Description
BR1608F is power triode of coaxial ceramic-metal construction. It is intended primarily for industrial RF heating machines. Anode is forced-air cooled.
Electrical characteristics of BR1608F
Filament: Thoriated tungsten
Filament voltage: 12 Volts
Filament Current: 178 Amps
Surge filament current (peak): 890 A max
Filament cold resistance: 8.0 mΩ
Peak usable cathode current: 70 A
Amplification factor (Va = 10 kV, Ia = 5.0 A): 40
Mutual conductance (Va = 10 kV, Ia = 5.0 A): 80 mA/V
Inter-electrode capacitances:
Grid to anode: 47 pF
Grid to filament: 126 pF
Anode to filament: 2.0 pF
Mechanical characteristics of BR1608F
Overall dimensions: See outline drawing
Net weight: 16 kg (35 lbs) approx
Mounting position: Vertical, either way up
Accessories
Cathode Connector: PA830
For frequencies above 2 MHz, PA830 should be used in conjunction with a strip connection to provide a low inductance cathode return.
Cooling
The BR1608F air cooling requirements are shown on page 5 of the pdf data sheet. 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 BR1608F
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: 2.0 kW max
Grid circuit resistance: 10 kΩ max
Cathode current: 16 A max
Typical Operating Conditions of BR1608F
| Frequency | 30 | 30 | 30 MHz |
| Anode Voltage | 8.0 | 10 | 12 kV |
| Anode current | 8.0 | 10 | 12 A |
| Anode dissipation | 12.2 | 17.3 | 22.6 kW |
| Grid Voltage | -500 | -630 | -800 V |
| Grid resistor | 333 | 315 | 296 Ω |
| Grid current, on load | 1.5 | 2.0 | 2.7 A |
| Grid Current, off load | 2.4 | 3.3 | 3.5 A |
| Grid dissipation | 592 | 947 | 1500 W |
| Feedback ratio (See note 3) | 12.1 | 11.8 | 12 % |
| Drive Power | 1.4 | 2.2 | 3.6 kW |
| Output Power | 51.9 | 82.7 | 121.4 kW |
| Efficiency | 81.0 | 82.7 | 84.3 % |
| Oscillator output power (See note 4) | 50.5 | 80.5 | 117.8 kW |
Note:
1. Temporary fluctuations up to +5% or –10% in filament voltage are permissible.
2. The filament current of BR1608F must not exceed 890 A, even momentarily, at any time.
3. The feedback ratio is defined as Vg(pk)/Va(pk) × 100 where Vg(pk) = peak R.F. grid voltage in volts and Va(pk) = peak R.F. anode voltage in volts.
4. Oscillator output power = Pout – Pdrive where Pout = output power of tube to anode circuit and Pdrive = drive power fed back to grid circuit.
