Cisco Cisco 1 GHz GainMaker Amplifier インストールガイド
Chapter 4 Troubleshooting
82
Low or Degraded Forward RF Signal
The forward RF signal can be measured at the amplifier module forward input and at
the Main, Aux 1, and Aux 2 forward output test points.
the Main, Aux 1, and Aux 2 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 upstream
amplifier.
that the amplifier is receiving the proper forward RF input signal from the upstream
amplifier.
Important: You cannot balance the amplifier without the proper forward RF input
signal.
signal.
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 one
hour.
in the design print, and that the amplifier has warmed up for approximately one
hour.
Make sure you are using the proper tilt reference when setting levels. An 870 MHz, 1
GHz or 1.2 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, 1 GHz
or 1.2 GHz. The tilt reference at 550 MHz is lower than the tilt reference at 870 MHz, 1
GHz or 1.2 GHz. Refer to the tilt charts in Technical Information (on page 89) for
more information.
GHz or 1.2 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, 1 GHz
or 1.2 GHz. The tilt reference at 550 MHz is lower than the tilt reference at 870 MHz, 1
GHz or 1.2 GHz. Refer to the tilt charts in Technical Information (on page 89) for
more information.
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.
reinstalled. Improperly reinstalling the amplifier module cover may result in RF
signal degradation.
Possible cause
Solution
Low or degraded forward RF signal
at the forward input test point.
at the forward input test point.
Verify that the amplifier is receiving the proper
forward RF input signal from the upstream
amplifier.
Important: You cannot balance the amplifier
without the proper forward RF input signal.
forward RF input signal from the upstream
amplifier.
Important: You cannot balance the amplifier
without the proper forward RF input signal.