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AX3026CJ

RF POWER TRIODE

The AX3026CJ is a metal-ceramic triode, intended for use in industrial generators, oscillator output power up to 32 kW for frequencies up to 120 MHz . GENERAL DATA Electrical Filament : Thoriated tungstenum (see note 1) Voltage Vf 7 V Current If 115 A Characteristics Amplification Factor µ 20 Transconductance S 33 mA/V Direct interelectrode capacities Grid-Anode 26 pF Grid-Cathode 59 pF Anode-Cathode 1,5 pF Mechanical Overall dimensions

Length 303 mm Diameter 150 mm Approximative weight 7 kg Mounting position vertical, anode up or down

Cooling type water Accessories Internal cathode terminal Ref. 8311 219 24401 External cathode terminal Ref. 8311 219 24601 Cathode connecting strip (2 per tube) Ref. 8311 219 25201 Grid terminal for f ? 10 MHz Ref. 8311 219 32201 Grid terminal for f ? 10 MHz Ref. 8311 219 25001 Water connector (2 per tube) Ref. 8311 219 26601

COVIMAG Z.I. La Marquisie

Avenue du 4 juillet 1776 19101 BRIVE Cedex - France

Tel : + 33 (0)5 55 86 49 50

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January 2003

AX3026CJ

Cooling To obtain optimum life, the seal/envelope temperature under normal operating conditions should be kept below 220 °C at any point. It is recommended to use an additional cooling by an air flow rate of approximately 0,7 m3/min channeled o n the tube terminal side. If the tube is mounted in normal position (anode down), water in the anode cooling jacket has to flow in the arrow-marked direction. If the tube is mounted in reverse position (anode up), input and output water connections should be reversed. The water cooling diagram applies to water inlet temperature t1 = 35 °C

Pressure conversion factor : 100 kPa = 1 atm = 1 bar Note 1 The cathodes consist of thoriated tungsten and are directly heated. No RF voltage is permitted between the two heater terminals of the tube since this would result in an additional heating of the cathode. For this reason, a capacitive bridging of the cathode is generally required. To reduce resonance effects, a low-ohmic resistor should be provided at the heater terminals. Heater voltage The heater power is primarily determined by the heater voltage applied to the cathode. The rated heater voltage is the maximum voltage required by a new tube to supply its rated output power. During operation, the heater voltage value should be kept as precisely as possible ; the utmost average deviation from the rated value may only amount to + 1 % or - 3%. Temporary deviations between + 5 and - 10% are permitted. Since higher voltage variations may occur in industrial power systems, stabilization of the heater voltage will usually be necessary. The heater voltage should be set by means of an rms voltmeter, such as a moving iron meter of 0.5% accuracy, with the measurements being directly carried out at the cathode terminals. An inaccurately set heater voltage has - due to physical principles - the following effects : on one hand, the cathode service life is shortened by overheating while underheating, on the other hand, reduces the emission capability and thereby the possible peak cathode current, thus causing a power decrease. Heater current The heater current of a new tube may deviate from the rated value within a set tolerance range. During service life decarburization of the cathode thoriated tungsten filaments causes an increasing heater current which may exceed the initial value by up to 15 %. This has to be considered when dimensioning the heater transformer.

COVIMAG Z.I. La Marquisie

Avenue du 4 juillet 1776 19101 BRIVE Cedex - France

Tel : + 33 (0)5 55 86 49 50

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January 2003

AX3026CJ

OSCILLATOR FOR INDUSTRIAL APPLICATION Anode voltage from three-phase bridge rectifier Maximum ratings Frequency f 40 80 120 MHz DC anode voltage Va 12 11 9 kV DC grid voltage Vg - 1,5 - 1,5 - 1,5 kV DC cathode current Ik 6 6 6 A Peak cathode current Ikp 30 30 30 A DC grid current Ig 1,1 1 0,9 A No load DC grid current Ignl 1,4 1,3 1,1 A Anode dissipation Wa 25 25 25 kW Grid dissipation Wg 550 450 350 W Grid resistor at blocked tube Rgc 15 15 15 k? Operating charactgeristics Frequency f ? 40 ? 40 ? 80 ? 120 ? 120 MHz Output power (see note 2) Wosc 32 25 27,5 21 14 kW DC anode voltage Va 10 8 10 8 8 kV DC grid voltage Vg - 800 - 650 - 800 - 650 - 750 V Peak RF grid voltage Vgp 1200 1050 1160 1000 1050 V Feedback factor Vgp/Vap 13.5 15 13 14.5 14 % DC anode current Ia 4.1 4.2 3.5 3.5 2.1 A DC grid current Ig 700 760 580 600 470 mA Grid resistance Rg 1.15 0.86 1.4 1.1 1.6 k? Anode input power Wia 41 33.6 35 28 16.8 kW Drive power Wdrive 800 760 650 570 470 W Anode dissipation Wa 8.2 7.8 6.8 6.4 2.3 kW Grid dissipation Wg 240 260 180 180 120 W Oscillator efficiency ? osc 78 74.5 78.5 75 83 % Anode load resistance Ra 1.3 1 1.5 1.2 2.1 k? Note 2 : Not considering circuit losses

COVIMAG Z.I. La Marquisie

Avenue du 4 juillet 1776 19101 BRIVE Cedex - France

Tel : + 33 (0)5 55 86 49 50

January 2003

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RF Power triode AX3026CJ

Constant current characteristics

COVIMAG Z.I. La Marquisie

Avenue du 4 juillet 1776 19101 BRIVE Cedex - France

Tel : + 33 (05) 55 86 49 50 January 2003

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Va

600

500

400

300

200

100

0

-100

-200

-300

-400

-500

-600

-700

-800

Vg

Vg=f(Va) V

Ia=

20A

15A

10A

5A

3A

1A

0.4A0.1A

0A

0 1 2 3 4 5 6 7 8 9 10 11 12 13kV

Ia

Ig

Ig=7A

6A

5A 4A

3A 2A

1A 0.5A

0.4

0.3A

0.2A 0A

RF Power triode AX3026CJ

Cooling water diagram

COVIMAG Z.I. La Marquisie

Avenue du 4 juillet 1776 19101 BRIVE Cedex - France

Tel : + 33 (05) 55 86 49 50 January 2003

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Q L/mn

20

18

16

14

12

10

8

6

4

2

0 0 5 10 15 20 25kW

P

Kpa

40

30

20

10

0

t2 °C

100

90

80

70

60

50

40

30

20

10

0

Anode dissipation Wa

T1=35°C

Q

p

t2