Harris Constellation, Руководство по установке и обслуживанию

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Harris Corporation Constellation™
Installation and Commissioning 4-5
INSTALLATION AND
CO
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Monitoring Recommendations
It is important that you use high-quality adapters
when monitoring power output at the radio
monitor port. Inexpensive “screw together”
adapters introduce unpredictable amounts of
signal loss. Attempting to compensate for this
signal loss can result in sync loss and errored
seconds events.
Monitoring the Reference Frequency
Harris recommends monitoring the reference frequency during installation,
and then at least once a year while the radio is in service.
The specification for the oscillator is +/- 300 Hz. The reference oscillator
frequency can be adjusted through the Keypad. If it cannot be adjusted within
300 Hz, the OCXO should be replaced.
Performing routine checks and recording any adjustments can expose a
potential crystal problem before there is a failure. Changes in crystal frequency
are most likely in the first few months of operation. After three to six months,
the crystal should stabilize.
UBER Measurement
UBER (uncorrected bit error ratio) is a measurement that shows BER before
FEC takes place. UBER command can be accessed through the Keypad’s hidden
Measurement submenu.