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

PJ300M
28 / 28 User Manual Rev. 7.0 - 25/07/03
10.5 Low Pass Filter adjustment
No adjustments are required inside the low pass filter module since it is a factory
adjusted device.
In case of replacement of a unit, perform the following operations:
• Reconnect all the modules and turn the trimmer TR1 of the filter completely
clockwise.
• Follow the setup shown in the figure, that comprises a dummy load (P>300W at
50 Ohm) with a trough wattmeter in series, to verify the power delivered by the
amplifier.
• Connect to the RF input connector of the amplifier a suitable exciter able to deliver
a variable power of 20 W max.
• Connect one of the two connectors alarms/interlock of the amplifier to the
appropriate connector of the exciter.
• Switch on the amplifier PJ300M and the exciter and wait for the exciter to lock on
the working frequency.
• Slowly increase the drive power to obtain 325W of otuput power.
• Check with a spectrum analyzer connected to a suitable directional coupler that
the harmonics level is below -75 dBc.
• Adjust the trimpot TR1 in the low pass filter until the protection system is triggered.
• It is advisable to repeat the regulation of FWD and RFL power measurement on
the alarm card as described before.