Which frequency is designated as the UHF Guard frequency that the UHF transceiver monitors?

• A. 121.5 MHz
• B. 243.0 MHz
• C. 137.0 MHz
• D. 255.0 MHz

Answer: (B)

Guard frequencies are dedicated channels that stay monitored for emergencies. In the UHF range used for military and aviation communications, the standard guard frequency is 243.0 MHz, so the UHF transceiver is set to that channel to receive distress or priority calls even when other work is ongoing. The other options aren’t the UHF guard channel: 121.5 MHz is the VHF emergency frequency, while 137.0 MHz and 255.0 MHz are not designated UHF guard frequencies.