Description
BW1617J2F is a water cooled R.F. power triode of coaxial ceramic-metal construction. It is intended primarily for industrial R.F. heating machines. The tube comes with an integral water jacket.
Electrical Characteristics of BW1617J2F
Filament Thoriated tungsten
Filament voltage (see note 1) 6.3 V
Filament Current 160 A
Filament cold resistance 5.3 mΩ
Peak usable cathode current 30 A
Perveance 4.5 mA/V3/2
Amplification factor (Va = 2.25 kV, la = 1.0 A) 23
Mutual conductance (Va = 2.25 kV, la = 1.0 A) 40 mA/V
Grid to anode 36 pF
Grid to filament 78 pF
Anode to filament 2.0 pF
Electrical Characteristics of BW1617J2F
Overall dimensions See outline drawing
Net weight : 3.3 kg (7.3 pounds) approx
Mounting position Vertical, either way up
Accessories
Water coupling with BW1617J2F PA323A
Thermal fuse, available for BW1617J2F PA85E
Cathode Connector PA830
For frequencies above 2MHz, PA830 should be used in conjunction with a strip connection to provide a low inductance cathode return.
Cooling
BW617J2F has an integral water jacket. Minimum water cooling requirements are shown on page 7 higher rates of flow should be used where possible. The water pressure in the jacket must not exceed 6 atmospheres.
A thermal fuse, part number PA85E (melting point 103 ⁰C), is available for BW1617J2f to give protection against anode overheating. Two fuses should be used for maximum protection, screwed into the holes indicated on the anode mounting plate (see page 8). The fuses should be connected by a non-conducting cord to a suitable switching device; a tension of about 1 pound (450 g) should be applied to the fuses via the cord. If the temperature exceeds the safe limit, one or both fuses will release and the fuse cord is pulled outwards; this should actuate the switching device and remove all electrical supplies to the tube. Replacement fuse can be supplied to order.
Filament and Grid Seals
The temperature of the filament and grid seals must not exceed 200 °C. A flow of air of 15ft³/min (0.43m³/min) directed onto the terminals via a 1-inch (25 mm approx) diameter nozzle from a distance of 6 inches before and during the application of any voltages is usually adequate for limiting the temperature of the seals.
Radio Frequency Oscillator For Industrial Service (Class C Conditions, One Tube)
Maximum Ratings of BW1617J2F (Absolute Values)
Anode voltage : 10 kV max
Anode current : 6.0 Amp max
Anode dissipation (continuous or Intermittent service) : 15 kW max
Grid voltage (negative value) : –1.5 kV max
Off-load grid current : 1.6 A max
Grid dissipation : 600 W max
Frequency : 30 MHz max
Operating Conditions of BW1617J2F at Maximum Anode Current
| Anode Voltage | 9.5 | 9.0 | 8.0 | 7.0 | 6.0 kV |
| Grid Voltage | -800 | -775 | -700 | -600 | -520 V |
| From Grid Resistor | 800 | 720 | 640 | 540 | 445 Ω |
| Peak RF Grid Drive Voltage | 1150 | 1135 | 1050 | 940 | 860 V |
| Peak Positive Grid Voltage | 350 | 350 | 350 | 340 | 340 V |
| Anode Current | 5.0 | 5.0 | 5.0 | 5.0 | 5.0 A |
| Grid Current | 1.0 | 1.08 | 1.1 | 1.12 | 1.17 A |
| Anode Dissipation | 8.0 | 7.7 | 7.3 | 6.8 | 6.4 kW |
| Grid Dissipation | 350 | 390 | 380 | 380 | 398 W |
| Driving Power | 1150 | 1226 | 1155 | 1050 | 1006 W |
| Feedback Ratio (See note 2) | 13.1 | 13.7 | 14.5 | 15 | 16.1 % |
| Anode Output Power | 39.0 | 37.1 | 32.7 | 28.2 | 23.7 kW |
| Anode Efficiency | 83.1 | 82.7 | 81.6 | 80.6 | 78.7 % |
| Oscillator Output Power (See note 3) | 37.9 | 35.9 | 31.5 | 27.1 | 22.7 kW |
| Oscillator Efficiency | 80.7 | 80.0 | 78.9 | 77.6 | 75.4 % |
| Load Resistance | 980 | 920 | 805 | 700 | 600 Ω |
Operating Conditions of BW1617J2F with Reduced Input Power
| Anode Voltage | 9.5 | 9.0 | 8.0 | 7.0 | 6.0 kV |
| Grid Voltage | -800 | -775 | -700 | -600 | -520 V |
| From Grid Resistor | 1265 | 1225 | 1060 | 880 | 655 Ω |
| Peak RF Grid Drive Voltage | 1075 | 1050 | 975 | 860 | 795 V |
| Peak Positive Grid Voltage | 275 | 275 | 275 | 260 | 270 V |
| Anode Current | 3.5 | 3.5 | 3.5 | 3.5 | 3.5 A |
| Grid Current | 630 | 630 | 660 | 685 | 790 mA |
| Anode Dissipation | 5.3 | 5.1 | 4.7 | 4.6 | 4.1 kW |
| Grid Dissipation | 174 | 174 | 180 | 177 | 218 W |
| Driving Power | 680 | 665 | 645 | 587 | 630 W |
| Feedback Ratio (See note 2) | 12.3 | 12.7 | 13.4 | 13.7 | 14.7 % |
| Anode Output Power | 28.2 | 26.1 | 23.2 | 20.0 | 17.0 kW |
| Anode Efficiency | 84.2 | 83.7 | 83.0 | 81.3 | 80.8 % |
| Oscillator Output Power (See note 3) | 27.6 | 25.5 | 22.5 | 19.4 | 16.4 kW |
| Oscillator Efficiency | 82.2 | 81.5 | 80.7 | 80.6 | 77.9 % |
| Load Resistance | 1355 | 1300 | 1150 | 990 | 840 Ω |
NOTES
1. BW1617J2F must be operated at the stated filament voltage. Fluctuation in filament voltage must not exceed ±5%. The filament may be switched on at its operating voltage and no surge limiting devices need be incorporated in the filament circuit. The voltage drop in the integral filament leads is less than 1% of the filament voltage.
2. The feedback ratio is defined as Vg(pk)/Va(pk) X 100 where Vg(pk) = peak r.f. grid voltage in volts and Va(pk) = peak r.f. anode voltage in volts.
3. Oscillator output power = Pout – Pdrive
Where Pout = output power of tube to anode circuit and Pdrive = drive power fed back to grid circuit.
