Cisco Cisco 870 MHz GainMaker Amplifiers Installation Guide
Chapter 4 Troubleshooting
94
Possible cause
Solution
There are proper reverse RF signals
at the reverse input test point, but a
low or degraded signal at the reverse
output test point.
at the reverse input test point, but a
low or degraded signal at the reverse
output test point.
Verify that the line extender module is
receiving the proper DC voltages. Refer to No
DC Power (on page 87).
receiving the proper DC voltages. Refer to No
DC Power (on page 87).
Measure the main reverse input test point and
the reverse output test point. Subtract the
reverse amplifier gain and add the pad values
and EQ insertion loss to verify proper reverse
amplifier gain.
the reverse output test point. Subtract the
reverse amplifier gain and add the pad values
and EQ insertion loss to verify proper reverse
amplifier gain.
Verify that all the proper accessories, pads,
EQs, and signal directors (if applicable) are
firmly installed in the correct locations.
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.
firmly installed in the correct locations.
Verify that the reverse switch and its jumpers
are properly and firmly installed.
Note: Verifying factory installations involves
removing the line extender module cover.
Reinstall the line extender module cover
properly or RF signal degradation may result.
are properly and firmly installed.
Note: Verifying factory installations involves
removing the line extender module cover.
Reinstall the line extender module cover
properly or RF signal degradation may result.
Reverse RF signal still low or
degraded.
degraded.
Use a spectrum analyzer to look at the reverse
RF input signal spectral quality at each reverse
input test point and compare it to the reverse
RF output signal spectral quality.
–
RF input signal spectral quality at each reverse
input test point and compare it to the reverse
RF output signal spectral quality.
–
If degradation is generated in the reverse
amplifier, replace the reverse amplifier.
amplifier, replace the reverse amplifier.
–
If degradation is generated by the
downstream line extender reverse RF
signal, troubleshoot the line extender
feeding this station.
downstream line extender reverse RF
signal, troubleshoot the line extender
feeding this station.
Replace the line extender module.