| GENERAL DESCRIPTION |
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The 4-400A / 8438 / QB4/1100GA / RS 1002 A is a compact, ruggedly constructed power tetrode having a maximum plate dissipation rating of 400 watts. It is intended for use as amplifier, oscillator or modulator. The low grid-plate capacitance of this tetrode coupled with its low driving-power requirement allows considerable simplification of the associated circuit and driver stage. The 4-400A / 8438 / QB4/1100GA / RS 1002 A is cooled by radiation from the plate and by circulation of forced-air through the base, around the envelope, and over the plate seal. Cooling can be greatly simplified by using an SK-400 Series Air System Socket and its accompanying glass chimney. This socket is designed to maintain the correct balance of cooling air between the component parts of the tube. |
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| TECHNICAL SPECIFICATIONS | |
| Plate Dissipation (Max.) | 400 watts |
| Screen Dissipation (Max.) | 35 watts |
| Grid Dissipation (Max.) | 10 watts |
| Frequency for Max. Ratings (CW) | 110 MHz |
| Cooling | Radiation & Forced Air |
| Filament Voltage Current |
Thoriated Tungsten 5.0 volts 14.7 amperes |
| Capacitances (Gnd. Cath. Connection) Input Output Feed-through |
12.5 pF 4.7 pF 0.12 pF |
| Amplification Factor (g1-g2) | 5.1 |
| Transconductance | 4000 μmhos |
| Base | 5-Pin Special |
| Recommended Air-System Socket | SK-410 |
| Recommended Air Chimney | SK-406 |
| Recommended Heat Dissipating Connector | HR-6 |
| Maximum Plate Seal Temperature | 225°C |
| Maximum Base Seal Temperature | 200°C |
| Maximum Length | 6.38 in; 162.00 mm |
| Maximum Diameter | 3.56 in; 90.40 mm |
| Weight (approximate) | 9.0 oz; 255 gm |
| Operating Position | Vertical, base up or down |
| Specifications may change without notice | |
| THIS TUBE IS USED IN THE FOLLOWING SHORTWAVE BROADCAST TRANSMITTERS | ||
| Manufacturer | Transmitter specifications | Power in kW |
| Bauer | 707 | 1 |
| CCA Electronics | AM 5,000F | 5 |
| AM 10,000F | 10 | |
| AM 15,000F | 15 | |
| Collins | 207A-1 | 10 |
| AN/FRT-5 | 15 | |
| 207B-1 | 35 | |
| AN/FRT-6 | 40 | |
| Elcor | SW-1 K | 1 |
| RCA | BHF-1A | 1 |
| THIS TUBE IS AVAILABLE FROM | ||
| Manufacturer | Rebuilder | Distributor |
| Covimag | Richardson Electronics | |
| Penta Laboratories | Vacuum Tubes, Inc. | |
| PRICE LEVEL (US$) | |||||
| 1 | 2 | 3 | 4 | 5 | 6 |
| 0 - 10 | 10 - 100 | 100 - 1000 | 1000 - 10,000 | 10,000 - 50,000 | 50,000 - 100,000 |