In SEA AREA A1, which VHF DSC frequency is designated for the audible alarm mode?

In SEA AREA A1, which VHF DSC frequency is designated for the audible alarm mode?

• A. 156.8 MHz
• B. 156.525 MHz
• C. 2187.5 kHz
• D. 2182 kHz

Answer: (A)

Audible alarm on VHF DSC is tied to the channel that instantly grabs attention for distress calls—the voice distress channel. That channel is 156.8 MHz, known as Channel 16. It’s the primary safety channel used for immediate voice communication and alerts, so when a DSC distress message is received, the radio can trigger an audible alarm on this channel to ensure the operator notices right away. The other options aren’t it for VHF audible alarm: 156.525 MHz is the DSC calling/digital distress frequency on Channel 70, used to initiate DSC distress or safety communications, not to trigger the audible alarm. The two MF frequencies, 2187.5 kHz and 2182 kHz, belong to the MF band and aren’t used for VHF audible alarms.

Audible alarm on VHF DSC is tied to the channel that instantly grabs attention for distress calls—the voice distress channel. That channel is 156.8 MHz, known as Channel 16. It’s the primary safety channel used for immediate voice communication and alerts, so when a DSC distress message is received, the radio can trigger an audible alarm on this channel to ensure the operator notices right away.

The other options aren’t it for VHF audible alarm: 156.525 MHz is the DSC calling/digital distress frequency on Channel 70, used to initiate DSC distress or safety communications, not to trigger the audible alarm. The two MF frequencies, 2187.5 kHz and 2182 kHz, belong to the MF band and aren’t used for VHF audible alarms.