| GENERAL DESCRIPTION |
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The 4CX350A / 8321 is a compact radial beam tetrode with maximum plate dissipation of 350 watts and is intended for Class-AB, audio or rf amplifier service. The tube is externally identical to the 4CX250B / 8321 but contains rugged internal construction features. Amplification factor and cathode area have been increased over the 4CX250B / 8321 to give higher transconductance and figure of merit. The 4CX350A / 8321 is used at 6.0 volts. The tube is of ceramic and metal construction and is recommended for new equipment design. |
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| TECHNICAL SPECIFICATIONS | |
| Plate Dissipation (Max.) | 350 watts |
| Grid Dissipation (Max.) | 0 watts |
| Screen Dissipation (Max.) | 8 watts |
| Frequency for Max. Ratings (CW) | 110 MHz |
| Cooling | Forced Air |
| Cathode Voltage Current |
Oxide-coated Unipotential 6.0 Volts 2.9 Amperes |
| Capacitances (Grounded Cath. Connection) Input Output Feed-through |
23.6 pF 5.6 pF 0.03 pF |
| Amplification Factor (g1-g2) | 13 |
| Transconductance | 22,000 μmhos |
| Base | 9-Pin Special |
| Recommended Air-System Socket | SK-600A |
| Recommended Air Chimney | SK-606 |
| Maximum Seal & Anode Core Temperature | 250°C |
| Maximum Length | 2.47 in; 62.60 mm |
| Maximum Diameter | 1.64 in; 41.60 mm |
| Weight (approximate) | 4 oz; 113 gm |
| Operating Position | Any |
| Specifications may change without notice | |
| THIS TUBE IS USED IN THE FOLLOWING SHORTWAVE BROADCAST TRANSMITTERS | ||
| Manufacturer | Transmitter specifications | Power in kW |
| Collins | 208U-3 | 3 |
| 208U-10 | 10 | |
| 205J-1 | 45 | |
| 821A-1 | 250 | |
| 821A-2 | 250 | |
| Continental Electronics | 416 D | 10 |
| 416 E | 10 | |
| HCJB Global | HC 500 | 500 |
| RIZ Transmitters | OR 5 K-01/A | 5 |
| THIS TUBE IS AVAILABLE FROM | ||
| Manufacturer | Rebuilder | Distributor |
| Eimac | Richardson Electronics | |
| Penta Laboratories | ||
| 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 |