TRACER 4102/4202 System Manual
Section 6 Troubleshooting Guide
612804202L1-1A
© 2004 ADTRAN, Inc.
59
2. Setup 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 4102/4202 unit. The frequency plan (Plan A, Plan B) LED
should be the opposite on the TRACER 4102/4202 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 48 for more details.
6. Attach the RF coaxial cables to be used in the permanent installation to the N-type connectors on
the back of the TRACER 4102/4202 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 4102/4202 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 either unsuitable RF, or faulty, or unreasonably long coaxial cable.
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 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 be accounted for.
9. After setting up the RF pieces, examine the
RF DOWN
LED on the front panel of each
TRACER 4102/4202 unit. If the
RF DOWN
LED is illuminated (red), the corresponding
TRACER 4102/4202 is not receiving a suitable RF signal from the other TRACER 4102/4202 unit.
In this case, the receiving TRACER 4102/4202 is either receiving a very weak signal, or no signal
at all. If the
RF DOWN
LED is not illuminated, then the TRACER 4102/4202 units are receiving a
suitable RF signal. Suitable RF power levels for low error rate communication will range from
-30 dBm to -100 dBm (TRACER 4102) or -30 dBm to -96 dBm (TRACER 4202) measured at the
N-type connector input on the TRACER 4102/4202 unit.
10. Resolve any signal level issues before proceeding.
11. Examine the
RF LOW
LED on the front panel of each TRACER 4102/4202. If this LED is
illuminated, then the TRACER 4102/4202 is receiving a relatively weak signal; however, if the
RF
DOWN
LED is not illuminated, then the received signal is being suitably processed by the
TRACER 4102/4202 system. If you are receiving a weak signal (
RF LOW
is
ON
), please verify that
the weak signal is not being caused by a faulty cable, an insufficiently tightened cable, or some
other installation-related problem. Also, make sure an unreasonably large attenuation value has not
been selected if you are using an attenuator on a workbench setup.
