Tổng quan hệ thống GMDSS phục vụ TKCN. Năm 1979,Tổ chức Hàng Hải quốc tế (International Maritime Organization IMO) đã tổ chức hội nghị về vấn đề tìm kiếm và cứu nạn trên biển. ... Hệ thống mới được tự động hóa và sử dụng sóng vô tuyến trái đất và vệ tinh cho báo động cấp cứu và các thông tin theo sa
Trang 1Cau hoi Simplex operation is where one frequency is used for
A a paired frequency ITU Channel
B alternate transmission and reception
C the up and down link on an Inmarsat phasing signal
D DSC Routine and Distress Alerts
Cau hoi GMDSS Sea Area A3 is best described as being an area within
A continuous global coverage of the COSPAS-SARSAT system
B MF RT range of at least one shore station providing continuous MF DSC alerting
C 70º - 90º North and 70º - 90º South
Cau hoi The control which automatically adjusts the Radio Frequency amplification is known as
an
Cau hoi The emission or mode control of an MF/HF transceiver
A increases the range of the transmitter
B reduces the received gain automatically
C allows the type of modulation to be selected
D allows fine tuning of the receiver
Cau hoi On an MF transceiver, DUPLEX operation is the use of one
A control to change RF gain and another control to the AF gain
B handset for MF RT and another handset for HF RT
C frequency to transmit and another frequency to receive simultaneously
D battery bank to power the transmitter and another battery bank for the receiver
Cau hoi The correct mode of emission for a RT distress message on 2182 kHz is
Cau hoi GMDSS Sea Area Al is best described as being an area within
A approximately 100 to 150 miles from the coast
B range of the Inmarsat system
C VHF RT range of at least one shore station providing continuous VHF DSC alerting
D MF RT range of at least one shore station providing continuous MF DSC alerting
Cau hoi On a transceiver, SIMPLEX operation is the
A alternate use of one frequency to transmit or receive
B use of one control for AF and RF Gain
Trang 2C use of one frequency to transmit and a second frequency to receive
D type of modulation used on 2182KHz
Cau hoi On VHF the transmitted power should be reduced to
D Increase the volume of the received signal
Cau hoi A set of ITU RT paired frequencies can be described as
Cau hoi The mode of emission used for voice on MF and HF is
Cau hoi A common abbreviation for the mode of emission for a RT distress message on 2182
kHz is
Cau hoi On a transceiver, DUPLEX operation is the use of one
A control for AF gain and RF gain
B antenna to transmit and receive
C frequency to transmit and a second frequency to receive
D frequency to transmit and receive
Cau hoi The emission or mode used for RT (voice) operation on MF is
Cau hoi The correct mode of emission for HF radiotelephony SSB transmission is
Trang 3Cau hoi On MF and HF transmitters the emission or mode control
A controls the selection of the ITU Channel
C selects the type of modulation
D adjusts the power output
Cau hoi One of the advantages of using J3E is
A the signal is less efficient than R3E
B the received signal is clearer than H3E
C less current is drawn from the batteries than H3E
D the signal contains less power than H3E
Cau hoi The correct mode of emission for a MF Radiotelex transmission is
Cau hoi Ship to ship Safety of Navigation RT communication on Ch.13 VHF uses a
Cau hoi An Automatic Gain Control adjusts the
B radio frequency (RF) gain
C fine tuning of the received frequency
D audio frequency (AF) gain
Cau hoi Using high or maximum power on an MF transmitter would give a typical range of
Cau hoi The maximum output power of marine VHF is limited to