Cable AML ITX02-2000 Operation Installation Maintenance Manual
                          | |
Contents
| 
Indoor Broadband Transmitter – ITX02-20008IM402513-10 Rev –Microwave Low Noise AmplifierA Low Noise Amplifier accomplishes the amplification with minimum distortion.DC Diagnostics CircuitCertain test points in the transmitter can be monitored externally at the Remote Monitor outputmulti-pin connector on the front panel. These DC diagnostics are connected to the outputconnector through a signal conditioning circuit. The signal conditioning circuit is a network ofresistors that provides short circuit protection for the transmitter diagnostic sources. The outputconnector is designed for use with diagnostic test boxes such as the Cable AML DTB - 1, theWRM-2, or the RM-2A. The test points and corresponding connector pin connections are shownin the Transmitter Block Diagram.Power SupplyThe power supply for the MMDS Driver is +12 VDC.2.2 Power Amplifier ChainsThe power amplifier consists of four GaAs FET microwave power amplifier that amplifies theinput signal to a maximum level consistent with the Carrier to Composite Triple Beat (C/CTB)specification. The power amplifier is protected from failure due to overheating by an internaltemperature sensor. The sensor circuit automatically switches off the amplifier input powerwhen the amplifier temperature exceeds 167°F (75°C). The power amplifiers are arranged in aquadruple power configuration which results in an overall IP3 increase of 5 dB. The gain of theamplifiers is 56 dB with an IP3 of 69.5 dBm. The amplifiers have a TTL circuit, which enablesthe user to shut down the amplifiers for testing purposes. +5VDC = “ON”2.3 Power Supply AssemblyThe transmitter has a 12 VDC redundant power supply system consisting of three current-sharing modules with hot-plug replacement capability. Each module has an 84 Amp capability.Only two modules in each mainframe are needed to run the transmitter. A 24 VDC powersupply powers the internal downconverter and also supplies voltage to a 5 VDC voltageregulator, which is used with the Transistor-Transistor-Logic (TTL) of the power amp. Aseparate +12 VDC power supply is used for the Driver.2.4 Diagnostic Circuits1The ITX02-2000 transmitter has several connectors and switches.Connectors - there are "test point" and "monitor" output connectors on the front panel. Theirposition in the circuitry is shown in Figure 3.1See Data Manual for nominal values of diagnostic signals. |
Related manuals for Cable AML ITX02-2000
This manual is suitable for:
manualsdatabase
Your AI-powered manual search engine