Cisco Cisco 1 GHz GainStar Amplifier Installation Guide
4-4 Troubleshooting 4034994 Rev B
Low or Degraded Forward RF Signal
The forward RF signal can be measured at the amplifier module forward input and
at the forward output main1 and forward output main2 test points.
at the forward output main1 and forward output main2 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.
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
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 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 (on page 6-1) for more
information.
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.
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.
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 (on page 6-1) for more
information.
Possible Cause
Solution
Low or degraded forward RF signal at the
forward input test point.
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.
proper forward RF input signal from the
upstream amplifier.
Important: You cannot balance the
amplifier without the proper forward RF
input signal.
There is a proper forward RF signal at the
forward input test point, but a low or
degraded signal at one or all of the
forward output test points.
forward input test point, but a low or
degraded signal at one or all of the
forward output test points.
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.
Replace the RF module
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.
Replace the RF module