This is a type of DSC Alert and not a category, but it is often found on many VHF radios as a specific type of Routine Alert. A Group alert is the Routine Alert sent to an MMSI Group (MMSI begins with "0").

For example, a company representative from whom we rented the vessel for the flotilla cruise that we are on, may contact all vessels in the flotilla.

After broadcasting the Group Alert on VHF CH 70, voice communication continues on the selected working channel.

Practise on the VHF radio simulator

The following indicates the procedure for broadcasting a Group Alert to the same MMSI Group as our VHF radio belongs to on VHF CH 70 using the VHF DSC controller:
  1. Select the working channel in Radio mode
  2. Switch to DSC mode
  3. Press the Call softkey
  4. Press the Type softkey three times to scroll through different types of calls to the Group Call
  5. You can change the channel to be used in voice communication (by default, it is the same as the working channel) either
    • From pre-programmed VHF CH 06, 08, 72 and 77 - press the Chan softkey to scroll through them and press the E key, or
    • Manually enter the channel number - use the keypad to type in the channel number and press the E key
  6. Press the Send softkey
  7. Press the E key

The setting up and broadcasting of a Group Alert on VHF CH 70

A Group Alert is transmitted to an MMSI Group on VHF CH 70. Follow with voice communication on the selected working channel.

Reception of a Group Alert

After the reception of a Group Alert on VHF CH 70 the radio will automatically re-tune to the working channel. Then a voice message on the working channel should be listened to and voice communication should follow.

Practice on VHF radio simulator

After the reception of a Group Alert you can:
  • Accept the call: Press the softkey OK.
  • Not accept the call: Press the key C to cancel the ringing and to clear the display. Press the softkey Stop to cancel the ringing only.

Reception of a Group Alert
Last modified: Saturday, 25 April 2020, 7:50 PM