Cisco Cisco 862 MHz GainStar Amplifier Guía De Instalación
Chapter 4 Troubleshooting
Low or Degraded Forward RF Signal
The forward RF signal can be measured at the GainStar Line Extender module
forward input and forward output main test point.
Low or Degraded Forward RF Signal Troubleshooting Table
Before you begin troubleshooting for a low or degraded forward RF signal, verify
that the GainStar Line Extender is receiving the proper forward RF input signal from
the upstream amplifier.
Important: You cannot balance the GainStar Line Extender without the proper forward
RF input signal.
Make sure you have configured the GainStar Line Extender module according to the
Make sure you have configured the GainStar Line Extender module according to the
specifications in the design print, and the GainStar Line Extender has warmed up for
approximately one hour.
Make sure you are using the proper tilt reference when setting levels. An 862 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 862 MHz or 1
GHz. The tilt reference at 550 MHz is lower than the tilt reference at 862 MHz or 1
GHz. Refer to the tilt charts in Technical Information for more information.
Possible Cause
Solution
The forward RF signal is weak or degraded
at the forward input test point.
Verify that the line extender is receiving the
proper forward RF input signal from the
upstream amplifier.
Important: You cannot balance the line
Important: You cannot balance the line
extender without the proper forward RF
input signal.
The forward RF signal is normal at the
forward input test point, but it is weak or
degraded at the forward output test point.
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
Verify that the factory installed accessories
are firmly installed in the correct locations.
Replace the RF mainboard.
Replace the RF mainboard.
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