Operation Manual

124 Ray218E and Ray55E Marine VHF Radios
ITU International Telecommunications Union (EU)
MMSI Maritime Mobile Service Identity; a number issued by each
country to identify maritime stations, much like a telephone
number.
NOAA National Oceanographic and Atmospheric Administration (US)
Position Request A DSC call requesting GPS position information from any
station for which an MMSI number is known. You can also send
out your position to other stations.
Priority Channel Channel 16
Priority Scan A feature that alternates monitoring the Priority Channel 16
with each of the regular channels.
PTT switch Microphone push-to-talk switch
RF Radio Frequency
RTCM Radio Technical Commission for Maritime Services
RX Receive
SAR Search And Rescue
Saved Scan Scans only user-selected memory channels
Semi-duplex Channels using separate frequencies to transmit and receive.
Simplex Channels transmitting and receiving on the same frequency.
SOG Speed Over Ground
Squelch A circuit that sets the threshold for cutting off the receiver when
the signal is too weak for reception of anything but noise.
TX Transmit
Tri Watch A function that monitors the Priority Channel (16), the Second-
ary Priority (PLUS) Channel, and one other channel that you
choose.
US Channels Channel designations as defined by the FCC
VOL Volume key
VHF Very High Frequency (30MHz to 300MHz)
Working Channel The currently-selected (non-priority, non-WX) channel
Term Meaning