Voltage | 150 | Volts |
Grid Voltage | -2 | Volts |
Cathode Bias Resistor (Common to both sections) | 100 | Ohms |
Plate Current | 10 | Ma |
1 | RETMA shield No. 315 |
2 | Section No. 1 connects to Pins 6, 7 and 8. Section No. 2 connects to Pins 1, 2 and 3. |
3 | Under cutoff conditions, in r f grounded grid circuits with direct coupled drive, this voltage may be as high as 300 volts. |
4 | Section No. 1 (Driver) is directly coupled to Section No. 2 (Driven Grounded Grid Amplifier) |