ad & Modulator Amplifier Wattmeter Ref CLK Remote Control A Remote Control B 10/100BT Fast Ethernet 10/100BT Fast Ethernet FIGURE 7-3 Digital Television Transmitter Functional Block Diagram Desired Physical Characteristics Modular Configuration-Each transmitter shall consist of discrete modules. Each module will be installed in one or more appropriate cabinets, wired, and tested in the manufacturer's plant to minimize assembly at the transmitter site. All transmitter wiring shall be clearly labeled at each termination. The transmitter is expected to include the following or similar modules: System Monitoring and Control Local and Remote Control via IEEE 802.3 Local Area Network interface Uninterruptible Power Supply providing continuous power to the transmitter Local and remote control sub-system. The PRACTICAL IP AND TELECOM FOR BROADCAST ENGINEERING AND OPERATIONS transmitter control sub-system will provide complete control and diagnostic information to the LAN interface during absence of power input. Exciter and 8VSB modulation Intermediate Power Amplifier (if required) High power amplifier as required to produce licensed transmit- ter power output RF Switching, filtering, impedance matching, reject, and test loads High voltage beam supply Calibrated RF power measurement system Heat exchanger with redundant coolant pumps and multiple fans for each HPA A chain hoist with adequate capacity to change power amplifier tubes Interlock system meeting the requirements of IEC-215 Transmitters using liquid cooling will include the following major components: Outside heat exchanger, with multiple direct-drive fans Redundant coolant pumps with local and remote switching of pumps Coolant storage tank with level gauge Particle filter Pressure gauges Temperature and flow sensors Test and reject load cooling Interlocks for test and reject load, amplifier flow, and reservoir levels High Power Amplifier Sub-System The IOT and associated magnet and RF circuit assemblies shall be removable from the front of the transmitter incorp