Copyright 2005 ISC Technologies
5.4 Checks and Adjustments
Your transmitter was completely checked out and performing within operating specifications
when it left the factory. Since signal levels, control voltages, and possible ac line voltage
may vary from those used in factory testing, the following system checks and adjustments
should be made when the equipment is initially placed into service.
5.5 Equipment Needed
The following tools and equipment will be required to install the 9T97A250 RF power am-
plifier.
•
ISC Technologies UHF 4-watt amplifier and DSP exciter.
•
Power supply: 28 Vdc 24 A minimum.
•
Directional wattmeter, 50 ohms, 5-watts full scale, 5% accuracy.
•
Directional wattrneter, 50 ohms, 250-watts full scale, 5% accuracy.
•
50-ohm termination 250 W.
•
DC voltmeter: 30 Vdc minimum.
•
DC ammeter: 25 A full scale, 2.5% accuracy.
•
Rack mount hardware.
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Cables with appropriate connectors.
•
One jumper: 0.1 spacing, (270-0501).
5.6 Procedure
1. Install the exciter shelf, power supply, and power amplifier into the rack, but do not
interconnect.
2. Connect the voltmeter to the power supply. Check that polarity is correct. Check that the
leads are not shorted out.
3. Switch ON the power supply and check that the voltage is 28 Vdc within 0.1 Vdc. Adjust
the power supply if necessary.
4. Switch OFF power supply.
5. Disconnect voltmeter leads after the power supply has discharged.
6. Connect the power supply to the barrier strip on the rear of the power amplifier. Check
that polarity is correct.
7. Remove placard and turn ON power supply. Check that the green power light on the
front panel of the power amplifier is illuminated, and the fan is operating.
8. If the LED is not on, turn OFF the power supply and check fuses and polarity of the
cables. If the LED still does not illuminate, or the fan does not start. contact ISC
Technologies Customer Service before continuing.
9. Switch OFF the power supply and connect the exciter output through the 5-watt F.S.
directional wattmeter to the 5-watt R.F. load.
10. Switch ON the power supply, and key the exciter. Check that about 4.0 watts +/-0.2
watts is produced when the exciter is keyed. Switch OFF the exciter and disconnect the 5-
watt R.F. load.
