Cisco GainMaker Optoelectronic Node 1GHz with 65 86 MHz Split Installation Guide
Chapter 4 Troubleshooting
Low or Degraded Forward RF Signal
The forward RF signal can be measured at the –20 dB RF test point on the optical
receiver and the amplifier module forward output test points.
Low or Degraded Forward RF Signal Troubleshooting Table
Before you begin troubleshooting for a low or degraded forward RF signal, verify
that the amplifier is receiving the proper forward RF input signal from the optical
receiver.
Important: You cannot balance the amplifier without the proper forward RF input
Important: You cannot balance the amplifier without the proper forward RF input
signal.
Make sure you have configured the amplifier module according to the specifications
Make sure you have configured the amplifier module according to the specifications
in the design print, and that the amplifier has warmed up for approximately 1 hour.
Make sure you are using the proper tilt reference when setting levels. An 870 MHz
Make sure you are using the proper tilt reference when setting levels. An 870 MHz
or 1 GHz design balanced at 550 MHz requires a corrected tilt reference to
compensate for the difference in carrier levels between 550 MHz and 870 MHz or 1
GHz. The tilt reference at 550 MHz is lower than the tilt reference at 870 MHz or 1
GHz.
Important: If the amplifier cover was ever removed, make sure it was properly
Important: If the amplifier cover was ever removed, make sure it was properly
reinstalled. Improperly reinstalling the amplifier module cover may result in RF
signal degradation.
Possible cause
Solution
There is a proper forward RF
signal at the forward optical
receiver test point, but a low or
degraded signal at one or all of
the forward output test points.
Verify that the amplifier module is receiving
the proper DC voltages. Refer to No DC Power
(on page 69).
Verify that all the proper accessories, pads,
EQs, and signal directors (if applicable) are
firmly installed in the correct locations.
Verify that the factory installed accessories are
firmly installed in the correct locations.
Note: Verifying factory installations involves
Note: Verifying factory installations involves
removing the amplifier module cover. Reinstall
the amplifier module cover properly or RF
signal degradation may result.
Replace the amplifier module.
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