Centurion Model 422 Linear Amplifier

QSK amplifier using 3-500Z tubes. The RF deck and power supply are combined into a single desk top cabinet. The power output is rated at 1300 watts on ssb, 1000 watts cw and 650 watts using “key- down” modes. Drive required for full power ssb operation is 100 watts. The duty cycle is 50%.

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• Bob Hutchinson, N5CNN

• Meter lamp replacement: NAPA auto parts CM 756, 14V 80ma
• non-zero plate current at idle

• Archived Ten-Tec Web Page

• Band Coverage: 1.8 - 2.0, 3.2 - 4.7, 6.5 - 10.3, 13.4 - 19.6, 17.6 - 21.5 MHz, 21.5 - 29.7 MHz after authorized modification.

• Input Power: 2000 watts, maximum.

• Power Output: 1300 watts SSB, 1000 watts CW, RTTY and SSTV 650 watts, 50% duty cycle.

• Drive Power: 100 watts for full rated output.

• Efficiency: 50 - 65%, depending on frequency and load impedance.

• Input/Output Impedances: 50 Ohms, unbalanced, SWR < 2:1.

• Distortion: -35 dB from 1 kw RF output level.

• Harmonics: -50 dB typical.

• CW Break-in: QSK capable, Relay switching.

• Tube Complement: Two Eimac 3-500Z.

• Power Amplifier Circuit: Class AB2, grounded grid.

• Plate Voltage: 3100 volts, no load. 2600 volts, full load.

• Cooling: Forced air with full chassis air flow.

• Metering: Dedicated plate current meter. Selectable multi-meter for plate voltage, grid current, forward or reflected power. Ten element LED bargraph display for peak power indication.

• Front Panel Status Indicators: Standby, operator, transmit.

• Primary Power: 220 - 250 VAC @ 15 A, 110 - 125 VAC @ 30 A, 50/60 Hz. For full power operation, 220 - 250 VAC strongly recommended.

• Circuit Protection: Primary line fuses. Plate transformer primary interlock and high voltage shorting bar.

• Front Panel Controls: Power on/off, standby/operate, control mode select (QSK - PTT/VOX), plate TUNE and LOAD, band switch, meter switch.

• Tune and Load Controls: 6:1 vernier drives with calibrated dial skirts.

• Construction: Aluminum chassis, front and rear panels, interior partitions and top and bottom covers.

• Size: HWD 8.25" x 15.25" x 18.5" (20.3 x 38.7 x 46.9 cm)

• Weight: 47 lbs (21.3 kg)

Note for older 422 Centurion amp owners: Using an older Centurion with the newest Ten-Tec HF transceivers - Pegasus, Jupiter, and Orion - may require a small modification to the QSK board in older Centurion amps for proper QSK CW keying. Short diode D2 (red diode, 1N4148, next to Q1) with a jumper wire. The current 422B does not require this modification. For questions, please consult our service department at (865) 428-0364 or via email at service@tentec.com