Installation Manual Part 6

FCC 10: CDG-ARTU EXHIBIT C
MAGNASTAR C-2000 DIGITAL AIRBORNE TELEPHONE SYSTEM
9.1.6 ARTU TRANSMITTER OUTPUT POWER
During the ARTU Transmitter Output Power test, the ARTU will transmit a CW signal at a frequency of
894.9495 MHz. The power level transmitted by the ARTU will be 10 watts minimum. Measurement of
the transmitted signal should be made as close to the Antenna as possible to check the functionality of the
greatest number of the C-2000 components. The insertion loss of components in addition to the ARTU
must be accounted for when measuring the output power of the C-2000 system. The maximum total cable
loss that can be used with the C-2000 system is specified at 3 dB. The maximum specified insertion loss of
the Duplexer is 1.4 dB. If power is measured at the Antenna connector, the minimum power measured
should be no less than 4 watts.
It should be noted that the power meter or thru-line wattmeter used for this test must be capable of
withstanding 16 Watts of RF energy and must be capable of operating at frequency of I Ohz for correct
results.
Symptom: The MMTI appears stuck.
Wait for the MMTI to properly execute commands to ARTU (5-10 sec). Commands to the ARTU
via the MMTI may take from 5 to 10 seconds to execute during which time the MMTI screens will
appear to change and then stop before completing.
Symptom: Low output power / No output power.
If power measurements at the Antenna connector are low, it will be necessary to determine which
component is responsible for the excessive loss by process of elimination. First, measure the
output power directly out of the ARTU. If the power measurement is incorrect replace the ARTU.
If the power measurement is correct, measure the output at the end of the transmit cable. If the
power measurements is incorrect, replace the transmit cable. If the power measurement is correct,
measure the power at the Antenna output of the Duplexer. If the power measurement is incorrect,
replace the Duplexer.
V.. OA MMT Radio Respons '
'ing teat FAN CONTROL perfo~d.
:::::::::: ~ - ~- ~~;w::::7J;~~
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This t..t step is inatructional only.
During the next test step the ARTU will transmit a CW signal at a power
level of +40 to +42 dBm. The Duplexer is specified for a n8Xi.u. loss
of 1.4 dB. The 8aXimu8 syat.. C8ble loas for the RP cables is specified
at 3 dB. The ~r _ter should measure greater than +36 dBm when all
the above factors are taken into account.
[aleturn
Figure 9.1.6.A. ARTU Transmitter Output Power MMTI Troubleshoot Screen.
,,"1 RevS