User Manual Part 2

Lynx.GX Installation and Management
Power Adjustment
If only one end has low RSL, this could be caused by low transmit output power from the opposite end radio.
Verify that the transmitter output power of the radio opposite to the low RSL receiver has been set in
accordance to path calculations or EIRP restrictions (where applicable).
WARNING! Power adjustment must be performed by professional installation personnel only.
Tx Power can be viewed or adjusted from the Sys Cfg web page.
If an RF power meter is available, you can connect it to the RF output of the RF Unit for precision measurement.
This test also verifies that the radio transmitter is working properly. This is highly recommended if RSL is low in
only one direction. If one terminal has high RSL, this could be caused by interference.
Short Path or Interference
To verify the possible presence of interference, remove DC power to the unit opposite the one that is reading
high RSL or experiencing errors. Once power is removed, measure RSL on the remaining radio. If RSL
voltage is lower than its threshold, it is unlikely that an interfering signal is present. If an RSL measurement is
made above threshold, then the presence of interference is likely.
If interference is suspected, the most effective potential remedy is to swap frequency channels on both sides of
the link. (see “Changing Frequency Plans” on page 93). Swap RF Units at both ends of the link so they are the
opposite of their original installation. After both ends are moved, reconnect the radios and determine whether
the BER alarm is still active. If so, you can select other frequency channels or try other interference counter-
measures, as discussed in “Counteracting and Evaluating Interference” on page 93.
Possible Radio Failure
If all path related and data input problems have been pursued and the BER alarm is still active, the problem
could be related to a radio failure. Although radio failure typically is indicated by more severe alarm conditions,
it is possible that one of the radios may be out of specification, and this could be the cause of the BER alarm. A
back-to-back test verifies proper radio operation. See “Test Radios Back-to-Back” on page 11 for more
information. A threshold test on both radios, along with a test to verify proper RF output power, would be
beneficial.
Perform a back-to-back test before returning any radio terminal to the factory for repair. A back-to-back test
verifies radio operation.
If the radios pass their back-to-back testing successfully, the problem is likely with the path, with the connections
between the radio and the antenna, or interference. Before you reinstall the radios, be sure to set the output
power to the appropriate level for the installation.
Appendix G. Troubleshooting 97