What frequency is associated with the fixed-tune guard receiver?

• A. 243.000 MHz
• B. 121.500 MHz
• C. 300.000 MHz
• D. 137.000 MHz

Answer: (A)

A guard receiver is a dedicated radio that stays tuned to a distress/emergency frequency so it can hear calls without any manual tuning. The fixed-tune guard receiver is set to a specific channel, chosen so you can respond immediately when a distress transmission comes in.

For this equipment, that fixed-tune guard frequency is 243.000 MHz, the UHF emergency/distress channel used by military aviation. This makes it reliable for rapid coordination with rescue or military assets. The civilian guard frequency on 121.500 MHz exists, but it’s a different, VHF channel and not the one a fixed-tune guard receiver is set to in this context. The other options aren’t standard guard frequencies.