SG-2000 MANUAL
178
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©1995, SGC, Inc.
TEL: (206) 746-6310 FAX: (206) 746-6384
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Reverse Voltage
(Rev E Boards ONLY)
Reverse the power supply connections on the LPA.
Watch the current meter on the power supply as you turn on the power supply.
Turn off the power supply if there is any current and troubleshoot the problem.
Increase the supply voltage to 40 V. Relay K14 should stay open all the time.
Reduce the voltage to zero and turn off the power supply.
23.2.5
Filter Bands Sweep
This test will check for the upper edge of the 6 low pass filters by sweeping
them using the Tracking Generator and Spectrum Analyzer.
Compare the values displayed on the Analyzer to the values on the Filter Band
Table below. The values should be within -0 to +10%.
Procedure:
Install F3 and keep F1 and F2 removed.
Connect the LPA Test Box to LPA as follows;
C3 to IC3 socket
C4 to IC4 socket
C15 to J15
Set the switches in Receive position, Power off.
Connect Tracking Generator RF Out to J9 (RCVR) and set it to 0 dB RF Out.
Connect Spectrum Analyzer RF In to output dummy load antenna and set it to
5 MHz/division, 10 dB input attenuation.