User Manual Part 2

Lynx.GX Installation and Management
Recommended Actions
▪ Check and Verify data interface wiring
▪ Follow the troubleshooting instructions described in “IDU Fail Alarms.”
RF Link Alarms
This LED indicates that the demodulator function is not synchronizing with the intended received signal.
Possible Causes
▪ Severe path fading due to atmospheric conditions, usually accompanied by a low RSL voltage reading
▪ Poor transmission line connections, usually, but not always, accompanied by low RSL voltage reading
▪ Antenna problems, misalignment, or path clearance, usually accompanied by low RSL voltage reading
▪ Improper radio settings (such as frequency channel)
▪ Received signal level (RSL) is too strong
▪ Interference
▪ Far-end radio transmitter circuitry is faulty
▪ Near-end radio receiver circuitry is faulty
▪ Link security ID mismatch between the radios (flashing)
Recommended Actions
Check the following at each end of the link:
▪ Verify that radios are opposite channel plans on each end (for example, one is A1 and other is A2).
▪ Verify that all connections between radios and antennas are secure and all devices between radios and
antennas are rated for the radio frequency band (5.8 GHz). View RF Link alarm while flexing transmission
lines near all connectors to test for poor connector terminations.
Measure RSL by placing a voltmeter across RSL and GND test points and:
▪ Comparing this to the RSL that was expected using path calculations (see “Calculating RSL and Link
Budget” on page 51) and the RSL that was achieved during installation (if RSL was once sufficient).
▪ Pressing and holding the DISPLAY FAR END button and measuring the far-end RSL (while continuing to
hold the button).
▪ Comparing this RSL to the expected RSL from the link budget calculations.
Excessive Loss
If RSL from both ends of the radio are approximately the same as each other, but lower than anticipated for this
installation, then the likely cause of the BER alarm is excessive losses between the radios. Excessive loss
problems could include the transmission line at either end, all adapters, connectors, the antennas, the antenna
alignment, as well as the path itself (any obstructions or clearance problems).
Verify antenna alignment, line-of-sight, and path clearance; if this does not improve RSL, check all devices
between the radios and their antennas at both ends. Make sure all transmission lines, connectors, and any
other devices are properly rated for operation at the radio's frequency (5.8 GHz).
Appendix G. Troubleshooting 96