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Ray49 Marine VHF Radio
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 or 9
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
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 Channel, and one other channel that you choose.
USA Channels
Channel designations as defined by the FCC
VOL
Volume key
VHF
Very High Frequency (30MHz to 300MHz)
Weather (WX)
Channels
Channels for routine and emergency weather information
broadcast by NOAA (USA)
WX
Weather Band key
Working Channel
The currently-selected (non-priority, non-WX) channel
Term
Meaning
