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VHF DSC radio Jargon buster

The VHF DSC Radio jargon buster

AIS – Automatic Identification System

This system is used by shipping. It allows another vessel or coast station to use equipment that can interrogate the radio in order to learn the course, speed, type of vessel, cargo, etc. It is also available to recreational vessels.

ALRS

Admiralty List of Radio Signals

ATIS

Automatic Transmitter Identification System

Authorised Operator

The person with the VHF Short Range Certificate who also has an Authority to Operate.

Callsign

Unique letter/number vessel identification number

CG66

Coastguard Yacht and Boat Safety Scheme form

Convention ships

Cargo vessels over 300 Gross Registered Tons and passenger ships that carry 13 or more people.

COSPAS/SARSAT

A satellite-aided search and rescue system designed to locate EPIRBS transmitting on 406 MHz.

Distress

A situation when a vessel, vehicle, aircraft or person is in grave and imminent danger and requests immediate assistance.

DSC

Digital Selective Calling

DTI

Department of Trade and Industry

Dual watch

A facility that allows you to monitor CH16 and one other channel at the same time.

Duplex

Radio working that uses two antennas for working on a two frequency VHF channel.

EPIRB

Emergency Position Indicating Radio Beacon

GHz

Gigahertz

GMDSS

Global Maritime Distress and Safety System

GMT

Greenwich Mean Time

GPS

Global Positioning System

HF

High Frequency

IMO

International Maritime Organisation

INMARSAT

International Mobile Satellite Organisation

ITU

International Telecommunication Union

Mayday

Distress signal. Origin French – m’aidez – help me.

MF

Medium Frequency

MHz

Megahertz

MMSI

9-digit Maritime Mobile Service Identity

Navtex

Maritime safety information broadcast received on 518 KHz and 490kHz as text.

NBDP

Narrow Band Direct-Printing, see Navtex

NMEA interface

Marine industry standard method of connecting one piece of electronic equipment to another, eg GPS with autopilot. Pan Pan–Urgency signal. Origin French – en panne – in difficulty.

PTT

Press to transmit switch

Public Correspondence

Telephone communications

Radio Check

Test call that asks ‘What is the strength and clarity of my transmission?’.

Radio horizon

The distance the radio signal will travel before it reaches the horizon.

RX

Receive

SAR

Search and Rescue

Securite

Safety signal. Origin French – sécurité – safety.

Semi-Duplex

Radio working that uses one antenna to switch between two frequencies on one channel. One frequency for transmitting, the other for receiving.

Simplex

Radio working that uses the same frequency for transmitting and receiving.

Squelch

A radio control that suppresses background interference.

Traffic

Radio messages

TX

Transmitting

UHF

Ultra High Frequency (300–3000MHz)

UKCG

UK Coastguard

Urgency

A situation that is not grave and imminent but serious.

UTC

Universal Co-ordinated Time. This is also known as GMT (Greenwich Mean Time). This is the basis for all calculations of time and it is the time shown on the display of a VHF-DSC radio. Times around the world are all related to UTC.

VHF

Very High Frequency

Voluntary Fit

Vessels that are not ‘Convention Ships’ (see Convention Ships).

VTS

Vessel Traffic Services

Watt

A measure of power output

Find out more about VHF DSC radio operation:

VHF DSC radio operation

Reeds VHF DSC Radio App

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