| Type | Substitutes | Base Diagram |
|---|---|---|
| 1A7GT | 1B7, 1C7, 1D7, 1A7G, 1A7GT/G, 1B7G*, 1B7GT* |  |
| Notes: | * - Parallel filaments | |
| Web References | 1A7GT (RCA (HB3)) @ Franks Electron Tubes 1A7GT (Sylvania) @ Franks Electron Tubes 1A7GT (Tung-Sol) @ Franks Electron Tubes 1A7GT (Brimar) @ Franks Electron Tubes 1A7GT @ RadioMuseum.org | |
| Bulb | T-9 |
| Base | Small Wafer Octal 8-Pin With Metal Sleeve |
| Outline | 9-11 |
| Basing | 7Z |
| Mounting Position | Any |
| Filament Voltage D C | 1.4 | Volts |
| Filament Current | 50 | Ma |
| Plate Voltage | 110 | Volts |
| Grid No. 2 Voltage | 110 | Volts |
| Grid No. 3 And 5 Voltage | 60 | Volts |
| Grid No. 3 and 5 Supply Voltage | 110 | Volts |
| Cathode Current | 4.0Ma |
| Plate Voltage | 90 | Volts |
| Grid No. 3 and 5 Voltage1 | 45 | Volts |
| Grid No. 2 Voltage | 90 | Volts |
| Grid No. 4 Voltage (Control Grid)2 | 0 | Volts |
| Grid No. 1 Resistor (Osc. Grid) | 0.3 | Megohm |
| Plate Current | 0.6 | Ma |
| Grid No. 3 and 5 Current | 0.7 | Ma |
| Grid No. 2 Current | 1.2 | Ma |
| Grid No. 1 Current | 0.035 | Ma |
| Plate Resistance | 0.6 | Megohm |
| Total Cathode Current | 2.5 | Ma |
| Conversion Transconductance G4 at 0 Volts | 250 �mhos | |
| Conversion Transconductance G4 at -2 Volts | 50 �mhos | |
| Conversion Transconductance G4 at -3 Volts | 5 �mhos |
| 1 | Obtained preferably by using a properly by-passed 70,000 ohm resistor in series with a 90 volt supply. |
| 2 | A resistance of at least 1.0 Megohm should be in the grid return to negative filament pin. |