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DX Glossary and Abbreviations

A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  Q  R  S  T  U  V  W  X  Y  other  notes

 
 A   to Page Top

AA
- Arabic language

ABC
- Australian Broadcasting Corporation
- American Broadcasting Company

absorption
- reduction of signal strength because of refraction in the ionosphere

ABU
- Asia-Pacific Broadcasting Union

AC
- adult contemporary music
- alternating current

ACMA
- Australian Communications and Media Authority (equivalent to FCC in the US)

active antenna
- a small antenna with an amplifier, designed to take as little space as possible, usually meant to be used indoors or on the roof

Af
- Africa

AFN
- American Forces Network, a service of AFRTS

AFRTS
- American Forces Radio and Television Service

AGC
- automatic gain control

A-Index
- a measure of geomagnetic activity, ranging in value between 0 and 400, derived from the value of K-Index; a low value generally indicates good long-distance MW reception; the mid-latitude A-Index is released every three hours by the US Space Environment Center

AIH
- short for Aihkiniemi, the best DXpedition site in the world

AIR
- All India Radio

AM
- amplitude modulation
- the mediumwave band (frequency range 520-1700 kHz in the Western hemisphere or 531-1702 in the Eastern hemisphere)

amplitude
- the strength or height of the electromagnetic (radio) wave

amplitude modulation (AM)
- a modulation technique in which the transmitted radio wave (or more specifically the amplitude of the carrier wave) is varied in accordance with the audio signal being broadcast, distinguished from frequency modulation (FM)

antenna
- a device connected to a transmitter to radiate electromagnetic energy during transmission or a device connected to a receiver to collect such energy during reception

antenna tuner
- a device installed between a receiver and an antenna to match the receiver impedance to the antenna impedance to minimize the loss of signal strength

Ap-Index
- an averaged planetary A-index based on data from a set of specific measuring stations

ARD
- Arbeitsgemeinschaft der öffentlich-rechtlichen Rundfunkanstalten der Bundesrepublik Deutschland

As
- Asia

attenuator (att)
- a circuit in a receiver or antenna tuner to decrease its sensitivity, measured in decibels, used in a situation when the desired signal is blocked by a very strong interfering signal

ATU
- African Telecommunications Union

aurora
- a visual phenomenon of changing coloured patterns which occurs during high geomagnetic activity in the high-latitude night sky; normally auroras occur 100-250 kilometers above the ground; called "aurora borealis" in the Northern hemisphere and "aurora australis" in the Southern hemisphere; aurora is caused by collisions between atmospheric gases and precipitating charged particles

auroral conditions
- during very high solar activity, the ionosphere absorbs skyway signals in very northern and very southern latitudes, allowing signals from closer to the Equator to be heard, with less interference than normally

auroral propagation
- propagation of VHF signals via refraction by ionized areas around the North or South pole, occurs usually after solar storms

automatic gain control (AGC)
- a circuit which adjusts the amplification level of the received signal to maintain steady volume level; in many receivers the AGC can be set off or on, and the AGC discharge time can be adjusted

AWR
- Adventist World Radio

 B   to Page Top

balun
- a device, a transformer, used to couple a balanced device or antenna wire to an unbalanced device or antenna wire, often used to join a copper wire antenna to a coax cable
- abbreviation for "balanced to unbalanced"

band
- the frequency spectrum between two defined limits; e.g. high frequencies, also known as the shortwave band (3-30 MHz) or a portion of it, e.g. the 60-meter band (4750-5060 kHz); c.f. tropical bands
- a set of frequencies assigned for a particular use

bandpass
- the frequency range that a filter in the receiver permits to pass through; the range between the lower and upper frequency is the passband

bandpass filter
- a device or circuit that allows signals within a certain range of frequencies to pass through but rejects other unwanted frequencies

bandscan
- a list of stations received at a particular location with normal equipment (as opposed to DX loggings of rare and unusual stations received)

bandwidth
- the width of the frequency range used by a radio signal or a receiver

BBC
- British Broadcasting Corporation; BBC's foreign service, the BBC World Service, is the world's best known and most listened to international radio broadcaster

BBCM
- BBC Monitoring Service

Bc
- broadcasting/broadcast

BCB
- abbreviation for the AM (MW) broadcast band

BCC
- Broadcasting Corporation of China

BCL
- abbreviation for broadcast listener, a person who listens to international broadcasting stations because of the program content (sometimes used as opposed to a DXer who listens to international broadcasting mainly if and because they are difficult to catch)

beacon
- a utility station transmitting a signal for navigation purposes

beam antenna
- a transmitting or receiving antenna that concentrates more transmitter power or amplifies signals received from a particular direction

beat frequency oscillator
- a circuit in a receiver that produces an internally-generated carrier to enable reception of CW and SSB signals

beverage antenna
- a horizontal longwire antenna designed for directional reception of low-frequency vertically polarized signals, consisting of a wire at least two wavelengths long, connected to the receiver and grounded through a resistor in the opposite end; in practise used especially by MW DXers

BFBS
- British Forces Broadcasting Service

BFO
- beat frequency oscillator

broadcasting
- transmissions that are intended for the general public

BS
- broadcasting station/service

BSKSA
- Broadcasting Service of the Kingdom of Saudi Arabia

 C   to Page Top

Ca
- Central America

call sign
- a station identifier, represented by a combination of characters that is used to identify an authorized broadcasting station; e.g. in the US call signs generally are combinations of three or four letters and begin with W or K

CARACOL
- Primera Cadena Radial Colombiana

carrier
- the unmodulated signal of a radio transmitter; types of analog modulation of a carrier are amplitude modulation (AM), frequency modulation (FM) and phase modulation

CBC
- Canadian Broadcasting Corporation (Société Radio-Canada in French)

CBS
- Columbia Broadcasting Company
- Central Broadcasting System (of Taiwan)

c/d
- close-down, the end of the transmission; synonym: sign-off (s/off)

CE
- chief engineer

channel
- the frequency on which a radio transmission takes place

chief engineer
- a person at a broadcasting station who is in charge of the technical maintenance and development of the station; usually the best person for DXers to address their reception reports to

clandestine
- a politically motivated unauthorized broadcasting station operating in secrecy, c.f. pirate

CNN
- Cable News Network

CNR
- China National Radio

co-channel interference
- interference from stations on frequencies next to the desired signal

Coordinated Universal Time (UTC)
- equivalent to mean solar time at the prime meridian (0° longitude) which passes through Greenwich, United Kingdom, formerly known as Greenwich Mean Time (GMT); UTC is the standard time used by DXers around the world to express time; UTC is e.g. five hours ahead of Eastern standard time and four hours ahead of Eastern Daylight Savings Time
- synonyms: World Time, Universal Time (UT), Zulu Time, Z Time

COPE
- Cadena de Ondas Populares Españoles

CRI
- China Radio International

CRTC
- Canadian Radio-television and Telecommunications Commission

CRTV
- Cameroon Radio Television

CW
- abbreviation for continuous wave, referring to an unmodulated radio wave
- transmissions in morse code

CX
- (reception) conditions

 D   to Page Top

DAB
- Digital Audio Broadcast; a digital radio system co-ordinated by the World DAB Forum

dB
- abbreviation for decibel

DBS
- direct broadcast satellite

DC
- direct current

D-layer
- the lowest region of the ionosphere in the altitude of 50-90 km; fades away after sunset; affects radio propagation by absorbing signals below about 7 MHz during daytime hours

decibel (dB)
- the ratio between two signal power levels, expressed on a logarithmic scale; e.g. a 3-decibel increase means a doubling of power and a 20-decibel increase means a 100-fold power increase; in amplifiers the gain is often expressed in decibels

dipole antenna
- an antenna type optimized for the desired frequency; in total 1/2 wavelength long and consisting of two 1/4-wavelength wires to opposite directions, connected in the center to a feed line; ideally, a dipole antenna should be more than 1/2 wavelength above the ground

DRM
- Digital Radio Mondiale, a global initiative to introduce digital transmissions on mediumwave and shortwave

DSP
- digital signal processing

DW
- Deutsche Welle

DX
- "D" stands for distance and "X" for unknown
- short for DXing
- a far-away station that is hard to hear in a particular location on a particular frequency

DXing
- the hobby of listening to far-away radio stations; the hobbyist is called a DXer

DXing.info
- your number one DX site on the Internet

DXpedition
- abbreviated from DX-expedition; a DXer's trip to a remote location in search of better reception conditions, less interference and more space for antennae

DX test
- a special transmission by a radio station to make it easier for DXers to hear the station

dynamic range
- describes the ratio of the faintest sound to the loudest sound in a receiver, measured in decibels; in practise it measures how well a receiver can deal with overloading caused by strong signals; any measure above 100 decibels is considered good

 E   to Page Top

EBU
- European Broadcasting Union

EDXC
- European DX Council

EE
- English language

E-layer
- a layer in the ionosphere above the D-layer at an altitude of 85-140 km; fades away after sunset; the layer can either absorb or reflect radio signals, occasionally the so-called sporadic-E propagation (E-skip) reflects and provides clear signals on VHF frequencies

effective radiated power
- output of a transmitter multiplied by the gain of an antenna

eQSL
- a QSL in electronic form, such as an email or a social media message

ERA
- Elliniki Radiophonia

ERP
- effective radiated power

ERT
- Elliniki Radiophonia Tileorassi

ERTU
- Egyptian Radio & TV Union

Eu
- Europe

 F   to Page Top

FCC
- Federal Communications Commission

FEBC
- Far East Broadcasting Company

FF
- French language

FFW
- abbreviation for "first from the world"; e.g. a DXer who has a QSL confirming the earliest date of listening (as compared to other known verifications) from a particular radio station owns the FFF; other abbreviations such as SFW (second from world) or FFE (first from Europe) can be derived

F-layer
- the upper layer of the ionosphere above the E-layer at an altitude of 120 to 1500 km; consisting of two parts, the F1 at an altitude of 170 kilometers and the F2 at 250 km merging together after sunset and breaking apart again after sunrise; reflects mediumwave and shortwave radio signals enabling very long-range reception

filter
- a circuit or device that selectively sorts frequencies allowing the desired range of frequencies to pass while suppressing others; used to reduce noise and co-channel interference

FM
- frequency modulation
- the FM band (87.5 - 108 MHz in most countries, 76-90 MHz in Japan)

FRCN
- Federal Radio Corporation of Nigeria

frequency
- the number of complete cycles per second for an oscillating current; measured in hertz (Hz), so if a current completes one cycle per second, then the frequency is 1 Hz; larger units of frequency include the kilohertz (kHz) representing thousands (1,000's) of cycles per second, the megahertz (MHz) representing millions (1,000,000's) of cycles per second, and the gigahertz (GHz) representing billions (1,000,000,000's) of cycles per second
- the frequency of a signal is related to the wavelength: divide 300,000 by the frequency in kilohertz and you get the wavelength in meters (e.g. 300,000 : 15,400 kHz = 19,4 meters); conversely divide 300,000 by the frequency in kHz and you get the wavelength in meters
- the radio spectrum is divided into the following frequency ranges:

  • VLF Very Low Frequencies 3-30 kHz
  • LF Low Frequencies 30-300 kHz (incl. LW)
  • MF Medium Frequencies 300-3000 kHz (incl. MW)
  • HF High Frequencies 3-30 MHz (shortwave)
  • VHF Very High Frequencies 30-300 MHz
  • UHF Ultra High Frequencies 300-3000 MHz
  • SHF Super High Frequencies 3-30 GHz
  • EHF Extremely High Frequencies 30-300 GHz

frequency modulation
- a modulation technique that varies (i.e. modulates) the carrier frequency of a transmitter in accordance with variations in the strength of the modulating audio signal

f-up
- follow-up (reception report); a reception report sent to the station when no reply has been received for the original report

 G   to Page Top

gain
- an increase in the strength of the signal radiated or received by an antenna from a certain direction

geomagnetic activity
- variations and disturbances in the geomagnetic field; these variations are the result of the solar wind originating from the sun, causing the earth to be hit by plasma carrying electrical energy; geomagnetic activity consists of storms, substorms and aurora; c.f. solar activity; the range of activity is subdivided into five classifications: quiet, unsettled, active, stormy and major storm; it has been suggested that geomagnetic activity peaks shortly before the 11-year sunspot maximum and about two years after the sunsport maximum

geomagnetic field
- the magnetic field in and around the earth; the intensity of the magnetic field at the earth's surface is about 0.32 gauss at the equator and 0.62 gauss at the North pole; the field is dynamic and undergoes changes (geomagnetic activity) resulting from solar activity

geomagnetic storm
- a worldwide disturbance of the earth's geomagnetic field, distinct from regular diurnal variations (cf. ionospheric storm); classified as follows:

  • minor storm - Ap-Index 30-49
  • major storm - Ap-Index 50-99
  • severe storm - Ap-Index 100 or more

GG
- German language

GHz
- gigahertz, equal to 1000 megahertz (MHz) or 1,000,000 kilohertz (kHz)

GM
- general manager (of a radio station)

GMT
- Greenwich Mean Time, see also Coordinated Universal Time

great circle map
- a round world map projection relative to the location in question so that user location is in the center, preserving true directions but distorting dimensions; a great circle path to anywhere is then a direct line on the map

great circle path
- the shortest path for a radio signal between any two points on earth

Greenwich Mean Time
- the international time standard derived from the 0° longitude at Greenwich; nowadays referred to as Coordinated Universal Time

ground
- a connection to a zero voltage point, in practise usually the earth

ground wave propagation
- radio waves that travel along the surface of the earth, even beyond the horizon (but without reflecting via the ionosphere)

GTRK
- Gosudarstvennaya Teleradiokompaniya (regional branches of VGTRK)

 H   to Page Top

ham
- an amateur radio operator; not to be confused with DXer and DXing

harmonic
- a frequency that is an integer multiple (often two times) of the intended fundamental frequency

hertz (Hz)
- one complete cycle of the radio wave per second (see kilohertz, frequency)

heterodyne (het)
- a high-pitched sound caused by two carriers interfering with each other

HF
- high frequencies, i.e. shortwave (3-30 MHz)

 I   to Page Top

IBA
- Israel Broadcasting Authority

IBB
- International Broadcasting Bureau

ID
- abbreviation for (station) identification

impedance
- the opposition that an electronic component or circuit presents to the flow of electric current, composed of resistance (measured in ohms) and reactance; ideally the impedance of various receiving equipment should be roughly the same

intermediate frequency (IF)
- a frequency to which a carrier frequency is shifted in the receiver as an intermediate step in reception

International Reply Coupon (IRC)
- a coupon that can be purchased from a post office and may be exchanged in any member country of the Universal Postal Union for the minimum postage payable on international unregistered airmail letters; often used by DXers along with their reception reports as means to cover return postage for the radio station

ionosphere
- series of concentric ionized layers forming part of the upper atmosphere of the earth from around 50 up to 600 km, where it merges with the magnetosphere; the part of the atmosphere that significantly affects propagation of radio signals on frequencies under 30 MHz

ionospheric storm
- a disturbance in the F-layer of the ionosphere, which occurs in connection with geomagnetic activity causing high absorption of radio signals, cf. geomagnetic storm

IRC
- International Reply Coupon

IRIB
- Islamic Republic of Iran Broadcasting

irr
- irregular; used to express irregular operation or irregular sign-on or
sign-off times of a radio station

ITU
- International Telecommunication Union

 J    to Page Top

jamming
- intentional interference caused to radio signals to prevent the audience from hearing the transmission

JJ
- Japanese language

JRC
- Japan Radio Company

JRTV
- Jordan Radio & Television Corporation

 K   to Page Top

KBC
- Kenya Broadcasting Corporation

KBP
- Kapisanan ng mga Brodkaster ng Pilipinas, Association of Broadcasters of the Philippines

KBS
- Korean Broadcasting System

KCBS
- Korean Central Broadcasting Station

kHz
- abbreviation for kilohertz

kilohertz
- unit of frequency equal to 1000 hertz; LW, MW and SW frequencies are usually expressed in kilohertz

kilowatt
- unit of power equal to 1000 watts; transmitter powers of broadcasting stations are usually expressed in kilowatts, and in watts for very low-power stations

K-Index
- a measure of short-term changes in geomagnetic activity, relative to an assumed quiet-day curve for the recording site, ranging in value between 0 and 9; the mid-latitude K-Index is released every three hours by the US Space Environment Center, one of the dozen stations that produce an aggregate global Kp-Index

kW
- abbreviation for kilowatt

 L   to Page Top

LA
- Latin America(n)

long path
- the longer direct route between any two points on earth; opposite route to short path (great circle path); occasionally radio signals can be received via both paths or only via the long path

longwave (LW)
- if vaguely used can refer to any frequencies below the MW band, but for broadcasting is limited to 153 - 279 kHz, which is used in Europe, the Middle East, Central Asia and Siberia

longwire antenna
- a wire antenna at least two wavelengths long connected to the receiver at one end with the other end pointing to the desired direction of reception; differs from the even more directional beverage antenna because of not being grounded in the opposite end of the receiver

loop antenna
- a small directional antenna consisting of loops of antenna wire forming a round or rectangular figure, normally for use indoors or in limited space, best for MW frequencies

lower sideband (LSB)
- the sideband lower in frequency than the transmitter's carrier

LPAM
- low power AM station; e.g. in the United Kingdom LPAM licenses involve broadcasting with a transmitter power of 1 watt

LPFM
- low power FM (station)

LSB
- lower sideband

LSR
- local sunrise (time)

LSS
- local sunset (time)

LW
- abbreviation for longwave

 M   to Page Top

maximum usable frequency (MUF)
- the highest frequency that allows skywave reception via ionosphere under existing ionospheric conditions

MBC
- Munhwa Broadcasting System

mediumwave (medium wave)
- frequencies 530-1700 kHz (in the Western hemisphere) or 531-1611/1702 kHz (in the Eastern hemisphere), reserved for broadcasting stations (BCB); sometimes used vaguely to refer to any radio signals from 300 to 3000 kHz

megahertz (MHz)
- unit of frequency equal to 1,000,000 hertz or 1000 kilohertz
- equivalent to megacycles, which is an older term

megawatt (MW)
- unit of power equal to 1,000,000 watts

MDR
- Mitteldeutscher Rundfunk

MF
- medium frequencies (300-3000 kHz), includes the mediumwave band

MHz
- megahertz

mode
- the form of radio transmission such as AM, FM or SSB

modulation
- the addition of information to an electronic signal by changing the carrier; common modulation methods include amplitude modulation (AM), frequency modulation (FM) and phase modulation

MR
- Magyar Radio

MUF
- maximum usable frequency

MW
- megawatt
- mediumwave

mx (MX)
- music

 N   to Page Top

Na
- North America
- national anthem (usually NA)

NAB
- National Association of Broadcasters

NBC
- National Broadcasting Company
- the national broadcasting company/corporation of any country

NDR
- Norddeutscher Rundfunk

n.f.
- nominal frequency; the officially assigned frequency that differs from the actual frequency of the station

NHK
- Nippon Hoso Kyokai

noise blanker (NB)
- a receiver circuit that reduces electrical pulse-type noise

NOS
- Nederlandse Omroep Stichting

notch filter
- a receiver circuit that filters a narrow frequency range away from the bandpass to attenuate an unwanted interfering signal with a narrow bandwith

NPR
- National Public Radio

NRK
- Norsk Rikskringkasting

nx (NX)
- news

 O   to Page Top

Oc
- Oceania

Ofcom
- Office of Communications (UK)

OM
- literally an abbreviation for "old man" in friendly reference to any radio operator; nowadays used to refer to any male person on the air

opening
- good propagation conditions to a particular area

ORF
- Österreichischer Rundfunk

ORTAS
- Organisme de la Radio-Télévision Arab Syrienne

overloading
- a situation when a strong signal interferes a weaker signal by creating false signals on interfering frequencies; occurs when the receiver's dynamic range is not enough to deal with the strong signal

 P   to Page Top

pass band shift
- a receiver function that permits shifting the center frequency of the bandpass up or down in frequency to reduce co-channel inteference

path
- the signal route between the transmitter and the receiver, see great circle path, long path

PBC
- Pakistan Broadcasting Corporation

PBS
- Public Broadcasting System
- People's Broadcasting Station (regional or local station in China, e.g. Sichuan People's Broadcasting Station)

PD
- program director (of a radio station)

pirate
- an illegal or unauthorized broadcasting station, usually broadcasting music and operated as a hobby without political motives aside from reducing government control over airwaves, c.f. clandestine

polar-cap absorption (PCA)
- an anomalous condition of the polar ionosphere whereby HF and VHF frequencies are absorbed, and LF and VLF frequencies are reflected at lower altitudes than normally; in practise PCA results from the ionisation of the D-layer of the polar ionosphere by high energy protons (proton flux), so PCAs and proton events are simultaneous; may affect transpolar paths up to days or weeks

polarization
- whether an antenna transmits or receives radio signals best in vertical or horizontal position

PP
- Portuguese language

ppc
- prepared post card, a self-made QSL card sent to the radio station (along with a reception report) to be filled and returned to the sender; doesn't qualify as a QSL is some DXers' clubs

preamp
- a circuit that boosts weak signals while also amplifying noise and interference

preselector
- a circuit that tunes a receiver's signal amplifying circuitry for maximum sensitivity on a desired frequency range.

propagation
- the process of how a radio signal travels from a transmitting station to a receiving station

proton event
- the ionisation of the D-layer of the polar ionosphere by high energy protons, c.f. polar-cap absorption

PSRA
- Presunrise service authorization

PSSA
- Postsunset service authorization

px
- program

 Q   to Page Top

quad
- a directional antenna that consists of two one-wavelength squares of wire placed one quarter-wavelength apart from each other

QRM
- an old abbreviation for man-made interference

QRN
- an old abbreviation for natural interference such as atmospheric noise and lightning static

QSL
- a written message (usually in the form of a card, a letter, an email or a fax) from a radio station to the listener confirming that the listener has indeed heard the radio station; sent in response to a reception report; derived from the old abbreviation for "I confirm/understand"

QTH
- an old abbreviation for location (of the radio transmitter or the listener)

 R   to Page Top

R
- Radio

RAE
- Radiodifusion Argentina al Exterior

RAI
- Radiotelevisione Italiana

RCN
- Radio Cadena Nacional (in Colombia)

Rdiff
- Radiodiffusion

RTP
- Rádio e Televisão de Portugal

REE
- Radio Exterior de España

reception report
- a written message (usually in the form of a letter or an email) from a listener to a radio station containing details of monitored programming in order to receive a QSL in return

rel
- religious

RFE/RL
- Radio Free Europe / Radio Liberty

RF gain
- a receiver control used to reduce the sensitivity of the receiver

RFI
- Radio France Internationale

RFO
- Radio Télévision Française d'Outre Mer

RHC
- Radio Habana Cuba

RN
- Radio Nacional / Rádio Nacional / Radio Nationale

RNA
- Rádio Nacional de Angola

RNE
- Radio Nacional de España

RR
- Russian language

RRI
- Radio Republik Indonesia

RSL
- Restricted Service Licence

RTE
- Radio Telefís Éireann

RTBF
- Radio-Télévision Belge de la Communaute Francaise

RTM
- Radio Television Malaysia
- Radiodiffusion-Télévision Marocaine

rx (RX)
- receiver

 S   to Page Top

SABC
- South African Broadcasting Corporation

SASE
- self-addressed and stamped envelope

SBC
- Swiss Broadcasting Corporation

scanner
- a receiver which automatically scans a range or a sequence of frequencies selected by the listener

SDR
- software-defined receiver / software-defined radio

selectivity
- ability of a receiver to reject signals on frequencies adjacent to the tuned frequency; measured in decibels (dB) at a particular frequency point away from the wanted signal

sensitivity
- ability of a receiver to receive weak signals, measured in microvolts (mV); the lower the number, the more sensitive the receiver is

SER
- Sociedad Española de Radiodifusion

shortwave
- when referring to broadcasting, includes frequencies ranging from 1.7 to 30 MHz (1700 - 30,000 kHz), but sometimes refers also to the HF frequency spectrum from 3 to 30 MHz

sideband
- the portion of a modulated carrier wave that is either above or below the basic signal; the portion above is the upper sideband (USB); the portion below is the lower sideband (LSB); c.f. single sideband

single sideband (SSB)
- a modulation technique that removes one sideband and the carrier and transmits only the remaining sideband; unlike in regular amplitude modulation (AM) transmission in which both sidebands are used to carry a message

SINPO
- a coding system used in reception reports by DXers to international broadcasting stations to indicate the signal strength (S), interference (I), atmospheric noise (N), propagation (P) and overall quality (O) of the reception on a scale from 1 (lowest) to 5 (highest); e.g. SINPO 55555 would be perfect reception - rarely possible on shortwaves

SIO
- a simplified code of SINPO to rate reception quality in reception reports; including values for signal strength (S), interference (I) and overall quality (O)

skip
- a signal route from the transmitter up to the ionosphere and back down to the earth

sky wave propagation
- signals propagated by refraction in the ionosphere, making one or more skips

SLBC
- Sri Lanka Broadcasting Corporation

SM
- station manager (of a radio station)

S-meter
- a meter in a receiver to indicate signal strength

solar activity
- perturbations on the surface of the sun, such as solar flares, which can cause high levels of radiation in space; this radiation can come as plasma (particles) or electromagnetic radiation (light)

solar cycle
- 11-year variation in frequency and number of solar active events; reflected in an 11-year variability of geomagnetic activity; the current solar cycle began in January 2008 and is number 24 since 1755 when tracking began, c.f. solar maximum

solar flux
- unit of radio emission from the sun, used a measured index for solar activity

solar maximum
- the month(s) during the solar cycle when the 12-month mean of monthly average sunspot numbers reaches a maximum; the solar maximum of the ongoing solar cycle (#24) is predicted to be in 2013. Solar cycle #23 peaked in March 2000.

solar minimum
- the month(s) during the solar cycle when the 12-month mean of monthly average sunspot numbers reaches a minimum; the most recent solar minimum (of solar cycle #23) occurred in 2009 and was exceptionally deep

solid state
- a circuit that uses transistors and integrated circuits instead of vacuum tubes

split channel
- a frequency located between standard frequency allocations; e.g. Rádio Nacional de Angola heard regularly on 1367 kHz (between 1359 kHz and 1368 kHz, the latter being the officially assigned frequency for the station)

sporadic-E
- a phenomenon of random areas of ionization occurring in the E-layer of the ionosphere that allows refraction of unusually high frequencies; a phenomenon used by FM DXers for long-distance FM reception

spur
- an additional unintentional signal or frequency as a result of transmitter malfunction

spt (SPT)
- sports

squelch (SQL)
- a circuit in a receiver that mutes the receiver until the signal strength exceeds a predefined level

SS
- Spanish

SSB
- single sideband

sunspot
- an area that appears dark on the photosphere of the sun because it is cooler than the surrounding photosphere; sunspots are concentrations of magnetic flux, typically occurring in bipolar (i.e. two-part with positive and negative poles like a magnet) clusters or groups; a moderate-sized sunspot is about as large as Earth

sunspot number
- a daily index of sunspot activity (R), defined as R = k (10 g + s) where s = number of individual spots, g = number of sunspot groups, and k is an observatory factor

SW
- shortwave

SWL
- shortwave listener

SWLing
- shortwave listening

SWR
- Südwestrundfunk

 T   to Page Top

TC
- time check, time announcement

TDF
- Telediffusion de France

tent
- tentative; used in association with the station name when logging a station without a definite station identification or other proof of the identity of the observed radio station, but when there is reason to believe that it nevertheless was the station mentioned

tlk
- talk (format)

transceiver
- a combined transmitter and receiver

tropical bands
- shortwave bands assigned for broadcasting, mostly in developing countries, covering the following frequency ranges:

  • 2300-2495 kHz - 120-meter band
  • 3200-3400 kHz - 90-meter band
  • 3900-4000 kHz - 75-meter band
  • 4750-5060 kHz - 60-meter band

tropo
- abbreviation for tropospheric ducting

tropospheric ducting
- propagation of frequencies above 30 MHz via bending along weather fronts in the troposphere, the lowest part of the atmosphere; a propagation form used by FM DXers

TRT
- Türkiye Radyo-Televizyon Kurumu

TWR
- Trans World Radio

tx (TX)
- transmitter

 U   to Page Top

UHF
- ultra high frequencies (300-3000 MHz)

unid
- unidentified; used when logging a station which has not been identified (recognized), cf. tent

UNR
- United Nations Radio

USB
- upper sideband

UTC (also UT)
- coordinated universal time

utility stations
- radio stations other than broadcasting or amateur stations; not intended to be heard by the general public, such as marine, air traffic and military communications

 V   to Page Top

v
- variable; used to indicate that the frequency observed is not stable but varies (e.g. 6535v kHz)

VGTRK
- Vserossiyskaya Gosudarstvennaya Teleradiokompaniya, the National Broadcasting Company of the Russian Federation

Vo
- Voice of

VHF
- very high frequencies (30-300 MHz)

VOA
- Voice of America

VOR
- Voice of Russia

VOV
- Voice of Vietnam

v/s
- verification (QSL) signer

 W   to Page Top

wavelength
- the distance between identical points in adjacent cycles of a waveform radio signal; wavelength is inversely related to frequency: the higher the frequency of the signal, the shorter the wavelength
- wavelength and frequency can be counted as follows: divide 300,000 by the frequency in kilohertz and you get the wavelength in meters (e.g. 300,000 : 15,400 kHz = 19,4 meters); conversely divide 300,000 by the frequency in kHz and you get the wavelength in meters

WDR
- Westdeutscher Rundfunk

WRTH
- World Radio TV Handbook

wx
- weather

 X   to Page Top

X-band
- extended mediumwave band; an addition to the traditional MW broadcast band introduced in some countries in the 1990's (1610-1700 kHz in the Western hemisphere, 1611-1702 kHz in the Eastern hemisphere)

 Y   to Page Top

yagi
- a directional antenna type used by FM DXers consisting of a dipole connected to the receiver and two additional elements, a slightly longer reflector and a slightly shorter director; electromagnetic coupling between the elements gives best reception from the direction of the director

YL
- old abbreviation for young lady, used to refer to any female person

YLE
- Yleisradio, the Finnish Broadcasting Company

 other   to Page Top

73
- abbreviation for "best regards"

88
- abbreviation for "love and kisses"

//
- indicates a parallel frequency

 notes   to Page Top
  • the glossary and abbreviations have been chosen based on how important they are to DXers
  • please note that the same terms and abbreviations can have different meanings in other contexts and even in other radio-related hobbies; the definitions listed here apply to DXing
  • internal links to the respective terms appear in italics, links to other pages on DXing.info and to other sites appear in normal font style
  • your corrections and comments are welcome, email info @ dxing dot info
  • for more technical terms, search WhatIs Techtarget
  • for more ham radio terms, check out Amateur radio glossary
  • for more space weather terms, see SEC glossary and IPS glossary
  • for more terms on US radio business, see Radio.About.com glossary
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