UHF-2 Receive

Table 1-3.-UHF-1 and UHF-2 Operating Modes guard receiver is a separate module and is a complete and independent fixed-tuned, crystal-controlled receiver that operates on the guard frequencies. The receiver sections receive command signals from the control box, placing it in the proper condition for the mode selected. All receiver outputs derived from guard, FM, FSK, wide-band, and voice modes are routed through the audio interface, and then switched through the COMM switching matrix to the external equipment. UHF-2 Receive The RF signal received at the UHF tailcap or UHF lower antenna is coupled into the UHF-2 RT through the antenna switching relay, and the UHF filter. From this point on, the operation is the same as in the UHF-1 radio set. Modes of Operation Table 1-3 shows the modes of operation for the two radio sets. HF COMMUNICATIONS Learning Objective: Recognize components and operating principles of the HF radio system. The AN/ARC-161 HF radio system provides two-way communications between the aircraft and any similarly equipped platform. It provides transmission, reception, and processing of intelligence and tactical data. The cipher voice communication is provided by the TSEC/KY-75 high-frequency security unit. 1-16