Section-d: dsc & Alpha-Numeric id: Key Topic #27: dsc Operations:

27D1 Which of the following statements concerning DSC equipment is true?

A. The GMDSS Radio Operator is not responsible for properly selecting HF DSC guard channels because they are done automatically by the watch receiver.

B. All equipment must be type accepted by Inmarsat.

C. The vessel's navigational position must be updated, either automatically or manually, no less often than every four (4) hours.

D. The GMDSS Radio Operator is responsible for properly selecting VHF & MF DSC guard channels but the HF frequencies are done automatically by the watch receiver.

27D2 What is the action that a GMDSS Radio Operator should take when a DSC Distress alert is received requesting J3E?

A. No action is necessary, as the DSC control unit will automatically switch to the SITOR (NBDP) follow-on communications frequency.

B. The Operator should immediately set continuous watch on VHF channel 70.

C. The Operator should immediately set continuous watch on the SITOR (NBDP) frequency that is associated with frequency band on which the Distress alert was received.

D. The Operator should immediately set continuous watch on the radiotelephone frequency that is associated with frequency band on which the Distress alert was received.

27D3 What does the DSC control unit do if the GMDSS Radio Operator fails to insert updated information when initiating a DSC Distress alert?

A. It will initiate the DSC Distress alert and default information will automatically be transmitted.

B. It will abort the transmission and set off an audible alarm that must be manually reset.

C. It will initiate the DSC Distress alert but, as no information will be transmitted, rescue personnel will not be able to identify the vessel, its position, or its situation.

D. It will initiate the DSC Distress alert, but any station receiving it will have to establish contact with the distressed vessel to determine its identity, position, and situation.

27D4 A DSC Distress alert:

A. Must always be sent on VHF Ch-70.

B. Will always be sent on one or more of the DSC Distress frequencies.

C. Must always be sent on MF 2 MHz plus one other HF DSC frequency.

D. Must always be sent on VHF Ch-70, then 2 MHz MF then 8 MHz HF.

27D5 In all cases, the transmit frequency of a MF/HF console DSC Distress alert:

A. Will always go out first on 2187.5 kHz.

B. Depends upon operator DSC Call set up entries or manufacturer’s defaults.

C. Will go out on 8 MHz and 2 MHz and one other DSC Distress frequency.

D. Will always go out first on 8414.5 kHz to ensure receipt by a coast station.

27D6 DSC relays of Distress alerts by vessels:

A. Should be done for all Distress alerts received aboard the ship.

B. Should be transmitted to all ships involved in Distress traffic.

C. Should be avoided; unless an acknowledgement has not been heard.

D. Are the best means to provide for a retransmission of Distress communications.

Answers: 27D1 - C 27D2 - D 27D3 - A 27D4 - B 27D5 - B 27D6 - C