R.V.R. Elettronica PJ300M, Руководство пользователя, Страница: 31 / 34

PJ300M
25 / 28 User Manual Rev. 7.0 - 25/07/03
10. Internal Adjustment
10.1 Power Supply Adjustment (PSSW5010)
The power supply module is a factory adjusted device, and doesn’t need normally
any adjustment. If it has been necessary to substitute or repair the module, it is useful
to do the following tests and adjustments:
• Disconnect CN1 from the RF power module.
• For safety, connect a suitable dummy load (P>300W on 50 Ohm) to the amplifier
output and switch the amplifier on.
• Verify that the output voltage of the power supply is 50V using a digital multimeter
connected to pins 1-2 and 3-4 of connector JP3 and, if necessary, adjust the
value using the trimmer R15 of the power supply.
• Put the rotating selector of the analog meter on the position “V” and verify that the
voltage shown is 50V. You can adjust the voltage reading operating on trimmer
R14 placed of the alarms card.
• Verify that test point TP2 is present a voltage of 5.0V; if this value is different,
adjust R59 to obtain the correct voltage.
• Switch off the amplifier and reconnect the power supply to the RF module.
10.2 R.F. Power Amplifier Module Adjustment
After you have changed the power amplifier module perform the following operations:
• Connect CN1 (coming from power supply) to the RF module.
• Connect the input connector J1 to PJ300M RF input connector and the output J2
to the input connector J1 of low pass filter.
• See setup shown in figure, that comprises a dummy load (P>300W at 50 Ohm)
with a wattmeter in series, to verify the delivered power of the amplifier.
• Connect to the RF input connector of the amplifier an exciter able to deliver a
variable power of 20 W max.
• Connect the alarms/interlock connector to the appropriate connector on the exciter.
• Set the output power of the exciter to its minimum value.
• Switch on the PJ300M, keeping off the exciter and measure the quiescent current
of the module. At working temperature, an RF module has to drain approx 200
mA. If the current is different from this value, use trimmer R20 on the module to
compensate the difference.