Cable AML ITX21-100, Руководство по установке и обслуживанию

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Indoor Broadband Transmitter – ITX21-100
IM4030013-1 Rev –
17
Power Amplifiers not Warm
If the amplifier fins are cool, then check for AC at the input to the amplifier power supply. If
AC is present at the input to the power supply and the amplifier is cool then replace the
amplifier.
Power Supplies O.K. and Power Amplifier Warm, but Low or No Output
Check all internal RF connections. For the SMA connectors, a 5/16" open-end wrench is
required. "Finger-tight" is not acceptable for microwave connections.
Check the power level at the DRO test point. If the level is 3 dB or more below the value
specified in the test data sheet (nom5 dBm) then the DRO is defective and should
be replaced.
Source Power and Upconverter LO Power O.K.
Reconnect all lines. Disconnect the output line at the upconverter and measure its output
at microwave. If no or low output is observed, the upconverter is defective.
Upconverter Output O.K.
Check the output at the filter assembly feeding the power amplifier. This should be 1 to 2
dB lower than measured out of the upconverter. If there is no output at this point, the VHF
input or pump frequencies are wrong.
Filter Assembly Output O.K.
Remove the SMA coaxial cable on the 40 dB directional coupler at the output of the power
amplifier. Measure the microwave power at the coupler output. It should be about 10 dB
above the power measured at the upconverter or filter assembly output. If not, the
amplifier is defective. Replace the power amplifier and its power supply.