Description
BR1647F is a power triode of coaxial ceramic-metal construction. It is intended primarily for industrial RF heating machines. Anode is cooled by forced-air.
Electrical Characteristics of BR1647F
Filament: Thoriated tungsten
Filament voltage (see note 1): 8.2 V
Filament Current: 238 A
Surge filament current (peak) (See note 2): 1200 A max
Filament cold resistance: 4.0 mΩ
Peak usable cathode current: 70 A
Amplification factor (Va = 10 kV, Ia = 5.0 A): 28
Mutual conductance (Va = 10 kV, Ia = 5.0 A): 51 mA/V
Inter-electrode capacitances:
Grid to anode: 47 pF
Grid to filament: 126 pF
Anode to filament: 2.0 pF
Mechanical characteristics of BR1647F
Overall dimensions: See outline drawing
Net weight: 16 kg approx, 35 pounds approx
Mounting position: Vertical, either way up
Accessories
Thermal fuse: PA85G
Cathode Connector: PA830
Note: For frequencies above 2 MHz, PA830 should be used in conjunction with a strip connection to provide a low inductance cathode return.
Cooling
The BR1647F air cooling requirements are shown on page 5. The required air flow should be delivered through the radiator immediately before and during the application of any voltages. Filament power, anode power and air flow may be removed simultaneously.
The temperature of the seals and envelope must not exceed 200 °C. Cooling of the seals by low velocity air flow is required.
Radio Frequency Oscillator For Industrial Service
(Class C Conditions, One Tube)
Maximum Ratings (Absolute Values) of BR1647F
Frequency: 30 MHz
Anode voltage: 13 kV max
Anode input power: 150 kW max
Anode dissipation: 50 kW
Grid voltage (negative value): 2.0 kV max
Grid Current
On load: 3.0 A max
Off load: 3.8 A max
Grid dissipation: 1.8 kW max
Grid circuit resistance: 10 kΩ max
Cathode current: 16 A max
Typical Operating Conditions of BR1647F
| Parameter | 8 kV | 10 kV | 12 kV |
|---|---|---|---|
| Frequency | 30 | 30 | 30 MHz |
| Anode Voltage | 8.0 | 10 | 12 kV |
| Anode Current | 8.0 | 10 | 10.4 A |
| Anode Dissipation | 13.6 | 21.1 | 21.3 kW |
| Grid Voltage | -580 | -700 | -860 V |
| Grid Resistor | 322 | 318 | 390 Ω |
| Grid Current (On Load) | 1.8 | 2.2 | 2.2 A |
| Grid Current (Off Load) | 2.8 | 3.4 | 3.4 A |
| Grid Dissipation | 711 | 1100 | 1100 W |
| Feedback Ratio (See note 4) | 13.7 | 13 | 12.2 % |
| Drive Power | 1.7 | 2.6 | 3.0 kW |
| Output Power | 51.9 | 84.6 | 102.9 kW |
| Efficiency | 79.3 | 80 | 82.8 % |
| Oscillator Output Power (See note 5) | 50.2 | 82 | 100 kW |
Notes
1. Temporary fluctuations up to +5% or −10% in filament voltage are permissible.
2. The filament current must not exceed 1200 A at any time.
3. If the tube is mounted with the anode uppermost, the water inlet and outlet connections should be reversed.
4. Feedback ratio = Vg(pk) / Va(pk) × 100.
5. Oscillator Output Power = Output Power − Drive Power.
