On what frequencies does the PLB broadcast?

On what frequencies does the PLB broadcast?

• A. 406 MHz and 121.5 MHz
• B. 406 MHz and 243 MHz
• C. 121.5 MHz only
• D. 2.4 GHz

Answer: (A)

Beacons used for locating someone in distress broadcast on two frequencies to cover both satellite alerting and on‑scene guidance. The 406 MHz signal is the primary satellite distress channel; it’s monitored worldwide and carries a digital identifier that helps rescue authorities know who you are and, if your beacon has GPS, where you are. The 121.5 MHz frequency is used as a homing beacon so rescuers in the vicinity can home in on your exact location once the alert has been received. That’s why the other options don’t fit: 243 MHz is a military emergency frequency, not the civilian PLB standard; 2.4 GHz isn’t used for emergency beacons; and 121.5 MHz alone wouldn’t initiate the satellite alert that gets rescuers involved in the first place.

Beacons used for locating someone in distress broadcast on two frequencies to cover both satellite alerting and on‑scene guidance. The 406 MHz signal is the primary satellite distress channel; it’s monitored worldwide and carries a digital identifier that helps rescue authorities know who you are and, if your beacon has GPS, where you are. The 121.5 MHz frequency is used as a homing beacon so rescuers in the vicinity can home in on your exact location once the alert has been received.

That’s why the other options don’t fit: 243 MHz is a military emergency frequency, not the civilian PLB standard; 2.4 GHz isn’t used for emergency beacons; and 121.5 MHz alone wouldn’t initiate the satellite alert that gets rescuers involved in the first place.