Raymarine Ray215 - Manual (Page 10)

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GLOSSARY OF TERMS
All Scan ........................... Scans all channels
Canadian Channels ......... Channel designator as defined by Industry
Canada
Carrier Wave ................... A Radio Frequency on which intelligence is
superimposed.
DSC ................................. Digital Selective Calling
Dual Watch ..................... Monitor the Priority Channel (9 or 16) while
working on another channel
Duplex ............................. Transmit and receive on different frequencies
FCC ................................. Federal Communications Commission
FM .................................. Frequency Modulation
International Channels .... Channel designator as defined by the ITU
ITU .................................. International Telecommunications Union
LCD ................................. Liquid Crystal Display
Memory Scan .................. Scans only user selected memory channels
MMSI .............................. Maritime Mobile Service Identity; a number
issued by each country to identify maritime
stations.
NOAA ............................. National Oceanographic and Atmospheric
Administration
PLL .................................. Phase Locked Loop (a type of frequency
synthesizer)
PTT switch ...................... Microphone push-to-talk switch
RF .................................... Radio Frequency
RTCM .............................. Radio Technical Commission for Maritime
Services
RX ................................... Receiver
Simplex ............................ Transmit and receive on the same frequency
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 ........................ Monitor the Priority Channel and Weather
Channels while working on another channel
US Channels ................... Channel designations as defined by the FCC
VCO ................................. Voltage Controlled Oscillator
VHF ................................. Very High Frequency 30MHz to 300MHz
Weather Channels ........... Channels for routine and emergency weather
information broadcast by NOAA