GE MDS Mercury 3650, Справочное руководство

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05-4446A01, Rev. E Mercury Reference Manual 157
4.2 RADIO (RF) MEASUREMENTS
There are several measurements that should be performed during the ini-
tial installation. These measurements confirm proper operation of the
unit and, if they are recorded, serve as a benchmark in troubleshooting
should difficulties appear in the future. These measurements are:
• Transmitter Power Output
• Antenna System SWR (Standing-Wave Ratio)
• Antenna Direction Optimization
These procedures might interrupt traffic through an established network
and should only be performed by a skilled radio-technician in coopera-
tion with the Network Administrator.
4.2.1 Antenna System SWR and Transmitter Power
Output
Introduction
A proper impedance match between the transceiver and the antenna
system is important. It ensures the maximum signal transfer between the
radio and antenna. You can check the impedance match indirectly by
measuring the SWR (standing-wave ratio) of the antenna system. If the
results are normal, record them for comparison during future routine
preventive maintenance. Abnormal readings indicate possible trouble
with the antenna or the transmission line, and should be corrected.
Check the SWR of the antenna system before putting the radio into reg-
ular service. For accurate readings, a wattmeter suited to the frequency
of operation is required. One unit meeting this criteria is the Bird Model
43
™ directional wattmeter with the appropriate element installed.
The reflected power should be less than 10% of the forward power
(
≈ 2:1 SWR). Higher readings indicate problems with the antenna, feed-
line or coaxial connectors.
Record the current transmitter power output level, then set it to an ade-
quate signal level for the directional wattmeter (for the duration of the
test.)
System Bootup (power on) INFORM Self explanatory
Telnet Access Locked for
5 Min MAJOR Self explanatory
Telnet User Logged
Out/Logged In MAJOR Self explanatory
User Selected Reboot MAJOR Self explanatory
Table 4-7. Non-Critical Events—Alphabetical Order (Continued)
Event Log Entry Severity Description