Jargon Buster

Like many activities in this world the hobby of radio listening has acquired its own language, or jargon. Some dates back to the earliest days of wireless communications but each generation of technology has spawned its own slang and technical terms.

This is not intended to be a barrier or a private language. It is mostly used for brevity especially where space is limited (for example in loggings tables in Medium Wave News)

In the early days of wireless radio operators generated a a large vocabulary of abbreviations and codes that were easier and quicker to transmit using Morse code than the full phrase they represented. Some of these codes are widely used by radio enthusiasts today, whereas other remain the preserve of those radio amateurs who still operate with Morse code.

73 A short hand code from the earliest days of telegraphy & wireless meaning “best wishes”. Still used by radio enthusiasts today.

A-index A daily index of geomagnetic activity derived as the average of the eight 3-hourly a indices. This A-index has a strong correlation with how MW signals will propagate or travel around the world.

AM Amplitude modulation. The main method of transmitting signals in the long and medium wave bands. Often used in the North America to mean “medium wave”.

AM DX Often used in North America to mean MW DX – see MW DX.

BCB BroadCast Band; An older North American term referring to the MW band.

CW Continuous Wave. But this actually describes a transmission where a continuous carrier is switched on & off to send Morse code characters. Sometimes more loosely applied to any means of transmitting Morse code.

DGPS Differential Global Positioning System – a method transmitting extra information to increase the location accuracy of GPS navigation, uses transmitters around 300kHz

DRM Digital Radio Mondiale. A form of digital modulation being used by some stations in the MW band instead of AM with the potential of high quality, low noise reception. Currently used by a small number of broadcasters.

DX Literally “Distance”. A code from the earliest days of radio meaning a far away signal. Sometimes used to mean anything that is normally difficult to hear with “D” referring to “Difficult”.

DXer A radio hobbyist interested in DXing.

DX-ing The art or activity of listening to distant signals.

DX-pedition An expedition to a location by DXers specifically to listen to DX signals. Usually involves a trip to a site where interference is less or where there is space for advanced aerials.

EMC Electromagnetic Compatibility

FSL Ferrite Sleeved Loop aerial – a modern high performance portable antenna design.

IBOC In Band On Carrier – A proprietary form of hybrid modulation that combines AM and digital modulation on one carrier. mostly used in the USA. IBOC and DRM are not compatible.

ID Identification.

Ionosphere The region of the earth’s upper atmosphere containing a small percentage of free electrons and ions produced by photo-ionization of gas atoms by solar ultraviolet radiation. The ionosphere significantly influences radio wave propagation of MW & LW frequencies.

kHz kilohertz. A unit of measurement of frequency. 1kHz = 1000Hz.

K-index A 3-hourly quasi-logarithmic local index of geomagnetic activity relative to an assumed quiet-day curve for the recording site. Range is from 0 to 9. This is an indicator of how MW signals will propagate or travel around the world.

LF Low Frequencies: 30kHz-300kHz.

LPAM Low Power AM station; radio station intended to cover a small area (e.g a university campus).

Long Wave Refers to the band of frequencies between 148.5 – 283.5kHz used for broadcasting in Europe & Asia.

LW See Long Wave.

MF Medium Frequency A term used to define the radio spectrum between 300kHz and 3000kHz

Medium Wave Refers to the band of frequencies between approximately 520kHz and 1700kHz, though the definition depends on frequency allocations that differ slightly in different parts of the world.

MG Middengolf. Dutch for “Medium Wave”.

MHz Megahertz. A unit of measurement of frequency. 1MHz = 1000kHz = 1,000,000Hz

MW See Medium Wave.

MWC Medium Wave Circle the premier MW DX club in Europe.

MW DX “Long distance medium wave listening” (verb) or “medium wave signals from far away” (noun)

MWN Medium Wave News – journal of the Medium Wave Circle published since 1954.

Navtex A global maritime information service that uses a digital transmission method (SITOR Mode B) on 518 and 490kHz.

NDB Non directional beacon. A radio navigation beacon that mostly operate between 280-500kHz but some are in the MW band. Most continuously transmit a simple callsign in Morse code.

OM Ondes Moyennes. French for “Medium Wave”. Onda Media. Spanish for “Medium Wave”.

QRM An old radio code meaning “interference” from one radio signal degrading reception of another.

QRN An old radio code meaning “noise”. Usually refers to natural noise such as static or thunderstorm noise, but can also mean man-made electrical noise.

QSL A card or letter (or now an e-mail) sent by a station to a listener to confirm that the listener heard the station.

QTH An old abbreviation for location of the radio transmitter (or the listener).

RFI Radio Frequency Interference – i.e. QRM/QRN

SDR Software Defined Radio – a modern radio design that relies on high speed digital processing to perform functions (e.g. filtering and demodulation) that were traditionally performed with analogue circuits.

SSB single side band a form of modulation and demodulation that uses only one sideband, whereas conventional AM uses both upper and lower sidebands.

TDoA Time Delay of Arrival is a technique for radio direction finding that measures the time at which a signal arrives at receivers in different locations.

ULR Ultralight Radio – a modern portable radio that relies on sophisticated digital signal processing for high performance at low cost in a small size.

UTC Coordinated Universal Time is a high-precision atomic time standard which approximately tracks Universal Time (UT). It is the basis for legal civil time all over the Earth: time zones around the world are expressed as positive and negative offsets from UTC. In this role it is also referred to as Zulu time (Z), or using the historical term “Greenwich Mean Time” (GMT).

VLF Very Low Frequencies: 3kHz-30kHz.

X-Band Extended MW 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) Not allocated for broadcasting in Europe or Africa.