Guide to Acronyms and Abbreviations used in RadioUser

Guide to Acronyms and Abbreviations used in RadioUser

µF    microfarad
µH    microhenry (see: henry) 
2D/ 3D    two-dimensional/ three-dimensional
4G/ 5G etc.    fourth/ fifth generation of cell phone technology
73    end of transmission (best regards, wish you well, so long, adios, good-bye) 

A    ampère (SI unit of electric current)
AAC    advanced audio coding (e.g.: DAB)
A/D    analogue-to-digital
A17    HFCC summer 2017 operational period
AA    a battery type/ Automobile Association  
AAC    Army Air Corps
AADT    Automatic Adaptive Digital Tracking
AAIU    air accident investigation unit
AARDDVARK    Antarctic-Arctic Radiation Belt Dynamic Deposition VLF Atmospheric Research Konsortia
AATF    air assault task force
ABC    Australian Broadcasting Corporation (see: APTN)
ABP    Associated British Ports
ABS    Acrylonitrile Butadiene Styrene (a polymer used for enclosures) 
AC    alternating current
ACARS    aircraft communications addressing and reporting system
ACAS    airborne collision avoidance system
ACC    Air Control Centre
A-CJEF     airborne combined joint expeditionary force (military)
ADC    analogue-to-digital converter
ADF    automatic direction finder/ finding 
ADIF    amateur data interchange format
ADPCM    adaptive-differential pulse code modulation (DAS, see also: PCM)
ADS    automatic dependent surveillance
ADS-B     automatic dependent surveillance – broadcast
ADS-R    automatic dependent surveillance – re-transmission
ADT    Air Departure Tax
AF    audio frequency
AF    audio frequency
AFB    Air Force Base
AFH    adaptive frequency hopping (e.g. in Bluetooth technology)
AFISO    aerodrome flight information service officer
AFSK    audio frequency shift keying
AFTN    aeronautical fixed telecommunications network
AGC    automatic gain control
AGL    above ground level
Ah    ampères per hour (battery life)
AI    artificial intelligence 
AI    Artificial intelligence 
AIB    Association of International Broadcasters
AIC    aeronautical information circular
AIDU    Aeronautical Information Documents Unit
AIP    Aeronautical Information Publication
AIR    All India Radio
AIR    All India Radio
AIRAC    Aeronautical Information Regulation and Control
AIS     automatic identification system (maritime safety) 
AIS    Aeronautical Information Service (air)
AIS    automatic identification system (marine)
AM    amplitude modulation
AMBE    advanced multi-band excitation
AMDAR    aircraft meteorological data relay
AMSA    Australian Maritime Safety Authority
AMSAT-UK    Radio Amateur Satellites    
AMSE    Ample Strike
AMSL    above mean sea level (altitude) 
AMTOR    amateur teleprinting over radio
ANSP    air navigation service provider
ANSP    air navigation service providers
AOD    above ordnance datum 
AOG    aircraft on ground 
AOS    acquisition of signal (see also: LOS) 
APCO    Association of Public-Safety Communications Officials
API    application program interface
app    application (smartphone or computer) 
APRS    automatic packet reporting system
APT    automatic picture transmission
APTN    Asia-Pacific Technology Network (TV)
AR    augmented-reality
ARC    amateur radio club
ARCC    aeronautical rescue and coordination centre
ARD    Arbeitsgemeinschaft der Rundfunkanstalten Deutschlands (First German TV Chain) 
ARDF    amateur radio direction finding
AREN    amateur radio emergency network (Republic of Ireland) 
ARISS    Amateur Radio on the International Space Station
ARM    Advanced RISC Machine (Code) (e.g.: ARM-32)
ARRC    Allied Rapid Reaction Corps
ARS    amateur radio society
ASACS    Air Surveillance and Control Systems Force Command
ASC    automatic squelch control
ASCII    American Standard Code for Information Interchange
ASL    above sea level
ASQ    automatic squelch
ASR    altimeter setting region
ASRS    Aviation Safety Reporting System (NASA)
ATACMS    army tactical missile system
ATC    air traffic control
ATCC    air traffic control centre
ATI    antenna tuning inductor
ATIS    automatic terminal information service
ATM    air traffic management
ATU    antenna tuning unit
ATV    Associated Television
ATZ    aerodrome traffic zone
Auto-ACAS    automatic air collision avoidance system
AutoCAD    commercial software for 2D and 3D computer aided design and drafting
Auto-GCAS    automatic ground collision avoidance system 
Auto-ICAS    automatic integrated collision avoidance system
aux    auxiliary
AWACS    airborne warning and control system
AWGN    a channel model
AWGN    a channel model
AWN    airborne wireless network
AWR    Adventist World Radio
AZ/EL    azimuth/elevation (antenna rotators)

B17    HFCC winter 2017 operational period
BA    British Airways
BAC    British Aircraft Corporation
BADARS     Braintree and District Amateur Radio Society
Bae    British Aerospace 
BALPA    British Airline Pilots Association 
BALTOPS    Baltic Operations
balun    balanced to unbalanced
BAME    Black, Asian and Minority Ethnic (e.g. communities)
BATC    British Amateur Television Club
BAQ    basic audio quality (e.g. in DAB radio)
BBC    British Broadcasting Corporation
BBMF    Battle of Britain Memorial Flight
BC    British Columbia (Canada)
BCH    Bose, Chaudhuri, and Hocquenghem
BCOMS    Black Community in Media and Sport 
Bd    Baud 
BDF    Brighton Digital Festival
BDXC    Benelux DX Club
BDXC-UK     British DX Club
BEM    British Empire Medal
BFBS    British Forces Broadcasting Services
BFI    British Film Institute
BFM    broadcast FM
BINA    En route Supplement British Isles and North Atlantic (aeronautical information)
bmp (.bmp)    bitmap (file name extension for digital picture format)
BNC    Bayonet Neill-Concelman (coaxial connector)
BNR     Bulgarian National Radio
BNS    Belgian Navy Ship
BOAC    British Overseas Airways Corporation
BPF    band pass filter
bps    bits per second
BPSK    binary phase shift keying
BPSK/ bPSK    binary phase-shift keying (binary PSK)
BR    Bayerischer Rundfunk (Bavarian Broadcasting Corporation) Germany
BRARS    British Railways Amateur Radio Society
BRATS    Bredhurst Receiving and Transmitting Society
BRC    British Radio Corporation (early TV company)
BSKSA    Broadcasting Services of the Kingdom of Saudi Arabia
BST    British Summer Time
BVWS    British Vintage Wireless Society

C    Celsius (SI derived unit for temperature)
C2    command and control
C2D2E    command and control in a denied or degraded environment 
CAA    Civil Aviation Authority
CAI    common air interface
CAMD    Combined Arms Manoeuvre Demonstration
CAOC    Combined Air Operations Centre 
CARP    Channel Availability and Receipt Broadcast (Stanag 4285)
CAS    close air support 
CAT    computer aided transceiver (control/ interface) 
CAT5/ 6    Category 5/ 6 (Ethernet cable)
CATCS    Central Air Traffic Control School
CATOBAR    catapult-assisted take-off barrier arrested recovery
CB    Citizens’ Band
CBC    Canadian Broadcasting Corporation
CBN    Central Brasileira de Notícias
CCIR    International Consultative Committee on Radio
CCTV    China Central Television
CCTV    closed-circuit television
CD/ CD-ROM    compact disc/ compact disc read-only memory
CDS    containerised delivery system
CE    Conformité Européene (from: European Conformity Agreement)
CEO    chief executive officer
CEPT    European Conference of Postal and Telecommunications Administrations
CET    Central European Time
CGC    complementary ground component
CGOC    Coast Guard Operation Centre (UK)
CH, Ch    Channel
CIF    common interleaved frame (DAB radio)
CIS    communication and information systems
cm    centimetre
CMA    Community Media Association
CMATZ    combined military air traffic zone
CMOS    complementary metal-oxide semiconductor
CNR    China National Radio
COAA    Centro de Observação Astronómica no Algarve
COD    carrier on-board delivery/ ies (aircraft carriers) 
COFDM    modulation scheme dividing a single digital signal across 1,000 or more signal carriers 
COM Port    Communications port
COMAO    composite air operations
COPE    Cadena de Ondas Populares Españolas
Corine    COoRdinate INformation on the Environment (as in: Corine CLC2006 file type)
COSPAR    Committee on Space Research
CPDLC    controller pilot data link communications 
CPL    commercial pilot licence 
cps    characters per second
CPU    central processing unit (PC) 
CQ    general call (e.g. in amateur radio) 
CQD    distress signal (pre-SOS)
CRC    Control and Reporting Centre
CRC    cyclical redundancy check
CRo    Ceský rozhlas (Czech Radio)
CRT    cathode ray tube (early TV)
CRT    cathode-ray tubes (e.g. in early television sets)
CSV    comma separated values (.csv file)
CTCSS    continuous tone-coded squelch system
CTOL    conventional take-off and landing
CTX    Charlie Tango eXtreme
CU    capacity unit (DAB radio)     
CU    capacity unit (DAB radio)     
CVOA    carrier operations areas
CW    continuous wave (Morse code)

D&D    distress and diversion
D/A    digital-to-analogue
DAAIS    danger area activity information service
DAB    digital audio broadcasting
DAB+    digital audio broadcasting plus (upgrade to the existing DAB system)
DAC    digital to analogue converter
DACT    dissimilar air combat training
DARC    Deutscher Amateur Radio Club e.V. (Eingetragener Verein = registered club)
DAT    digital audio tape
dB    decibel
dB/Hz    decibels relative to one hertz
dBi    decibel relative to an isotropic radiator
dBm    decibel referenced to one milliwatt
dBμV     decibel referenced to one microvolt
DC    direct current
DC    Douglas Commercial (for example, DC-3, DC-10)
DCR    digital convenience radio (Japan) 
DCS    digital coded squelch
DCW    digital chart of the world (a dataset)
DDC    digital down-conversion
DF    direction finder/finding
DGPS    differential global positioning system (see also: GPS)
DHCP    dynamic host configuration protocol 
DHFS    Defence Helicopter Flying School
DHL    Dalsey, Hillblom and Lynn (couriers and packaging service)
DIL    dual in-line
DIN    Deutsches Institut für Normung, or: Deutsche Industrie Norm (German Industry Standard) 
DIO    Defence Infrastructure Organisation
DIUx    Defence Innovation Unit Experimental 
DIY    Do-It-Yourself
DJ    disc jockey
DLL    dynamic-link library
DMC    Disco Mix Club
DME    distance measuring equipment
DMR    digital mobile radio
DNS    domain name server
DOK    letter and number combination used by the DARC to identify regional radio clubs
DominoEX    An IFK (Incremental Frequency Keying) mode
DOS    disk operating system
DPD    Deutscher Paketdienst (German Parcel Service)
DPDT    double-pole double-throw
dPMR    digital private mobile radio
DPRK    Democratic Peoples’ Republic of Korea (aka: North Korea)
DQPSK    Differential quadrature phase shift keying (e.g. in Bluetooth technology) 
DR    Danish Broadcasting Corporation
DRAP    Digital Radio Action Plan
DRM    Digital Radio Mondiale
DSC    digital selective calling
DSD/ DSD+    Digital Speech Decoder
DSLR    digital, single-lens reflex (camera)
DSP    digital signal processor (e.g.: DSP unit)
D-STAR    digital smart technologies for amateur radio
DSWCI    Danish Short Wave Club International 
DTI    Department of Trade and Industry
DTMF     dual tone multi frequency
DTT    digital terrestrial television
DUT    device under test
DVB-S2    second generation satellite digital video broadcasting
DVB-T    first generation terrestrial digital video broadcasting
DVB-T2    second generation terrestrial digital video broadcasting
DVD    digital versatile disc
DW    Deutsche Welle
DWD    Deutscher Wetterdienst (German Weather Service) 
DX    long distance
DXCC    DX Century Club
DXing    Receiving stations over a long distance (also: DXer) 
DXLD    DX Listening Digest    
DXpedition    a journey undertaken for Dxing purposes
DXTV    long-distance television reception
DZ    drop zone

E    East 
EAN    European Aviation Network
EASA    European Aviation Safety Agency
EAVD    enhanced airport vision display
EBU    European Broadcasting Union
ECBF    European Citizens’ Band Federation
ECC    European Communications Committee
ECDIS     electronic chart display and information system
ECKO    Eric Kirkham Code (Bakelite radios)
ECM    electronic countermeasure
ECSS    exalted carrier selectable sideband
ECU    engine control unit (cars) 
EDACS    enhanced digital access communication system
EDXC    European DX Council
EGD    United Kingdom danger area
EHT    extra-high tension (e.g.: old TV valve technology)
EIRP    effective isotropic radiated power
ELF    extremely low frequency (3 to 30Hz)
ELINT    electronic intelligence
eLoran (e-Loran)    enhanced long range navigation 
EMARSS    enhanced medium altitude reconnaissance and surveillance system
EMC    electromagnetic compatibility/ compliance
EME    Earth-moon-earth (moon bounce)
EMEDS    expeditionary medical support 
EMF    electromotive force
EMI    electromagnetic interference
EML    Eesti Mereväe Laev
ENOB    effective number of bits
EON    enhanced other network
EP    extended play
EPG    electronic programme guide
EPIRB    emergency position indicating radio beacon    
EPIRB    Emergency Position Indicating Radio Beacon (maritime)
eQSL    electronic QSL (also: e-QSO)
ERA    Elliniki Radiofonia (Greek Public Radio)
ERP    effective radiated power
ERT    Ellinikí Radiofonía Tileórasi
ERT    en route recovery team
ERTU    Egyptian Radio and Television Union
ESD    electrostatic discharge
ESN    emergency services network
ETA    estimated time of arrival
ETD    estimated time of departure
ETSI    European Telecommunications Standards Institute 
ETV    Emergency Tug Vessel (Coastguard)
EU    European Union
EUROCAE    European Organisation for Civil Aviation Equipment
EVP    electronic voice phenomena
EW    electronic warfare
EWTN    Eternal Word Television Network
ExtIO    external input/output

F    farad (SI derived unit of electrical capacitance)
F/R ratio    front-to-rear ratio (same as front-to-back ratio of an antenna)
F3E    a type of channeling modulation (see also: G3E)  
FAA    US Federal Aviation Administration
FAC    forward air controller
FARP    forward arming and refuelling point
FAS    Future Airspace Strategy
FASVIG    Future Airspace Strategy Visual Flight Rules Implementation Group
FAX    facsimile
FCC    Federal Communications Commission (USA)
FDD    flying display director
FDXA    Finnish DX Association
FEC    forward error correction
FET    field effect transistor
FFT    Fast Fourier Transform
FGS    Federal German Ship
FIC    fast information channel (DAB)
FIR    finite impulse response
FIS    flight information service
FL    flight level
FL    Florida
FLARM    portmanteau term for ‘flight-alarm’ (traffic awareness and collision avoidance technology)
FLEX    flexible wide area paging protocol
FLIDIGI/ Flidigi    fast, light digital modem application
FM    frequency modulation
FNS    Finnish Navy ship
FPGA     field-programmable gate array
FPS (fps)    frames per second
FRCN    Federal Radio Corporation of Nigeria
FRS    Fellow of the Royal Society
FS    French Ship
FS17    Flaming Sword 17
FSD    full-scale deflection
FSK    frequency shift keying (e.g. FSK315, FSK441, see below)
FSK441    a high-speed meteor scatter communications mode
FSM    field strength meter
ft    foot/feet
FT-8    a (new) digital mode 
FTDI    Future Technology Devices International (computer chip)
FTX    field training exercise

g    force of gravity/ gram (1000g = 1 kg)
G3E    a type of channeling modulation (see also: F3E)  
GA    general aviation/ Georgia (US)
GB    gigabyte
GBC    Gibraltar Broadcasting Corporation
gcc    GNU Compiler Collection
GCHQ    Government Communications Headquarters
GFSK    Gaussian frequency shift keying (e.g. in Bluetooth technology)
GHz    gigahertz
GLA    General Lighthouse Authority
G-LOC    G-induced loss of consciousness
GLONASS    globalnaya navigatsionnaya sputnikovaya sistema (Russian Loran equivalent)
GMDSS    global maritime distress and safety system
GMT    Greenwich Mean Time
GNSS    global navigation satellite system (EU)
GO/ NO-GO    a pass/fail test (or check) principle, using two boundary conditions or a binary classification
GOES    Geostationary Operational Environmental Satellite
GOS     General Overseas Service
GPIO    general-purpose input/output
GPO    General Post Office
GPS     global positioning system
GPSDO    GPS disciplined oscillator
GPU    graphics processing unit
GPX    GPS exchange format
GRAVES    Grand Réseau Adapté à la Veille Spatiale
GRI    group-repetition interval (Loran signals) 
GRT    Gross Registered Tonnage (vessels) 
GRT    gross registered tons (maritime vessels) 
GRTS    Gambia Radio and Television Service
GS    ground station
GSM    global system for mobile communications
GSM-R    GSM-Railway
GUI    graphical user interface

H    henry (SI unit of electrical inductance) 
H.264    ITU recommendation for advanced video coding for generic audiovisual services
HAHO    high altitude high opening
HAT    hardware attached on top
HAW    heavy airlift wing
HBA    Hospital Broadcasting Association
HCJB    The Voice of the Andes (Ecuadorian Religious Radio Station)
HD    high-definition
HDD    hard disk drive
HDMI    high-definition multimedia interface
HDMS    Her or His Danish Majesty's Ship
HDR    high data rate
HDSDR    high-definition software defined radio (software) 
Hellschreiber    an amateur radio mode displayed in ‘ticker-tape’ style (‘HELL’)
HEVC    high efficiency video coding (standard)
Hex    hexadecimal (as in: Hex code)
HF    high frequency (3 to 30MHz)
HFCC    High-Frequency Coordination Conference (a member of the ITU)
HFDL    high frequency data link
HFP    hands-free profile (e.g. in Bluetooth technology) 
HIMARS    high mobility artillery rocket system
HM    Her (or His) Majesty’s […]
HMCG    Her or His Majesty’s Coastguard
HMCS    Her or His Majesty's Canadian Ship
HMHS    Her or His Majesty’s Hospital Ship
HMI    human-machine interface
HMS    Her (or His) Majesty's Ship
HMSO     Her or His Majesty's Stationery Office
HNLMS    His or Her Dutch Majesty’s Ship
HNoMS    His or Her Norwegian Majesty's Ship
hPa    hectopascal
HPA-PLA    home plug alliance-power line adaptor
HQ    headquarters
hr    Hessischer Rundfunk
HTML    hypertext mark-up language
Hz    hertz (named after: Heinrich Hertz)

I/Q (IQ)    in-phase and quadrature
IAA    Irish Aviation Authority
IAF    Italian Air Force
IARU    International Amateur Radio Union
IATA    International Air Transport Association
IBA    Israel Broadcasting Authority
IBC    International Broadcasting Convention
IBOC    in-band, on-channel system (digital broadcasting)
IC    integrated circuit
ICAO    International Civil Aviation Organization
ICE    Integrated Communications Environment (military equipment) 
ICS    International Code of Signals (maritime)
ID    identification
IDAS    Icom Digital Advanced System (Scanning)
IEC    International Electrotechnical Commission (Geneva, Switzerland)
IEEE    Institute of Electrical and Electronics Engineers
IF    intermediate frequency
iFACTS    interim future area control tools support system (NATS)
IFCA    Inshore Fisheries Conservation Authority
IFDL    F-22 aircraft Intra Flight Data Link (for the F-22 aircraft)
IFF    identification friend or foe
IFK    incremental frequency keying
IFR    instrument-flight rules
IIP3    third-order input intercept point
IL    Illinois
ILR    Independent Local Radio
ILS    instrument landing system
IMD    intermodulation distortion
IMO    International Maritime Organization
in    inch/ inches
IOC    index of cooperation
IOM    Isle of Man
IoT    internet-of-things
IOTA    Islands on the Air
IP    initial point
IP    internet protocol (e.g. IP-NTP Server)
IP-3    third-order intercept point
IP66    enclosure rated as dust tight and protected against heavy seas or powerful jets of water
IPv4    Internet Protocol Version 4
IRC    international reply coupon/ Internet Relay Chat
IRIB    Islamic Republic of Iran Broadcasting
IRRS    Italian Radio Relay Service
ISAR    International Search and Rescue
ISBN    International Standard Book Number
ISCAT    mode for weak signal, long-distance, radio contact by meteor and Ionosphere scattering
ISDB/ ISDB-T    Integrated Services Digital Broadcasting
ISM    industrial, scientific and medical
ISS    International Space Station
ISTAR    information, surveillance, target acquisition and reconnaissance
ISWBG    International Short Wave Broadcast Guide
IT    information technology
ITU    International Telecommunication Union
ITV    Independent Television (UK TV network)

JRC    Japan Radio Company
JRTV    Jordan Radio and Television Corporation
JSWC    Japan Short Wave Club 
JT4    communications mode used, for example, in microwave earth-moon-earth communications
JT65    a digital mode (restricted to short messages), originally part of WSJT
JT6M    part of WSJT suite of digital weak signal software applications by Joe Taylor, K1JT.
JT-8    part of WSJT suite (see: WSJT)
JT9    an amateur radio digital mode
JTMS    a meteor scatter mode that uses MSK
JW    Joint Warrior

kb    kilobits
kB    kilobyte
kb/s    kilobits per second
KBD    Kaiser-Bessel-derived
kbps    kilobits per second
KBS    Korean Broadcasting System
KDM    Kongelige Danske Marine
kg    kilogram
kHz    kilohertz
KISS    keep it simple, stupid
KLM    Koninklijke Luchtvaart Maatschappij (Royal Dutch Airlines)
km    kilometre
km/h    kilometres per hour
KML    keyhole mark-up language
kn    knot
KNM    Kongelige Norske Marine
kSPS    kilo samples per second
kV    kilovolt
kW    kilowatt
k?    kiloohm

L    Left (runway)
LA    Louisiana
LACC    London Area Control Centre
LAN    local area network
LandSAR    land search and rescue
LARS    lower airspace radar service
LAV    light armoured vehicle
LCD    liquid crystal display
LCR    inductance, capacitance and resistance
LCRS    limited coast radio station
LE    low-energy
LED    light emitting diode
LF    low frequency (30 to 300kHz)
LIDAR (or: LiDAR)    light-detection and ranging
LLC    limited liability company
LM&S    Long, medium and short wave (RU column)
LNA    low noise amplifier
LNS    Lithuanian Ship
LNWR    London North-Western Railway
LO    local oscillator
LOF    lowest observed frequency
Loran    long range navigation (see also: eLoran, GLONASS) 
LOS    loss of signal 
LoTW    Logbook of the World
LP    long play
LPAT    low power ADS-B transceiver
LPD/LPI    low probability of detection / low probability of interception (intra-flight data link)
LRAD    Long-range acoustic device
LRIT    long-range identification and tracking (a form of maritime AIS system) 
LSB    lower sideband (see: USB)
LSF    low-sampling frequency (DAB radio technology)
LSWC    Lincoln Short Wave Club
LTCC    London Terminal Control Centre 
LTE    long-term evolution
LTR    E F Johnson logic trunked radio
LUF    lowest-useable frequency (see: MUF)
LUT    local user terminal
LV    lightvessel
LVNS    Latvian Naval Ship

m    metre
M    million
MA     Massachusetts
MA    Master of Arts
mA    milliampere
MACAN    Mando Aéreo de Canarias
MADL    Multifunction Advanced Data Link (communications link among F-35 aircraft)
mAh    milliampere hour
MAI    Moscow Aviation Institute
MAIT    multi agency incident transfer
MANPADS    Man-portable air defence system
MAOT    mobile air operations team
MATZ    military aerodrome traffic zone
MB    megabyte
mb    millibar
MBE    Member of the British Empire
Mbps    megabits per second
MCA    Maritime and Coastguard Agency
MCC     Mission Control Centre
MCX    micro coaxial
MDR    Mitteldeutscher Rundfunk
MDS    minimum detectable signal
ME    Maine
METAR    meteorological terminal aviation routine weather report
MF    medium frequency (300kHz to 3MHz)
MFSK    multiple frequency shift keying (e.g.: MFSK144,    a data mode)
MHz    megahertz
MI    Michigan
MicroGRAM    micro GPS receiver application nodule
microSD card    micro Secure Digital cards (computer storage)
Mlat    Multilateration
MLB    magnetic long wire balun
mm    millimetre
MMSI    maritime mobile service identity (vessels)
MOD    Ministry of Defence
Mode-S    Secondary Surveillance Radar process
MOF    maximum observed frequency
MotoTBRO    Motorola’s proprietary version of digital mobile radio
MP    Member of Parliament
MP3     MPEG-1 or MPEG-2 Audio Layer III
MPEG    Moving Picture Experts Group (e.g.: MPEG-4)
mph    miles per hour
MPT1327    A trunked radio system (scanning)
MR    Magyar Rádió
MRC    Marine Resources Committee
MRCC    maritime rescue coordination centre
MS    Microsoft
ms    millisecond
MSC    main service channel (DAB radio) 
MSG    Master’s Service Gram
MSI    maritime safety information (MSI broadcasts/ frequencies)
MSK    minimum-shift keying 
MSPS    mega samples per second
MT63    an amateur radio digital mode
MUF    maximum usable frequency (see: LUF)
MultiPSK    A type of decoder software
MUX    multiplex or multiplexer
mV    millivolt
MV    motor vessel
MW    megawatt; medium wave
mW    milliwatt

NAC    network access code (e.g. P25 mode)
NAFFI    Navy, Army and Air Force Institutes
NARSA    Northern Amateur Radio Societies Association
NAS    Naval Air Station
NASA    National Aeronautics and Space Administration
NASWA    North American Shortwave Association
NATO    North Atlantic Treaty Organization
NATS    NATS Holdings (formerly National Air Traffic Services)    
NAVTEX    navigational telex (maritime communications, weather warnings)
NB    New Brunswick
NBDP    narrow-band direct printing (a form of navigational HF NAVTEX) 
NBFM    narrow band frequency modulation
NCI    National Coastwatch Institution
NDB    non-directional beacon (e.g.: aeronautical, maritime; NDB DXing)
NDXN    open-standard technical protocol for mobile communications (ICOM/ Kenwood). 
NEC    numerical electromagnetics code (as in 4NEC2, NEC2; also: nec)
nF    nanofarad
NFM    narrow FM
NHK    Nippon Hoso Kyokai
NiCad    nickel-cadmium (battery type)
NiMH    nickel hydride (battery type) 
NIRT    National Iranian Radio and Television
NJ    New Jersey
NL    Newfoundland and Labrador
nm    nanometre
nmi    nautical mile(s)
NMOC    National Maritime Operations Centre
NOAA    National Oceanic and Atmospheric Administration (USA)
NOOBS    new out of the box software
NORAD    North American Aerospace Defense Command
NOTAM    notice to airmen or mariners
NPN    bipolar transistor with a layer of P-doped semiconductor between two N-doped layers
NPR    National Public Radio
nr.    near
NRF    NATO Response Force
NRK    Norsk Rikskringkasting (Norwegian Broadcasting Corporation)
NRP    Navio da República Portuguesa
NS    Nova Scotia
NTP    network time protocol
NTSC    National Television Standards Committee
NU    Nunavut
NVIS    near vertical incidence sky wave
NWR    NOAA Weather Radio (see: NOAA)
NXDN    narrowband digital protocol developed by Icom and the JVCKENWOOD
NY    New York

OB    outside broadcast
Odroid    a type of miniature PC
Ofcom    Office of Communications 
OFDM    Orthogonal Frequency Division Multiplex (wireless technology)
OFDM    orthogonal frequency division multiplexing
OGBC    Ogun State Broadcasting Corporation
OIRT    Organisation Internationale de Radiodiffusion et de Télévision
OLE    Object linking and embedding
Olivia/ MFSK    amateur radio digital mode designed for challenging conditions
ON    Ontario
ONO    or near offer
ORF    Österreichischer Rundfunk
ORTC    Office de Radio et Télévision des Comores (Islands)
OS    operating system (computers, smartphones)
OS    Ordnance Survey
OSMOCOM    Open Source Mobile Communication (project)
OSS    Office of Strategic Services
OVNO    or very near offer
oz    ounce

P&P    postage & packaging
P14    an amateur radio mode
P25/ P25 Phase 2    a standards-suite for digital radio, used by US public safety and government organisations
PA    Piper aircraft
PA    power amplifier
PACTOR    portmanteau term of ‘Packet Radio’ and ‘AMTOR’
PAL    phase alternate (or: alternating) line
PBN    performance-based navigation (aircraft)
PBT    pass band tuning
PC    personal computer
PCB    printed circuit board
PCM    pulse-code modulation (DAB, see also: ADPCM)
PDA    public display authority
PDF/ .pdf    portable document format (.pdf)
PEP    peak envelope power
pF    picofarad
PF    pilot flying
PFD    personal floatation device 
PG    parental guidance
PGA    programmable gain amplifier
Pi    a microcomputer (Raspberry Pi)
PIREP    pilot report
pk-pk    peak-to-peak
PL-259    UHF plug (coaxial) for SO-239 socket
PLA    power-line adaptor
PLB    Personal Locator Beacon (maritime)
PLL    phase locked loop
PLT    power-line transmitter/ transmission
PM    pilot monitoring
PMR446    private mobile radio (on 446MHz)
PMSE    programme-making and special events (license category)
PNA    Prefectura Naval Argentina (Buenos Aires)
PNG (.png)    portable network graphics 
POCC    port-operations control centre
POCSAG    Post Office Code Standardisation Advisory Group
ppb    parts per billion
PPL    Private Pilot Licence
ppm    parts per million
PSB    public service broadcasting
PSK    phase shift keying (e.g.: PSK31, PSK63)
PSU    power supply unit
PTFE    polytetrafluoroethylene
PTT    push to talk or press to transmit
PVC    polyvinyl chloride
PW    Practical Wireless (sister magazine to RadioUser)
PWAP    private wide area paging
PWP    PW Publishing

Q code    radiotelegraphy brevity code
QAM    quadrature amplitude modulation
QC    Quebec
QFE    Q code for atmospheric pressure at aerodrome elevation (or at runway threshold)
QFH    quadrafiliar (or quadrafilar) helical (an antenna form)
QMC    Qatar Media Corporation
QNE    Q code for the indicated altitude at the landing runway threshold
QNH    Q code for altimeter pressure setting to indicate altitude AMSL
QPSK    quadrature phase shift
QRA    Q code for what is the name of your station?
QRA    Quick reaction alert
QRB    Q code for the distance between two stations
QRM    Q code for interference (man-made)
QRN    Q code for noise (natural, static)
QRP    Q code for low-power
QSB    Q code for fading
QSL    Q code for acknowledgement of receipt (QSL card)
QSO    Q code for radio contact
QSPK    quadrature phase shift keying
QSX    Q code for will you listen to (callsign(s)) on xxx kHz (or MHz)
QSY    Q code for change to transmission on another frequency
QTH    Q code for a station’s location
QTHR    Q code for at the registered address for my callsign
QWI    qualified weapons instructor

R    Resistance (?)
R    Right (runway)
R&D    research and development
R&S    Rohde & Schwarz
RA    Radiocommunications Agency (superseded by Ofcom)
RA    resolution advisory
RAC    Royal Automobile Club
RAE    Radiodifusión Argentina al Exterior
RAF    Royal Air Force
Rai    Radiotelevisione Italiana S.p.A.
RAIN    Radio and Internet News (summit) 
RAJAR    Radio Joint Audience Research
RAM    Random access memory
RAPCON    radar approach control
RCA    Radio Corporation of America
RCC    Rescue Coordination Centre
RCF    Radio Communications Foundation 
RCI    Radio Canada International
RDF    radio direction finding
RDS    radio data system
RECAT-EU    European wake vortex re-categorisation
RF    radio frequency
RFA    Radio Free Asia
RFE    Radio Free Europe
RFFS    rescue and firefighting service
RFI    radio frequency interference; Radio France Internationale (context)
RFID    Radio frequency identification (as in: RFID-tag)
RFP    request for proposals
RIAT    Royal International Air Tattoo
RIB    rigid inflatable boat
RL    Radio Liberty
RLC    Royal Logistics Corps
RMC    Radio Monte Carlo
RMRC    Rhein-Main Radio Club
RMS     Root-mean-square (power measurement) 
RMS    Royal Mail Ship
RMZ     radio mandatory zone
RN    Royal Navy
RNAS    Royal Naval Air Station
RNAV    area navigation (means of lateral navigation independent of ground aids)
RNE    Radio Nacional de España
RNI    Radio Northsea International
RNLI    Royal National Lifeboat Institution
RNZI    Radio New Zealand International
RoHS    restriction of the use of certain hazardous substances (category of legislation)
ROS    an amateur radio digital mode using multiple tones at three speeds
ROV    remotely operated vehicle
ROW    Rest of (the) world (subscription rates) 
RP    Red Pitaya
rpm    revolutions per minute
RPU    receiver protection unit
RRH    remote radar head
RRI    Radio Romania International
RRP    recommended retail price
RSGB    Radio Society of Great Britain
RSI    Radio Slovakia International
RSL    Restricted Service Licence
RSP/RSP2    Radio Spectrum Processor hardware from SDRplay Limited
RSS    rich site summary
RSSI     received signal strength indication/ indicator
RT    radiotelephony/ Russia Today
RTBF    Radio Télévision Belge de la Communauté Française
RTÉ    Raidió Teilifís Éireann
RTL    Radio Television Luxembourg
RTM    Radio Televisyen Malaysia
RTP    Rádiotelevisão Portuguesa
RTT    Radio Télévision Tunisienne
RTTY    radioteletype 
RTV    Radiotelevizija (Slovenija)
RTVS    Rozhlas a televízia Slovenska
RU    RadioUser (The best radio magazine in the world) 
RVSM    Reduced vertical separation minima (aircraft routes)
RW    rotary wing
RX    receiver
RYA    Royal Yachting Association (UK) 

s    second
SaaS    software as a service (business model)
SACC DT    Situational Awareness, Command and Control Delivery Team
SADR    Sahrawi Arab Democratic Republic
SAME    specific area message encoding (see: NWR) 
SANR    small airborne networking radio
SAOC    School of Air Operations Control
SAR    search and rescue
SARSAT    search and rescue satellite aided tracking
SAS    Special Air Service
SATA    serial AT attachment
SATCOM    satellite communications
SAW    surface acoustic wave (as in: SAW Filter)
SBARC    South Bristol Amateur Radio Club
SBAS    space-based augmentation system (satellite technology) 
SBC    Saudi Broadcasting Corporation
SBC    single-board computer
SBR     spectral-band replication (e.g. in DAB) 
SCBO    Swiss CB Organisation
SCR    short range certificate
SD Card    secure digital card 
SD    standard definition
SDR    software defined radio/ receiver
SDXF    Sveriges DX-Förbund
SECAM    séquentiel couleur avec mémoire
SER    Sociedad Española de Radiodifusión
SESAR    Single European Sky ATM Research
SF    Special Force(s)
SFN    single-frequency network(s) (DAB)
SHF    super high frequency (3 to 30GHz)
SI    Système International (International System) Measurement System 
SIC    Sociedade Independente de Comunicação
SID    standard instrument departure
SIG    Special Interest Group (e.g. in ARCs and regulatory issues)
SIGINT    signals intelligence
SIM    subscriber identity module
SINAD    signal-to-noise and distortion ratio
SINCGARS    single channel ground and airborne radio system
SINPO    signal strength, interference, noise, propagation and overall merit (SINPO code) 
SIO    signal strength, interference and overall merit
SIP    standard instrument procedure
SITOR-B    simplex teletype over radio mode B
SITREP    situation report
SLOP    Strategic lateral offset procedure (aircraft collision avoidance) 
SLR    single lens reflex
SMA    subminiature version A (coaxial connector)
SMD    surface mount device
SME    subject matter expertise
SMS    short message service
SNR    signal-to-noise ratio
SNRT    Société Nationale de Radiodiffusion et de Télévision (Morocco)
SO-239    A UHF socket (coaxial) for a PL-259 plug
SoC    system on a chip
SOCEUR    US Special Operations Command Europe
SOCOM    Special Operations Command
SOF    Special Operations Force
SOFEX    Special Operations Forces Exhibition and Conference
SOL    short, open and load
SOLAS    safety of life at sea
SOP    standard operating procedure
SOS    distress signal
SOTA    Summits on the Air
SPG    a data format 
SPS    Spanish Naval Ship
SPTA    Salisbury Plain Training Area
SQB    a database file in the PlanePlotter aircraft tracking software 
SR    symbol rate 
SRC    Stryker Radio Club
SRo    Slovenský rozhlas
SRR    Societatea Româna de Radiodifuziune
SRTC    Sudan Radio and Television Corporation
SRTM    shuttle radar topography mission (map-making)
SRTV    Radio and Television Syria
SS    steamship
SSB    single sideband (USB and LSB)
SSD    solid state drive
SSID    service set identifier
SSN    Smoothed-sunspot number (propagation prediction)
SSR    secondary surveillance radar
SSTV    slow scan television
STAR    standard terminal arrival route
STARTEX    start of exercise
STEM    science, technology, engineering and mathematics
STOL    short take-off and landing
STOVL    short take-off and vertical landing
STP    shielded twisted pair
SWG    standard wire gauge
SWL    short wave listener (SWLing: shortwave listening) 
SWR    standing wave ratio (antennas) 
SWR    Südwestrundfunk
SYNOP    surface synoptic observations

TACAN    tactical air navigation system (TACAN routes)
TB    terabyte
TBS    time based separation 
TCAS    traffic collision avoidance system
TCCO    time-compensated crystal oscillator (e.g. CB transceivers)
TCP (Network)    Transmission Control Protocol/Internet Protocol
TCP    transmission control protocol
TDMA    time division multiple access
T-DMB    Terrestrial Digital Multimedia Broadcasting.    
TEP    trans-equatorial propagation 
TETRA    terrestrial trunked radio
TFL    Transport for London 
TFT    thin-film transistor
THD    total harmonic distortion
THROB    A data mode relying on DSP (see above) techniques
THROB    A unique data mode that relies heavily on DSP techniques
TMC    thrust management computer (in aviation)
TNC    terminal node controller
TNC    Threaded Neill-Concelman (coaxial connector)
TOTP    Top of the Pops
TRT    Turkish Radio and Television Corporation
T-SQL    tone-squelch (e.g. on a scanner)
T-SQL    Tone-squelch (e.g. on a scanner)
TTL    time-to-live (a message format in Bluetooth Mesh technology)
TUHD    Terrestrial Ultra-High Definition (TV)
TV    television
TVES    Televisora Venezolana Social
TVI    Télévision Indépendante (Belgium)
TWR    Trans World Radio
TX    transmitter

UAE    United Arab Emirates
UAP    unidentified aerial phenomenon
UART    universal asynchronous receiver/transmitter
UAS    unmanned aerial system
UFO    unidentified flying object
UHF    ultra-high frequency (300MHz to 3GHz)
UK    United Kingdom
UK40    The 40 CB channels in the 27MHz band in the UK 
UKFM    UK FM 27/81 CB channels
UKMFTS    UK Military Flying Training System
UKRAA    UK Radio Astronomy Association
UN    United Nations
UNESCO    United Nations Educational, Scientific and Cultural Organization
UNID, Unid.    unidentified
UPI    United Press International (News Service) 
URL    uniform resource locator (website address) 
US    United States
USA    United States of America
USAF    United States Air Force
USAREUR    United States Army Europe
USB    universal serial bus (e.g. USB adapter, USB port) 
USB    upper sideband
USNS    United States Navy Ship
USPS    United States Postal Service
USS    United States Ship (a commissioned ship of the US Navy)
USSR    Union of Soviet Socialist Republics (Soviet Union)
USV    unmanned surface vehicle
UTC    Universal Time Coordinated
UV    Ultraviolet
UXDF    Utility DXers Forum

V    Volt (SI derived unit of electrical potential)
v/ v.    version (of software) 
VA    Virginia (USA)
VAC    virtual audio cable
VAT    value added tax
VCCS    voice communications and control system
VCO    voltage controlled oscillator
VCS    voice channel spacing
VDF    VHF direction finder
VDSMS    VHF-FM digital small message services
-ve    negative
-ve    negative
VFO    variable frequency oscillator
VFR    visual flight rules
VHF    very high frequency (30 to 300MHz)
VIS    vertical interval signalling
VJTF    Very High Readiness Joint Task Force 
VLF    very low frequency (3 to 30kHz)
VMAP0    A vector dataset representing a Digital Chart of the World (DCW) dataset
VMRS    Volunteer Marine Rescue Service
VNA    vector network analyser
VOA    Voice of America
VOACAP    Voice of America Coverage Analysis Program
VOAR    Voice of Adventist Radio
VOCM    Voice of the Common Man
VoIP    voice over internet protocol
VOIRI    Voice of the Islamic Republic of Iran
VOLMET    meteorological information for aircraft in flight
VOR    VHF omnidirectional radio range (navigational system, beacon)
VOX    voice-activated transmit/ voice-operated control 
VRP    visual reference/ reporting point
VRT    Vlaamse Radio- en Televisieomroeporganisatie
VSAT    very small aperture terminal
VSC    voice-scanning (a scanner function) 
V-Scanner    virtual scanner
VSWR    voltage standing wave ratio
VTS    vessel traffic service
VUX    voice-user experience 
VW    Volkswagen

W    watt (SI derived unit for power)
WACAL    World Association of Christian Radio Amateurs
WAF    Wave-form audio file format (extension: .wav)
WARC    World Administrative Radio Conference
WAS    Worked All States
WAVE    A Microsoft audio file format (also: WAVEEXTENSIBLE) 
WAZ    Worked All Zones
WB    wideband
WDH    Width-depth-height (dimensions)
WDM    windows driver model
WDR    Westdeutscher Rundfunk
WebSDR    online SDR receiver
WEEE    Waste Electrical and Electronic Equipment (EU Directive/ Legislation)
WEF    World Economic Forum 
WEFAX    weather facsimile
WFM    wide FM
WHRI    World Radio Harvest International
WMFS    West Midlands Fire Service
WNW    wideband networking waveform
WPM    words per minute 
WRC    World Radio Conference 
WRMI    Radio Miami International
WRN    World Radio Network
WRTH    World Radio TV Handbook
WSJT    Weak Signals Joe Taylor
WSJT-X    A component of WSJT
WSPR    Another component of WSJT (e.g.: WSPRnet) 
WSPRnet    Weak Signal Propagation Reporter Network
WTR    Wireless Telegraphy Register (publication) 
WWDXC    World Wide DX Club 
WWI    World War One
WWII    World War Two

xHE-AAC    extended, high-efficiency advanced audio coding (e.g.: DAB)
XML    extensible mark-up language
XYL    (the) wife

Yagi    A highly directional and selective shortwave antenna
YL    young lady
YLE    Yleisradio Oy (Finnish Broadcasting Company)
YOTA    Youngsters on the Air (an RSGB initiative)

Z    impedance
ZDF    Zweites Deutsches Fernsehen (Second German TV Chain Network, see: ARD) 
ZF    Zwischenfrequenz (intermediate frequency) 
ZNBC    Zambia National Broadcasting Corporation
ZS    ITU callsign prefix for the Republic of South Africa
Zulu    UTC

?    ohm