User Manual

Exalt Communications, Inc.
Exalt i-Series Installation and Management Guide
5000001 106
2007-06-25
Use the volt meter to measure RSL in both directions. The RSL measured value should
match the appropriate value according to the inserted attenuation, such as:
RSL = RF Output Power – cabling losses – total attenuation
Verify output power by adjusting output power using the Exalt GUI (in administration
mode) and evaluate the corresponding change to the RSL measurement.
For threshold testing, the key is to insert a measured amount of loss that is close to, but
not exceeding the radio’s specified system gain. System gain is the difference between
RF output power and receiver threshold. At your selected modulation and bandwidth
settings, determine the specified threshold performance, and choose a value of
attenuation (including cable losses) that adds to roughly 5 to 15dB less than the system
gain.
For example, for the EX-2.4i, if the threshold for your measurement is -85dBm, the
output power is +27dBm, so the system gain is 112dB. Choose a value of total
attenuation in the range of roughly 100–105dB. Once this attenuation is inserted, verify
RSL readings as in the first step, and then, using the GUI, reduce radio output power in
1dB steps until the receiving radio (the one whose output power not being adjusted) Link
LED turns from green to yellow. This indicates that threshold has been reached. At this
point, verify the equation for system gain using the new output power level setting and
verify that the threshold performance is meeting or exceeding the published specification.
Note: Due to the variation of measurements and accuracies involved
in this test, you may read a measurement that is 1dB to as much as 2dB off
of the expected value. It should be of no concern unless the value is more
than 3dB worse than expected.
Once threshold is verified in this direction, repeat the process in the opposite direction by
adjusting RF output power of the radio at the opposite end. Return the first radio to its
original power setting before adjusting the second radio.
Perform threshold measurement tests for all combinations of bandwidth and mode
(modulation) being used–especially when troubleshooting. It should not be necessary to
vary center frequency, as this does not have any appreciable impact on system gain
performance, however, try any setting combination to gain confidence in the radio
performance parameters.