ADTRAN 12804108L1A System Manual

ADTRAN 12804108L1A System Manual Manual pdf 59 page image

TRACER 4108/4208 System Manual Section 6 Troubleshooting Guide612804208L1-1B © 2003 ADTRAN, Inc. 59identity potential line-of-site obstacles, properly size antenna dishes, and determine minimumantenna dish heights above the earth.2. Setup all of the TRACER hardware on a workbench. ADTRAN recommends that the actual cablesused 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 thefrequency plan for each TRACER 4108/4208 unit. The frequency plan (Plan A, Plan B) LEDshould be the opposite on the TRACER 4108/4208 units.4. Verify that both ends of the link are configured for the same RF Bandplan (1, 2, or 3). See>TRACER System Options > RF Bandplan on page 48 for more details.5. Verify that both ends of the link are configured for the same number of active T1 ports. See>TRACER System Options >Active T1 Ports on page 49 for more details.6. Attach the RF coaxial cables to be used in the permanent installation to the N-type connectors onthe back of the TRACER 4108/4208 unit. Attach the other end of the coaxial cable(s) to an RFpower meter or spectrum analyzer, if either is available. The power measured by themeter/analyzer will be the RF power available at the input of the antenna. The TRACER4108/4208 unit is programmed at the factory to output approximately 100 mW (20 dBm) of RFpower. The actual power level measured by the meter/analyzer will be less than 100 mW due to RFlosses through the coaxial cable, and is a function of the cable type and length being used. In anyevent, 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 anindication of any combination of either unsuitable RF, or faulty, or unreasonably long coaxialcable.7. Resolve all RF coaxial cabling errors before proceeding.8. Attach the RF coaxial cables to a high-quality attenuator, if possible. If you do not have anattenuator, attach the coaxial cables to the antennas to be used in the permanent installation. If theinstallation antennas are not available, small, inexpensive dipole or patch antennas can be used forverification purposes. If an adjustable attenuator is being used, dial in the amount of attenuationthat corresponds to the path loss value expected for the microwave link in which the TRACERhardware will be installed. The path loss value can be calculated from a knowledge of the pathlength, or provided by a path study. Remember to subtract both antenna gain values from theattenuator level if these values have not already be accounted for.9. After setting up the RF pieces, examine the RF DOWN LED on the front panel of each TRACER4108/4208 unit. If the RF DOWN LED is illuminated (red), the corresponding TRACER4108/4208 is not receiving a suitable RF signal from the other TRACER 4108/4208 unit. In thiscase, the receiving TRACER 4108/4208 is either receiving a very weak signal, or no signal at all.If the RF DOWN LED is not illuminated, then the TRACER 4108/4208 units are receiving aADTRAN provides a wireless link planning tool on our website. This link budget tool isconstructed as an easy to use spreadsheet with dropdown menus so that the user canquickly 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 isaffected. This tool is available at www.adtran.com/wireless and can be used online ordownloaded for standalone use.

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