ADTRAN TRACER 5045 - Manual (Page 54)

Section 6 Troubleshooting Guide TRACER 5045 System Manual
54 © 2004 ADTRAN, Inc. 612805045L1-1B
4. STEP-BY-STEP TROUBLESHOOTING
The logical troubleshooting flow presented in this section can be used to set up your TRACER 5045
system, and also to diagnose a previously installed system. Please contact ADTRAN Technical support at
any stage during installation and/or troubleshooting if you require assistance.
5. INSTALLING/TROUBLESHOOTING THE TRACER HARDWARE
1. Perform a detailed path profile and link budget for each TRACER 5045 microwave link. A
thorough path study can be used to estimate signal power budgets, fade margins at each receiver,
identity potential line-of-site obstacles, properly size antenna dishes, and determine minimum
antenna dish heights above the earth.
2. Set up all of the TRACER hardware on a workbench. ADTRAN recommends that the actual
cables used in the permanent installation be used in the workbench setup. A rigorous workbench
“simulation” of the link will help alleviate and avoid time-consuming errors.
3. Examine the PLAN A and PLAN B LEDs on the front panel of each unit. These LEDs indicate the
frequency plan for each TRACER 5045 unit. The frequency plan (Plan A, Plan B) LED should be
the opposite on the TRACER 5045 units.
4. Attach the RF coaxial cables to be used in the permanent installation to the N-type connectors on
the back of the TRACER 5045 unit. Attach the other end of the coaxial cable(s) to an RF power
meter or spectrum analyzer, if either is available. The power measured by the meter/analyzer will
be the RF power available at the input of the antenna. The TRACER 5045 unit is programmed at
the factory to output approximately 100 mW (20 dBm) of RF power. The actual power level
measured by the meter/analyzer will be less than 100 mW due to RF losses through the coaxial
cable, and is a function of the cable type and length being used. In any event, the power level at the
output of the coaxial cable should be a significant fraction of 100 mW. A power meter/analyzer
reading that is not on the order of at least tens-of-milliwatts could be an indication of any
combination of unsuitable RF cable or faulty or unreasonably long coaxial cable.
5. Resolve all RF coaxial cabling errors before proceeding.
6. Attach the RF coaxial cables to a high-quality attenuator, if possible. If you do not have an
attenuator, attach the coaxial cables to the antennas to be used in the permanent installation. If the
installation antennas are not available, small, inexpensive dipole or patch antennas can be used for
verification purposes. If an adjustable attenuator is being used, dial in the amount of attenuation
that corresponds to the path loss value expected for the microwave link in which the TRACER
hardware will be installed. The path loss value can be calculated from a knowledge of the path
length, or provided by a path study. Remember to subtract both antenna gain values from the
attenuator level if these values have not already been accounted for.
7. After setting up the RF pieces, examine the RF DOWN LED on the front panel of each
TRACER 5045 unit. If the RF DOWN LED is illuminated (red), the corresponding TRACER 5045
is not receiving a suitable RF signal from the other TRACER 5045 unit. In this case, the receiving
TRACER 5045 is either receiving a very weak signal, or no signal at all. If the
RF DOWN LED is
ADTRAN provides a wireless link planning tool on our website. This link budget tool is
constructed as an easy to use spreadsheet with dropdown menus so that the user can
quickly change any of the link parameters (antenna size, coaxial cable type and length,
frequency band, link distance, etc.) and instantly see how the microwave path availability
is affected. This tool is available at
www.adtran.com/wireless and can be used online or
downloaded for standalone use.