Term Meaning Source
30 End of message. ar-wiki
33 Love sealed with friendship and mutual respect between one YL and another YL. (coined by Clara Reger W2RUF, adopted officially by YLRL in 1940) ar-wiki
73 Best Regards (Source: "Morse Code: The Essential Language", 2nd Ed., ARRL Publishing) qrz.com
73 Goodbye, best regards. ar-wiki
88 Love and Kisses ar-wiki
10 code A series of abbreviations (originally 10-1 through 10-29) created by APCO, the US association of public safety communications officers, for use on 1950's-era police radio. As many localities extended the series with their own non-standard codes, the same codes may have different meanings in different agencies (even between police and fire services in the same town). Ten codes are never used in amateur, marine or aviation radio as Q-codes already are in long-established international use but they may be heard in the unlicensed CB radio service and on local public-service frequencies. ar-wiki
11 metres The 27MHz CB general radio service, nominally intended for local communications. As no license or callsign is required to transmit, quality of operating procedure employed on this band may be criticised as variable at best. Where existing citizen's band procedure, code abbreviation and slang terminology are incompatible with amateur radio operating convention, users will find much needs to be re-learned upon leaving 11 metre CB to become licensed radio amateurs. ar-wiki
2, 6, 10, 20, 40, 80, 160 metres See Bands. ar-wiki
807 An old glass vacuum tube, several inches tall and around. Also, slang for a beer, as in "there's nothing like a cold 807 on a hot Arizona afternoon" (thanks to W7QY). According to our friends in Ireland, a pint of Guinness is known as a "Black 807" (thanks to GI4FUE). qrz.com
88 Hugs and/or "Kisses" qrz.com
92 code A series of telegraphic abbreviations devised by Western Union in 1859 (originally as numbers 1 to 92). The later Philips Code added abbreviations for news wire service. While many of the codes are long forgotten, 19 and 31 (absolute and permissive) train orders continue in railroad use, the "30" as used by news editors at the end of a story remains widely known and "73" / "88" greetings are common in amateur radio. ar-wiki
A-Index Linear index for measuring the disturbance level in the earth's magnetic field. The index is defined over a period of one day (Courtesy of IPS Radio and Space Services, Sydney, Australia). qrz.com
A/D Analog-to-Digital dslreports
AC Alternating Current ar-wiki
ACC ACCessory icom
ACSB Amplitude Compandored Sideband modulation qrz.com
Adaptive filter Digital filter associated with Digital Signal Processing. icom
ADC Analogue to Digital Converter. Also known as A/D and A-to-D. A device that samples an analogue wave and converts it into a digital signal, in which a series of numbers is used to represent the amplitude of the original wave. ar-wiki
ADIF Amateur Data Interchange Format, a standard specification for format of exported logbook files. ar-wiki
Adjacent-channel interference When a receiver is tuned to a specific frequency and interference is received on a nearby frequency. icom
Admittance The reciprocal of impedance of a component in a series or parallel tuned circuit. ar-wiki
AF Abbreviation for Audio Frequency. AF is in the range 20Hz to 20 000Hz ar-wiki
AF Audio Frequency icom
AFC Automatic Frequency Control - Automatically compensate frequency drift. icom
AFC Automatic Frequency Control - used to prevent drift in FM receivers ar-wiki
AFC Automatic frequency control. Used in FM receivers to prevent drifting off the received station's frequency. eham.net
AFSK Audio frequency shift keying (as opposed to frequency shift keying, FSK) eham.net
AFSK Audio Frequency Shift Keying, a form of digital signalling. icom
AFSK Audio Frequency Shift Keying. ar-wiki
AGC Automatic Gain Control - a feedback system to reduce fading by automatically adjusting gain ar-wiki
AGC Automatic Gain Control - Automatically optimize receiver amplifier gain. icom
AGC Automatic Gain Control; a circuit in a radio which automatically adjusts the overall gain of the receiver qrz.com
AGC Automatic Gain Control. A feedback voltage in the receiver circuit to prevent fading of a received signal. eham.net
AGL (Height) Above Ground Level, for antenna installations. ar-wiki
ALC Automatic Level Control - a feedback system in the transmitter output amplifier used to prevent overload. ar-wiki
ALC Automatic Level Control - Limits RF drive level to power amplifier during transmit to prevent distortion. icom
ALC Automatic level control. A feedback voltage in the transmitter's output amplifier used to prevent amplifier overload. Also used as feedback from a linear amplifier back to the exciter to prevent overdriving. eham.net
Alternating Current (ac) Electrical current that flows first in one direction in a wire and then in the other. The applied voltage is also changing polarity. This direction reversal continues at a rate that depends on the frequency of the ac. hamuniverse
Alternator A device use to produce alternating current (ac). hamuniverse
AM Amlpitude Modulation ar-wiki
AM Amplitude Modulation icom
AM Amplitude Modulation See: Modulation Modes dslreports
AM Amplitude Modulation; slang often used is "Ancient Modulation" (courtesy of VE3FFK). qrz.com
AM Amplitude Modulation. eham.net
Amateur Satellite A spacecraft dedicated to reception and retransmission of amateur radio signals. hamuniverse
Amateur Television (ATV) Transmitting visual images over the airwaves. Introduction to Slow Scan Television. hamuniverse
Ampere (A) The unit used for measurement of current. Usually abbreviated to Amps ar-wiki
Ampere (A) The basic unit of electrical current. It is measured in amperes. hamuniverse
Amplifier A device that is used to increase voltage, current or power. ar-wiki
Amplifier A device used to increase the output power of a device. icom
Amplitude the height of a wave from the average or median position. ar-wiki
Amplitude Modulation (AM) A method of combining an information signal (modulation) and an RF carrier. Shortwave broadcast stations use this type of modulation, as do stations in the Standard Broadcast Band (535-1705 kHz) AM usually consists of a carrier frequency and 2 sidebands, upper and lower....see Introduction to SSB here. hamuniverse
AMSAT AMateur SATellite icom
AMSAT Radio Amateur Satellite Corporation dslreports
AMSAT The name for amateur radio satellite organizations world-wide, but in particular the Radio Amateur Satellite Corporation. ar-wiki
AMSAT The Radio Amateur Satellite Corporation, non-for-profit corporation dedicated to the advancement of Amateur Radio satellites. hamuniverse
AMTOR A specialised form of RTTY protocol. An acronym for AMateur Teleprinting Over Radio or AMateur Teletype over Radio. ar-wiki
AMTOR Amateur Teleprinter Over Radio, a version of RTTY dslreports
AMTOR AMateur Teleprinting Over Radio - A form of RTTY, radio teletype. icom
AMTOR AMateur Teletype Over Radio. An advanced form of RTTY usually operated on the HF bands. eham.net
AMTOR Automatic Teleprinting Over Radio; popular digital mode on HF qrz.com
analog A signal that varies in a continuous manner as a wave as opposed to a discrete signal such as digital. eham.net
Analog (also analogue) a continuously varying signal. ar-wiki
ANC, ANR Active noise control, active noise reduction. Also referred to as automatic noise cancellation or antinoise on some transceivers. ar-wiki
Anderson power poles Used by many emergency radio operators to connect 12 volts DC to their radios. icom
ANF Automatic Notch Filter icom
ANL Automatic Noise Limiter - Eliminates impulse and static noise peaks. icom
ANT ANTenna icom
antenna a device that intercepts or radiates radio frequency energy dslreports
antenna a device that intercepts or radiates radio frequency energy. eham.net
Antenna a device to either radiate radio signals or to receive them from another station. ar-wiki
Antenna Gain The ratio of the power required at the input of a loss-free reference antenna to the power supplied to the input of the given antenna to produce, in a given direction, the same field strength at the same distance (def. courtesy of Telecom Glossary 2000) qrz.com
Antenna ground system Term used for a RF reference potential for some types of antennas. Most unbalanced or asymmetrical antennas need a good RF ground. icom
Antenna impedance The impedance of an antenna at its resonance. Although an antenna’s impedance fluctuates with the frequency of operation, an antenna should be 50 Ω for most transceivers. icom
Antenna matching When the antenna’s impedance at resonance is at optimum performance for your transmitter output circuit. icom
Antenna Party A long-standing tradition among hams where several gather to assist a fellow ham in mounting antennas and/or towers. Often accompanied by malt consumables and lies AFTER the tower and the antennas are up and working...well, the consumables anyway (thanks to WD5CTQ). qrz.com
Antenna Switch A switch used to change the output of a transceiver from one antenna to another. ar-wiki
Antenna Switch A switch used to connect one transmitter, receiver or transceiver to several different antennas. A two position antenna switch would connect two different antennas. hamuniverse
Antenna Tuner A device that matches the antenna system input impedance to the transmitter, receiver or transceiver output impedance. Also called an antenna-matching network, impedance-matching network or Transmatch. Sometimes called an ATU. How to use an antenna tuner. hamuniverse
Antenna Tuner A device used to match the output impedance of a transmitter to that of an antenna. ar-wiki
antenna tuner device that matches the antenna impedance to the receiver or transceiver output impedance dslreports
Antenna tuner Device used to match an antenna to the output impedance of a transmitter. icom
antenna tuner Impedance-matching device that matches the antenna system input impedance to the transmitter, receiver, or transceiver output impedance. dslreports
antenna tuner Impedance-matching device that matches the impedance of the antenna system input to the transmitter, receiver, or transceiver output impedance. eham.net
Anti-VOX Transceiver circuitry used in voice-operated (VOX) stations to prevent audio from the receiver's speaker from actuating the voice-operated transmitter. ar-wiki
AOS Acquisition of Signal from a satellite; occurs when the satellite becomes "visible" to the antenna as it comes up from the horizon. qrz.com
APC Automatic Power Control - Current limiting of power amplifier to prevent damage to finals in high SWR conditions. icom
APRS Automatic Packet Position Reporting System - See APRS dslreports
APRS Automatic Packet Position Reporting System. eham.net
APRS Automatic Packet Reporting System (Uses GPS + Packet Radio) qrz.com
APRS Automatic Position Reporting System - In conjunction with a GPS and TNC provide position reporting. icom
APRS Automatic Position Reporting System, Automated Packet Reporting System. ar-wiki
ARA Amateur Radio Association dslreports
ARC Amateur Radio Club (also ARA, ARS - Amateur Radio Association, Amateur Radio Society) - usually prefixed by the name of the community or region served ar-wiki
ARC Amateur Radio Club. Military Designation for Avionics (Aviation Radio Composite) dslreports
ARDF Amateur Radio Direction Finding ar-wiki
ARES Amateur Radio Disaster Services, Amateur Radio Emergency Services ar-wiki
ARES Amateur Radio Emergency Service dslreports
ARES Amateur Radio Emergency Service - ARES is a public-service organization of the ARRL. icom
ARES Amateur Radio Emergency Service: sponsored by ARRL, and presents a way for local amateurs to provide emergency communications while working with the Red Cross and Emergency Operations Centers. hamuniverse
ARES Amateur Radio Emergency Service. eham.net
ARISS Amateur Radio on the International Space Station. A program that allows schools, with the help of an amateur club, to contact the amateur station on board the International space station. ar-wiki
ARRL American Radio Relay League dslreports
ARRL American Radio Relay League , the national amateur radio organization in the USA eham.net
ARRL American Radio Relay League; A U.S.-based organization which exists to support Amateur Radio. For more information, please visit http://www.arrl.org. qrz.com
ARRL ARRL - The national association of amateur radio operators. ARRL home page. hamuniverse
ARRL The American Radio Relay League - The National Association for Amateur Radio in the US. icom
ARRL The American Radio Relay League [1]- the national ham radio association for the USA ar-wiki
ASCII American National Standard Code for Information Interchange - A seven-unit digital code for the transmission of teleprinter data. icom
ASCII American Standard Code for Information Interchange. A seven bit code established by ANSI to achieve compatibility between digital devices. eham.net
ASL Above Sea Level. Vertical height in metres or feet above sea level. ar-wiki
ATS Automatic Transfer Switch, switches equipment to a backup power supply in event of power failure. ar-wiki
ATT ATTenuator - A network designed to reduce the amplitude of a signal. icom
Attenuator A resistive device to reduce the amplitude or power of a signal. ar-wiki
ATV Amateur Television - "moving picture" ham TV transmissions. ar-wiki
ATV Amateur Television - FSTV, SSTV icom
ATV Amateur Television; typically found on the 430 MHz and 1.2 GHz bands; see http://www.hampubs.com/atv.htm for more information (thanks to KG4LXA for the suggested link). qrz.com
Auto patch Used in repeater operation for telephone interconnect. icom
Autopatch a device that allows repeater users to make telephone calls through a repeater. hamuniverse
Average power Power measured on standard power meter. icom
AWG American Wire Gauge; a system of describing the diameter of wire by which the wire size increases as the gauge number decreases. qrz.com
Az/El used to describe an antenna rotator that can change both the Azimuth (horizontal) and the Elevation (vertical) direction of the antenna. ar-wiki
Azimuth The horizontal direction (angle) measured clockwise from North. ar-wiki
Backscatter Radio signals reflected back from ionized patches in the ionosphere. icom
Backstay Rigging to support the mast in maritime mobile installations, usually insulated for HF antenna purposes. icom
balanced line A feed line with two conductors having equal but opposite voltages, with neither conductor at ground potential dslreports
Balanced Line parallel conductors at equal and opposite potentials. Neither conductor is at ground potential. ar-wiki
Balun A passive electronic device that converts between balanced and unbalanced electrical signals using some form of electromagnetic coupling. ar-wiki
Balun A simple transformer used to change an unbalanced input to a balanced output. icom
balun balance to unbalance, a device used to couple a balanced antenna to an unbalanced feed line dslreports
balun balanced to unbalanced. A device used to couple a balanced antenna to an unbalanced feed line (e.g., dipole to coax) . eham.net
band a range of frequencies allotted for a particular use dslreports
band a range of frequencies allotted for a particular use (e.g., 20 Meter Band) eham.net
Band A range of frequencies. icom
Band The portions of the Electromagnetic Spectrum that are allocated to ham radio operators. ar-wiki
Band Plan Agreements between operators about how to use the band/s, rather than FCC regulations. Portions of each ham band are dedicated to certain modes of operation. See ARRL Band Plan here. hamuniverse
Band-Pass Filter A circuit that allows signals to go through it only if they are within a certain range of frequencies. It attenuates signals above and below this range. hamuniverse
band-pass filter a circuit that passes a range of frequencies and attenuates signals above and below this range. eham.net
bandpass range of frequencies permitted to pass through a filter or receiver circuit. eham.net
Bandpass (also Passband) the range of frequencies that a certain filter allows to pass. ar-wiki
Bandpass Filter a filter designed to pass a certain range of frequencies. ar-wiki
Bandwidth Frequency needed for particular type of emission. icom
Bank Memory bank icom
Barefoot Refers to running your transmitter without an amplifier (in other words, the "power out" is being produced entirely by the transmitter, without any assistance from an amplifier). qrz.com
barefoot transmitting with a transceiver alone and no linear amplifier dslreports
barefoot transmitting with a transceiver alone without a linear amplifier. eham.net
base a radio station located at a fixed location as opposed to a mobile. Used to identify the control location in a network of radio stations. eham.net
Base Station A ham station that has a fixed location ar-wiki
baud A unit of signaling speed equal to the number of discrete signal events per second. Baud is the same as BPS only if each signal event represents exactly one bit. eham.net
Baud The rate of transmission - in symbols per second, of digital data. The number of times a transmitted digital signal changes per second. In the one special case where data is transmitted one bit at a time serially, the baud rate will match the bps rate. ar-wiki
Baudot A five level code for the transmission of data in digital form. eham.net
BBS Bulletin Board System. An automated computer system which can be controlled from a remote location. Usually capable of sending and receiving messages and files. eham.net
BCI BroadCast Interference icom
beacon a station that transmits one-way signals for the purpose of navigation, homing, and determining propagation conditions. eham.net
beacon A station that transmits one-way signals for the purpose of navigation, homing, and propagation condition determination dslreports
Beacon A station that transmits signals either continuously or on a timed basis, for location and propagation purposes. ar-wiki
Beacon Station An amateur station transmitting communications for the purposes of observation of propagation and reception or other related experimental activities. hamuniverse
Beacons Ham radio signals used for propagation study, found on specific frequencies. icom
beam an antenna that gives a directional beam pattern. Also called a Yagi. eham.net
BFO Beat Frequency Oscillator qrz.com
BFO Beat Frequency Oscillator. An oscillator that is mixed with an incoming signal at the detector to produce an Audio Frequency (AF) tone for CW reception. In SSB operation, the beat frequency oscillator must replace the carrier which was suppressed when the signal was originally transmitted. ar-wiki
BFO Beat frequency oscillator. Used to mix with the incoming signal to produce an audio tone for CW reception dslreports
Bird 1. nickname for "satellite", in the case of Amateur Radio, examples include RS-12/13 (Radio Sputnik) and AO-40 (AMSAT-OSCAR). See http://www.amsat.org/amsat/sats/n7hpr/satsum.html and http://www.hampubs.com/satellite . 2. brand name of a high-end, high quality directional wattmeter. qrz.com
Bird Slang term for an amateur or communications satellite. ar-wiki
Birdie A signal produced within a radio, typically by it's microprocessor or related circuitry, that appears at specific intervals across the tuning dial of a receiver. Usually it is a product of mixed intermediate frequencies within the radio. Considered bad form. qrz.com
Block Diagram A drawing using boxes to represent sections of a complicated device or process. hamuniverse
BNC A push-and-turn locking coaxial connector commonly used with VHF/UHF transceivers, as well as oscilloscopes and test equipment. ar-wiki
BNC Bayonet Neill-Concelman - A type of antenna connector. icom
BNC Coax connector commonly used with VHF/UHF equipment dslreports
BNC Coax connector commonly used with VHF/UHF equipment -- Bayonet Niell-Concelman (standard connector type used on COAX cable, named for its inventors). eham.net
Boat Anchor A slang term used to describe obsolete ham radio gear - often applied to old transceivers. ar-wiki
boat anchor antique ham equipment dslreports
Boat Anchor Slang for a large, heavy, usually old radio, typically restored (courtesy of VE3FFK). qrz.com
BPF BandPass Filter icom
BPL BroadBand Over Power Lines dslreports
bps Bits per second dslreports
BPS Bits per second, the rate at which digital data is transmitted. The number of characters transmitted per second will be a sub-multiple of this figure (for instance, if a character is sent with 8 data bits, 1 start bit, 1 stop bit, the number of actual characters transmitted per second would be one tenth the bps rate). ar-wiki
BPS Bits per second. A rate of data transfer. eham.net
BPSK (Binary Phase Shift Keying). A digital modulation method for transmitting data. ar-wiki
BPSK Binary Phase Shift Keying, digital DSB suppressed carrier modulation dslreports
BPSK Binary Phase Shift Keying; a modulation technique used in LowFER and MedFER operation, as well as HF operation. For more information, see http://www.computerpro.com/~lyle/watsbpsk.htm (courtesy of K?LR). qrz.com
BPSK Binary Phase Shift Keying. Digital DSB suppressed carrier modulation. eham.net
Brass Pounder Refers to someone who sends telegraphy by old fashioned "straight" key, i.e., without any keyers, etc., or paddles. qrz.com
Buffer Amplifier An amplifier usually attached to an oscillator so as to reduce the drain on the oscillator output. ar-wiki
Bug A mechanical keying device for transmitting Morse Code semi-automatically. qrz.com
bug a semi-automatic mechanical code key. eham.net
Bunny hunt Finding hidden transmitters, sometimes called "T HUNTING" and "Fox Hunting." icom
bureau International Amateur organizations set up to process QSL cards between countries. Provides an inexpensive way to send and receive QSL cards. eham.net
Bureau (also Burro) An organization set up to process QSL cards between amateurs. ar-wiki
Bureau or Buro See "QSL Bureau" qrz.com
burro Slang for bureau. eham.net
Busy lockout Inhibits transmit on a frequency in use. icom
call book a publication or CD ROM that lists licensed amateur radio operators. eham.net
Call sign Sequence of letter and numbers used to identify amateur radio operators and issued by the countries licensing bureau. icom
calling frequency A standard frequency where stations attempt to contact each other dslreports
calling frequency A standard frequency where stations attempt to contact each other. Example -- 146.52 is the North American FM simplex calling frequency. eham.net
Callsign A unique identifier for each radio amateur and licensed radio station throughout the world ar-wiki
CAP Civil Air Patrol - Volunteer affiliate of the United States Air Force. icom
Capacitive Hat Also known as a capacity hat. A system of wires, or at VHF and above a solid metal disk, added to the top of a vertical antenna to reduce its inductance and increase its bandwidth. ar-wiki
Capacitor A passive electronic component composed of two conducting plates separated by a dielectric (insulating material). ar-wiki
capacitor an electronic component composed of two or more conductive plates separated by an insulating material. A capacitor stores energy in an electric field dslreports
Capacitor An electrical component usually formed by separating two conductive plates with an insulating material. A capacitor stores energy in an electric filed. Old terminology, use the word condenser. hamuniverse
Capture effect Only the strongest signal heard over an FM receiver. icom
carrier a pure continuous radio emission at a fixed frequency, without modulation dslreports
carrier a pure continuous radio emission at a fixed frequency, without modulation and without interruption. Several types of modulation can be applied to the carrier, See AM and FM. eham.net
Carrier An unmodulated transmitted signal. icom
Carrier Frequency The centre frequency of a radio signal. ar-wiki
Carrier frequency offset Carrier Shift - Distance between mark and space of the carrier for RTTY or similar communications. icom
Carrier Power The average power supplied to the antenna when no modulation is taking place. ar-wiki
Cavity filter A very narrow RF filter used to pass one single frequency, common in repeater operations where the receiver must be protected from overload by a transmitter on the same band on the same antenna tower. ar-wiki
CBA Call Book Address qrz.com
CBR Cross Band Repeater - A repeater which receive incoming signal and retransmit it in different bands— e.g. receives 144 MHz bands and re-transmits 430(440) MHz bands. icom
CC&R's Covenants, Conditions, and Restrictions - an extensive set of rules drawn up by homeowner's associations and their lawyers which, among other things, typically restrict or completely prohibit a homeowner from having most forms of antennas on their property. eham.net
CC&R's Covenents, Conditions, and Restrictions dslreports
CC&R's Covenents, Conditions, and Restrictions; an extensive set of rules drawn up by homeowner's associations and their lawyers which, among other things, typically restrict or completely prohibit a homeowner from having most forms of antennas on his/her property. Such regulations are formed and placed upon the property before the home is initially sold, and typically remains in effect for the life of the home. qrz.com
CCW Counter ClockWise icom
Centi The metric prefix for 10(-2), or divided by 100. hamuniverse
CG See "Call Guard" (Also CTCSS) qrz.com
CH CHannel - Sequence of memory positions where frequency and related information is stored. icom
Channel Guard General Electric's trademarked name for CTCSS. (RCA called it Quiet Channel, or QC) qrz.com
chassis ground the common connection for all parts of a circuit that connect to the negative side of the power supply dslreports
CI-V Icom computer Control Interface allows multiple radio control simultaneously. icom
Circular Polarization A method of polarizing the antenna such that the emmitted electric field rotates around the axis of the antenna ar-wiki
Clipping Overdriving an amplifier circuit, causing the signal to drop out on voice peaks. (AKA: Flat topping a signal) icom
Closed Repeater A repeater that is restricted in use to only those authorized by a club or group. hamuniverse
Closed, or Complete Circuit An electrical circuit with an uninterrupted path for the current to follow. Turning a switch on, for example, closes or completes the circuit, allowing current to flow. hamuniverse
CLOVER A PSK mode that allows full duplex communications. ar-wiki
CNDX Abbreviation for Conditions ar-wiki
coax A type of wire that consists of a center wire surrounded by insulation and a grounded shield dslreports
Coax Coaxial cable; RF transmission line; used to connect an antenna to a radio; "coaxial" indicates that the conductors are about the same axis, with a center conductor being on that axis, and the "shield" wrapped around the axis (dielectric separates the center conductor and the shield wires). qrz.com
coax ( coaxial cable) A type of wire that consists of a center wire surrounded by insulation and then a grounded shield of braided wire. The shield minimizes electrical and radio frequency interference. 50-ohm and 72 ohm characteristic impedances are typical. eham.net
Coaxial Cable Cable that has a central conductor and an outer shield as the second conductor. Known as coaxial because the cable is cylindrical and the conductors share the same central axis. ar-wiki
code usually refers to Morse code, but used for others such as baudot dslreports
code usually refers to Morse code, but used for others such as baudot. eham.net
coil a conductor wound into a series of loops dslreports
Color Code Also spelt colour code. Coloured bands on resistors and other components that show their value. ar-wiki
color code Colored stripes painted on the body of resistors and other components to show value dslreports
Condenser old name for Capacitor ar-wiki
condenser old term for capacitor composed of two or more conductive plates separated by an insulating material to store energy in an electric field dslreports
Conductor A material that has a loose grip on its electrons, so an electrical current can pass through it. Wire is a condcuctor of electricity. hamuniverse
Conductor A material through which electricity flows easily. ar-wiki
Contesting Working as many stations as you can over a specific amount of time. icom
Control Operator Am amateur operator designated by the licensee of a station to be responsible for the transmissions of an amateur station. Many control operators are sometimes used in large repeater systems. You are the control operator of your licensed call sign. hamuniverse
control operator the Amateur Radio operator designated to "control" the operation of the repeater, as required by FCC regulations dslreports
Controlled Environment Any area in which an RF signal may cause radiation exposure to people who are aware of the radiated electric and magnetic fields and who can exercise some control over their exposure to these fields. The FCC generally considers amateur operators to be in a controlled RF exposure environment to determine the maximum permissible exposure levels. hamuniverse
Conversion Number of IF circuits in the receiver. icom
core the material used in the center of an inductor coil, where magnetic fields is concentrated dslreports
Core The material used in the centre of an Inductor coil. ar-wiki
Coronal hole Sunspot activity that may lead to enhanced VHF and 10 meter propagation. icom
CPU Central Processing Unit icom
CQ calling any amateur radio station, may be sent in CW, phone or some digital modes eham.net
CQ CQ?"Calling any station" - the general call when requesting a conversation with anyone. hamuniverse
CQ Radio communications term used to call others. icom
CQ Request for contact - specifically "calling any operator" ar-wiki
CQ Magazine Published by CQ Communications. ar-wiki
Cross Modulation distortion caused by two or more carriers interfering with each other. ar-wiki
Crossband repeat A mode in many dual band radios where a radio transmits on one band, a crossband repeater transmits the received signal on another band, which is heard back by the radio on the other band. icom
CRRL Canadian Radio Relay League now called Radio Amateurs of Canada (RAC). eham.net
Crystal Oscillator A circuit that uses a quartz crystal to keep the frequency of a transmitter constant or within certain limits as related to it's frequency. hamuniverse
Crystal-Controlled Transmitter A simple type of transmitter that consists of a crystal oscillator followed by driver and power amplifier stages. hamuniverse
CSCE Certificate of Successful Completion of Examination (U.S.) issued when amateur radio license examinations passed dslreports
CTCSS (Repeater Term) abbreviation for continuous tone-controlled squelch system, a series of subaudible tones that some repeaters use to restrict access. eham.net
CTCSS abbreviation for continuous tone-controlled squelch system dslreports
CTCSS Continuous Tone Coded Squelch System - Adds a continuous sub-audible low frequency tone to the transmitted carrier. Receivers set for the same low frequency tone can decode signal to hear the audio. icom
CTCSS Continuous Tone-Coded Squelch System - a sub-audible tone that is frequently used on repeaters. The signal "opens" the repeater for use. ar-wiki
CTCSS Continuous Tone-Coded Squelch System, also known as "PL" ("Private Line", trademarked term by Motorola), "Call Guard" (trademarked by GE), or "subaudible tone". A means of transmitting a tone along with your signal. This tone tells a receiver to open up its squelch so that the signal is received. This method is commonly used with repeaters. qrz.com
CTCSS Continuous tone-coded squelch system, used to limit repeater interference. Also called PL tones, taken from Motorola "Private Line" system terminology. hamuniverse
current a flow of electrons in an electrical circuit dslreports
Current A flow of electrons in an electrical circuit. Measured in Amps or parts of an amp. hamuniverse
Current The flow of electricity through a conductor - usually associated with electron movement, but current is actually the transfer of charge between atoms. ar-wiki
CW 1) Carrier Wave - 2) ClockWise icom
CW Continuous Wave - used in Morse code transmissions. ar-wiki
CW Continuous Wave, an unmodulated, uninterrupted RF wave used with Morse code dslreports
CW Continuous Wave, see carrier. In truth a continuous wave is an unmodulated, uninterrupted RF wave. However in common usage refers to Morse code emissions or messages which is an interrupted wave. eham.net
CW Continuous Wave; popular digital mode on HF which utilizes Morse Code; regarded by many as the *first* digital mode. qrz.com
CW (Morse code) A communications mode transmitted by on/off keying of a radio-frequency signal. hamuniverse
CW Abbreviations Used by CW operators to reduce the length of transmissions by shortening words or phrases to a 2 or three letter code. ar-wiki
CW filter Used to narrow the IF passband to improve reception selectivity in crowded band conditions. icom
cycles (cps) term used for measuring frequency prior to the term Hertz replaced it hence kc, Mc, etc. eham.net
D region The lowest region of the ionosphere. The D region contributes very little to the short-wave radio propagation. It acts mainly to absorb energy from radio waves as they pass through it. This absorption has significant effect of signals below about 7.5 MHz during daylight. hamuniverse
D-RATS Multi-platform integrated tool for communicating digital information, developed for First Responders, using D-STAR radios. icom
D-STAR Digital Smart Technologies for Amateur Radio, an open protocol. icom
DAC Also known as D/A and D-to-A. Digital to Analogue converter. A device that converts digital signals into analouge signals. ar-wiki
Data Computer communications modes, often called digital communications because digital computers are used. hamuniverse
Data communications Transfer of data between two or more locations. icom
dB Decibel - the ratio of two power measurements. ar-wiki
dB Decibel (1/10 of a Bel); unit for the ratio of two power measurements dslreports
dBd dB relative to a dipole. Also known as dBD ar-wiki
dBd Unit of RF power as compared to an ideal half wave dipole antenna. icom
dBi dB relative to a theoretical isotropic (point) source. ar-wiki
dBi Unit of RF power as compared to an isotropic antenna. icom
dBm Decibels measure, 1 mW with a load impedance of 600 Ω (0 dBm=1 mW). icom
dBm The power compared to a 1 milliwatt (1mW) source, expressed in decibels (dB) ar-wiki
dBo Optical gain. An unofficial term used by some amateurs working with transmission of data using light. ar-wiki
dBuv a measure of voltage compared to one microvolt. 0dBuv = one microvolt. ar-wiki
DC Direct Current icom
DC ground A connection point directly to chassis or battery ground to prevent build-up of hazardous DC voltages. icom
DCS Digital Coded Squelch qrz.com
DCS Digital Coded Squelch, a method of silencing radios until a specific string of tones are received to open the audio stage. An alternate to CTCSS. icom
DE From in CW-speak qrz.com
de Morse code for "from" e.g., AC6V de WA0PPP dslreports
De or DE this is or "from" - for example an operator may use VL2TK de VK4ZW ....... ar-wiki
Deci The metric prefix for 10(-1), or dividing by 10. hamuniverse
demodulation the process of retrieving data from a modulated signal. (See modulation, modem.) eham.net
Detector The stage in a receiver in which the modulation (voice or other information) is recovered from the RF signal. hamuniverse
Deviation A measurement for an FM signal for the maximum frequency changes on either side of the carrier frequency. icom
Deviation The resultant frequency swing of a signal that is frequency modulated (FM). qrz.com
DF Direction finding. Also known as ARDF and "fox hunting", the use of triangulation and directional antennas to find a hidden transmitter. May be done recreationally, or as a means of locating the source of problematic radio frequency interference. ar-wiki
Dielectric A non-conductive material used to separate the center conductor and shield (conductor) in coaxial cable; typically made of foam or plastic. qrz.com
digipeater A simplex packet repeater which stores an incoming packet, and, if so instructed, re-transmits it. The digipeater does not retain a copy of the packet once sent or wait for an acknowledgement from the next node. eham.net
digital A discrete or discontinuous signal whose various states are identified with specified values. (See analog, RS-232, 7'TL.) eham.net
Digital Computer based communications. hamuniverse
Digital communications Information sent digitally, which may be decoded as voice, data, and/or video. icom
diplexer A frequency splitting and isolation device to couple two transceivers to a single or dual band antenna dslreports
Diplexer A frequency splitting device used to couple two transceivers to either a single antenna or a dual band antenna. ar-wiki
dipole the basic antenna consisting of a length of wire or tubing, open and fed at the center. The entire antenna is ½ wavelength long at the desired operating frequency. This antenna often used as a standard for calculating gain, dBd. eham.net
Dipole A half wave antenna, with a bi-directional radiation pattern. icom
Dipole An antenna with two collinear elements, usually of equal length, with feedpoint in the centre. Commonly used as the driven elements for more complex antennas such as the yagi or log-periodic, a dipole on its own is omnidirectional if mounted for vertical polarisation but has a figure-8 directional pattern if mounted horizontally. ar-wiki
Dipole Likely the most common wire antenna amongst hams, the easy-to-homebrew dipole consists of two legs (each 1/4 wavelength) which typically extend horizontally and away from each other. One leg connects to the coax's center conductor, and the other leg connects to the coax's shield as a counterpoise. The dipole antenna is usually strung in a horizontal fashion between trees, and works best when at least 1/4 wavelength above the earth. qrz.com
dipole the basic wavelength antenna consisting of a length of wire or tubing, open and fed at the center dslreports
Direct Current (dc) Electrical current that flows in one direction only. Batteries use direct current. hamuniverse
Dish A highly directional antenna, parabolic in shape. Often used at microwave frequencies. ar-wiki
Distress call Signals a life-threatening situation. Most commonly referred to as an SOS or MAYDAY call. icom
Distress frequency A frequency or channel specific for use in distress calling. Radiotelephone distress frequencies are 2.182 MHz and 156.8 MHz. Survival craft use 243 MHz. Maritime distress frequencies are the same, while general aviation frequencies are 121.5 MHz. icom
Domino EX a digital mode that uses a variant of MFSK known as IFK for transmission of information. ar-wiki
Doppler shift Common in satellite communications, where signals may very up or down in frequency, as the satellite approaches and departs from view. icom
Downconverter A device to take higher frequencies, and lower them to appear at a lower frequency, for reception. icom
Downlink [vs. Uplink] Frequency that repeater or satellite transmits on to a user. icom
downlink Channel used for satellite-to-earth communications dslreports
Downlink The channel or frequency used for satellite to earth communications. ar-wiki
DPSK Differential Phase Shift Keying - a form of BPSK ar-wiki
DPSK Differential Phase Shift Keying, a form of BPSK dslreports
DR A CW abbreviation for "dear", used as a respectful salutation. Example "GOOD EVENING, DR JOHN, HW ARE U?" qrz.com
Driven Element An "arm" of a yagi antenna to which RF power is fed from the coax. qrz.com
DRM Digital Radio Mondiale. A system of digital broadcasting developed by a consortium of manufacturers, researchers, broadcasters and governments. ar-wiki
DSP Digital Signal Processing - allows for filtering, noise reduction, audio equalization, etc. dslreports
DSP Digital Signal Processing. The digital processing of signals in filtering, noise reduction etc. ar-wiki
DSP Digital Signal Processor - Used to improve the signal to noise ratio for clearer and more legible communications. Relatively new to the ham radio. icom
DSP feature reduces unwanted signal noise icom
DSSB Double Suppressed Sideband modulation qrz.com
DSW Russian abbreviation for "goodbye" on CW. qrz.com
DTCS Digital Tone Coded Squelch - A Selective call system. icom
DTMF abbreviation for dual-tone multi-frequency, the series of tones generated from a keypad dslreports
DTMF Dual Tone Multi Frequency - the allocation of a unique tone pair to each button on an appliance (made up of two frequencies - high and low) that allows a computer to recognize the tone. Originally used on a wide scale in landline telephony to allow tone dialling using a small keypad on a telephone or handset, but has been used in amateur radio to remotely control repeaters, autopatch, IRLP or Echolink nodes. ar-wiki
DTMF Dual Tone Multi-Frequency [touch-tone] - Used for transmit/receive numeric information such as phone number, PIN, remote radio control commands, etc. icom
DTMF Dual Tone, Multiple Frequency; a tone that is actually comprised of two different tones sounded at the same time. It is what you hear when you use the pushbuttons on a standard non-pulse telephone in the U.S. It is also a common way to send analog numeric information, since each numeral between ? and 9 has its own separate tone (and also # and *, and in the case of some radios, A, B, C, and D). qrz.com
Dual Band Antenna An antenna designed to be used on two amateur Bands. ar-wiki
Dual-Band Antenna An antenna designed for use on two different Amateur Radio bands. hamuniverse
dual-band antenna antenna designed for use on two different Amateur Radio bands dslreports
Dualwatch Receiving two signals simultaneously. icom
Dummy Antenna A device for transmitter testing or adjusting that allows a signal to be generated but not transmitted over the air. Also called a dummy load. hamuniverse
dummy load a device which substitutes for an antenna during tests dslreports
dummy load a device which substitutes for an antenna during tests on a transmitter. It converts radio energy to heat instead of radiating energy. Offers a match to the transmitter output impedance. eham.net
Dummy load A non radiating 50 Ω load connected to the transmitter to replace the antenna for testing purposes. icom
Dummy Load An artificial antenna that does not radiate. A non-inductive power resistor, a dummy load is connected in place of the transmitting antenna and used when aligning transceivers. ar-wiki
Dummy Load Typically a power dissipating resistor or device substituted in place of an antenna on a transmitter, used for testing purposes. qrz.com
Duplex An operation mode in which the transmit and receive frequencies are different. icom
duplex mode in which a radio transmits on one frequency and receives on another dslreports
Duplex Transmit and receive are on two different frequencies - often use in repeaters with a shift (difference) of 600Hz. ar-wiki
Duplex Transmitting on one band or frequency while receiving on another. Such as a ham radio repeater system. More hamuniverse
Duplexer A device that allows a dual-band radio to use a single dual-band antenna. hamuniverse
Duplexer A device that allows an antenna to transmit and receive simultaneously. ar-wiki
Duplexer A device which divides transmit and receive signals. icom
duplexer device which allows a single antenna to transmit and receive simultaneously dslreports
Duty Cycle A measure of the amount of time a transmitter is operating at full output power during a single transmission. A low duty cycle means less RF radiation exposure for the same PEP output. Continuous key down of an am signal would be considered 100% duty cycle. hamuniverse
Duty cycle The ratios of transmit to receive time. icom
DVM Digital voltmeter dslreports
DVM Digital voltmeter. ar-wiki
DX a distant station or to contact a distant station dslreports
DX Distance or distant station. Originally "distant exchange", from landline telephony. On HF radio, normally used to refer to a station on another continent or in an exotic location. ar-wiki
DX Long distance; making contacts over long distances. For HF contacts, "DX" is typically considered as such if the station contacted is outside of your country. In some other cases, making a contact over what is considered extremely long distances (for the conditions and band) can be considered "DX" (i.e., a QSO from one end of a state to another, on 2 meters simplex, can be considered "'DX"). qrz.com
DX Distance, foreign countries. Stations outside your country boundries. hamuniverse
DXCC award for contacting and confirming 100 or more different countries dslreports
DXCC Award offered by ARRL for contacting and confirming 100 or more different countries first introduced in 1937. DXCC is copyright ARRL and its use here is printed with permission of the ARRL. eham.net
DXCC DX Century Club ar-wiki
DXCC DX Century Club. An ARRL-sponsored club by which membership is allowed only after showing proof of having made contact with at least 100 different countries. For more information, please see http://www.arrl.org. qrz.com
DXpedition An expedition by amateurs to a location that may be geographically or physically remote and from where amateur contacts are rare. ar-wiki
DXpedition Derived from the words "DX" and "expedition", this term typically refers to a trip made by experienced ham operator(s) to a "DX" country for the purpose of providing other hams an opportunity to make a contact (QSO) into that country. qrz.com
DXpedition Radio expedition to remote and rare locations eham.net
DXpedition Trip to foreign land or rare entity to operate ham radio. icom
dynamic range How well a receiver can handle strong signals with overloading; any measure of over 100 decibels is considered excellent dslreports
Dynamic Range How well a receiver can handle very strong signals wthout overloading. ar-wiki
E LAYER The ionospheric layer usually responsible for most 10 meter and 6 meter skywaves over 1500 mile paths. Appears especially in summer season. icom
E region The second lowest ionospheric region, the E region exists only during the day. Under certain conditions, it may refract radio waves enough to return them to Earth. hamuniverse
E-Skip Propagation through signals being refracted in the E-Layer ar-wiki
Earth A circuit connection to a ground rod driven into the ground or system of wires buried below the surface of the ground. ar-wiki
earth ground a circuit connection to a ground rod driven into the earth dslreports
Earth-Moon-Earth (EME) or Moonbounce A method of communicating with others stations by reflecting radio signals off the Moon?s surface. hamuniverse
EBS Emergency Broadcast System - A system where at first an attention tone is transmitted over all station ad the second tone followed with specific instruction regarding the receivable frequency in the national emergency. icom
EEPROM Electrically Erasable and Programmable Read Only Memory icom
EHF Extremely High Frequency - from 30GHz to 300GHz ar-wiki
EIRP Effective Isotropic Radiated Power. The sum of transmitted power and antenna gain, minus any transmission line losses. ar-wiki
Electromagnetic Spectrum A graphic representation of a range of frequencies from 60 Hz electrical current, through radio waves, visible light, ultra violet light, X-rays and Gamma rays. hamuniverse
Electromagnetic Waves The waves emitted by an antenna, having two dimensions, electric and magnetic. ar-wiki
Electromotive Force (EMF) The force or pressure that pushes a current through a circuit. hamuniverse
Electron A tiny, negatively charged particle, normally found in an area surrounding the nucleus of an atom. Moving electrons make up an electrical current. hamuniverse
Electron Tube (Also known as an Vacuum Tube or a Thermionic Valve). A device that creates or modifies an electrical signal through the movement of electrons in a low pressure (vacuum) space. ar-wiki
Elevation (1) The angle that an antenna - often a beam - makes with the horizontal. ar-wiki
Elevation (2) How high an object/place/station is above sea level. Same as ASL (Above Sea Level) ar-wiki
eleven meters currently the CB band, once a Ham band dslreports
elmer a mentor; an experienced operator who tutors newer operators dslreports
Elmer Slang for a person who helps newcomers get started in amateur radio. ar-wiki
EME Earth Moon Earth - bouncing a signal off the moon to a remote station that would not normally be accessible. ar-wiki
EME Earth Moon Earth, also known as moon bounce, is a radio technique where amateur radio operators operate via reflected signals from the Moon. Making a signal path from an earth bound station, reflected off the moon, back to another earth bound station. icom
EME Earth-Moon-Earth communication; moonbounce; using the moon as a reflector to "bounce" your signal back down to Earth. For a complete resource, please see http://www.nitehawk.com/rasmit/ws1_1.html qrz.com
EME Earth-Moon-Earth; using the moon as a reflector for a signal path; moonbounce dslreports
Emergency A situation where there is a danger to lives or property. hamuniverse
Emergency Traffic Messages with life and death urgency or requests for medical help and supplies that leave an area shortly after an emergency. hamuniverse
Emergency Traffic Messages with life or death urgency or requests for medical help and supplies that leave an area shortly after an emergency. hamuniverse
EMF Electromotive Force - Voltage. ar-wiki
EMF Electromotive force; voltage dslreports
EMI Electromagnetic interference dslreports
EMI Electromagnetic Interference, sometimes caused by battery chargers and inverters. icom
EMI Electromagnetic Interference. ar-wiki
Emission The transmitted signal from an amateur station. hamuniverse
Emission Transmission of a signal icom
emission mode the form of a radio emission, such as AM, FM, or single sideband dslreports
EMR Electromagnetic Radiation hamuniverse
Energy The ability to do work; the ability to exert a force to move some object. hamuniverse
eQSL Electronic QSL - a website for sending and receiving QSL's online. ar-wiki
ERP Effective Radiated Power dslreports
ERP Effective Radiated Power; the power supplied to an antenna multiplied by the antenna gain in a given direction (if the direction is not specified, the direction of maximum gain is assumed). qrz.com
ERP Effective Radiated Power. ar-wiki
ERP ERP - Effecive Radiated Power - In radio telecommunications, effective radiated power or equivalent radiated power (ERP) is a standardized theoretical measurement of radio frequency (RF) energy using the unit watts, and is determined by subtracting system losses and adding system gains. ERP takes into consideration transmitter power output (TPO), transmission line attenuation (electrical resistance and RF radiation), RF connector insertion losses, and antenna directivity, but not height above average terrain (HAAT). ERP is typically applied to antenna systems. (Definition from Wikipedia). See ERP chart examples here! hamuniverse
ether Old theory for the medium once believed to conduct radio waves dslreports
Eu Europe ar-wiki
Eyeball Face-to-face meeting, as in "eyeball QSO" (to speak to one another in person). qrz.com
F CONNECTOR Found on 440 MHz and 1.2 GHz antenna circuits. icom
F region A combination of the two highest ionospheric regions, the F1 and F2 regions. The F region refracts radio waves and returns them to Earth. Its height varies greatly depending on the time of day, season of the year and amount of sunspot activity. hamuniverse
F/D The ratio of focal length to diameter of a parabolic dish antenna. ar-wiki
Fading Signal reduction due to atmospherics. icom
FB Fine Business; cheerful acknowledgement, or adjective for describing a good quality. qrz.com
FCC Federal Communications Commission, US governmental body that regulates the radio spectrum dslreports
FCC Federal Communications Commission. The US government body that regulates the use of the radio spectrum. ar-wiki
Feed Line The wires or cables used to connect a transmitter, receiver or transceiver to an antenna. Technicial characteristics of coaxial cable feed line here. hamuniverse
Feed point Where the coaxial cable or ladder line joins the active antenna. icom
Feedline The wire or cable that joins a transmitter or receiver to an antenna. Also known as a transmission line. ar-wiki
feedline wire or cable connecting a radio to an antenna dslreports
FET Field-effect transistor dslreports
FET Field-effect transistor, a semiconductor in which current between source and drain is controlled by voltage applied to a high-impedance gate ar-wiki
Field Day A once a year contest sponsored by the ARRL where hams go to remote sites and operate for 24 hours. Used to assist hams in emergency preparedness as well and to practice not sleeping, treating insect and other vermin bites and the drinking of cold coffee and the ever present telling of lies. Great fun for all! (thanks to WD5CTQ) qrz.com
field day Amateur Radio activity in June to practice emergency communications dslreports
Field day An annual event in which portable stations are deployed, contacts made and new or prospective operators encouraged to get on the air. ar-wiki
Field Strength Meter A devie used to measure the strength of an electromagnetic field. ar-wiki
field strength meter a test instrument used to show the presence and strength of RF energy dslreports
Filter A circuit designed to pass only the desired frequency(s). icom
filter A circuit or device that will allow certain frequencies to pass while rejecting others dslreports
filter A circuit or device that will allow certain frequencies to pass while rejecting others. eham.net
Filter A circuit that will allow some signals to pass through it but will greatly reduce the strength of others. hamuniverse
Filter An electric circuit (often called a network) that allows certain frequencies to pass but rejects (attenuates) other unwanted frequencies. ar-wiki
final The last transmission by a station during a contact. Also the last amplifying stage of a radio transmitter dslreports
Fist The sending style of a particular CW operator. In the old days, telegraphers knew each other by their "fists" (thanks to WD5CTQ). qrz.com
FM 1) Frequency Modulation - 2) FM broadcast icom
FM Frequency Modulation qrz.com
FM Frequency Modulation. frequency - the rate of oscillation (vibration). Audio and radio wave frequencies are measured in Hertz. (cycles per second). eham.net
FM (Frequency Modulated or Frequency Modulation) The frequency of the carrier signal is changed (modulated) in direct proportion to the instantaneous amplitude of an input signal, usually the voice of the operator. The resulting transmitted signal is of constant amplitude, with increasing amounts of power removed from the carrier and displaced to the sidebands as the modulating signal increases in amplitude. ar-wiki
FOC First Class CW Operators' Club; an exclusive CW club based out of the United Kingdom. qrz.com
Foldback A circuit to limit power output when the transmitter senses elevated SWR or temperatures. icom
fox hunt a contest to locate a hidden transmitter dslreports
Fox Hunt Also known as ARDF (Amateur Radio Direction Finding). A contest to locate a hidden transmitter. ar-wiki
Frequency The number of complete cycles of an alternating current that occur per second. hamuniverse
Frequency The number of complete waves that pass a reference point per second. Expressed in Hertz (Hz) ar-wiki
frequency the rate of oscillation - audio and radio wave frequencies are measured in Hertz dslreports
Frequency Discriminator A type of detector used in FM receivers. hamuniverse
Frequency Modulation (FM) The type of signals used to communicate by voice (phone) over most repeaters. FM is a method of combining and RF carrier with an information signal, such as voice. The voice information (or data) changes the RF carrier frequency in the modulation process. hamuniverse
FSK Frequency Shift Keying icom
FSK Frequency-shift keying dslreports
FSK FSK Acronym for Frequency Shift Keying. A method of frequency modulation in which the frequency varies. (See AFSK, PSK). eham.net
FSK - Frequency Shift Keying A digital mode in which the signal is broken into "chunks". Each chunk is then shifted in frequency slightly above or below the central carrier. Effectively, frequency modulation used to carry a digital signal. ar-wiki
FSTV Fast Scan TV - Graphics (and audio) communication using TV broadcast signals, requires a wide bandwidth. icom
full duplex a communications mode in which a radios can transmit and receive at the same time by using two different frequencies dslreports
Full duplex An operation mode, which transmits and receives on different frequencies at the same time, as a telephone communication. icom
full-break in (QSK) allows a station to break into the communication without waiting for the transmitting station to finish dslreports
Fuse A device that self destructs when too much current passes through it - used for circuit protection. ar-wiki
Fuse An intentional weak link to guard against overload. icom
G-TOR (Golay - TOR) A digital FSK mode that offers faster transfer rate than PACTOR. Rarely used by ham radio operators. ar-wiki
GaAs FET Sensitive transistor, found in VHF/UHF receiver amplifiers, with a low noise floor. icom
Gain As it applies to antennas, see Antenna Gain qrz.com
Gain How much more effective an antenna is as a radiator than a half wave dipole (dBd) or a theoretical point source (dBi). A more directional antenna is considered to have higher gain. ar-wiki
gain, antenna increase in effective power radiated or receiveed by an antenna in a certain desired direction dslreports
Gel cell A small sealed lead-acid rechargeable battery which uses a gel instead of a liquid electrolyte. Often used as backup power in applications such as alarm panel installations. ar-wiki
General coverage The ability of a receiver to tune outside the amateur radio bands, typically over an extended continuous frequency range, to receive signals from non-amateur services such as shortwave broadcast or marine weather. ar-wiki
GHz gigahertz - billion (1,000,000,000) hertz dslreports
GHz Gigahertz - one billion Hertz (1 000 000 000 Hz) ar-wiki
Giga The metric prefix for 10(9), or times 1,000,000,000. hamuniverse
Global Positioning Service (GPS) A system utilizing satellites to determine the location of a person or object using a receiver. hamuniverse
GMT Greenwich Mean Time - the time at Greenwich UK. Related to Zulu and UTC. ar-wiki
GOTA (1) Get On The Air - a station available for supervised public use at Field Day events, ar-wiki
GOTA (2) Guides On The Air - a programme sponsored by YL organisations to introduce Girl Guides to amateur radio (see also: Jamboree on the Air) ar-wiki
gray line a band around the Earth that separates daylight from darkness dslreports
green stamp U.S. dollar bill sent along with a QSL card dslreports
Green Stamp U.S. dollar bill sent along with a QSL card (instead of an IRC) to offset postage costs of a return card. qrz.com
Grey Line also Gray Line a band around the earth that separates night from day. ar-wiki
Groud wave propagation Propagation via radio waves that travel along the surface of the earth. ar-wiki
Ground A direct connection from electrical equipment to the Earth - often achieved by driving a conducting spike into the ground, and connecting equipment to it. ar-wiki
ground Common zero-voltage reference point dslreports
Ground (2) A common zero voltage reference point. ar-wiki
Ground Plane A type of Omni-directional antenna. icom
Ground Wave Electrical wave directly travelling from transmitter. icom
ground wave propagation radio waves that travel along the surface of the earth, even beyond the horizon. dslreports
Ground-plane Antenna a quarter wavelength vertical antenna with radials extending horizontally from its base. ar-wiki
ground-plane antenna a quarter-wavelength vertical antenna with several radials extending horizontally from the base dslreports
Ground-Wave Propagation The manner in which radio waves travel along the Earth?s surface. hamuniverse
Grounding Electrical connection to the earth. icom
HAAT Height Above Average Terrain. ar-wiki
half duplex mode in which a radio transmits and receives on two different frequencies but performs only one of these operations at any given time dslreports
Half Duplex The ability for a transceiver to transmit and receive on two different frequencies, but ony one of these at any given time. ar-wiki
Half wave dipole An antenna that is half a wavelength total, fed at the centre. ar-wiki
half-wave dipole basic wavelength antenna consisting of a length of wire or tubing, open and fed at the center dslreports
Ham A licensed radio operator who enjoys the hobby and service of radio communications. icom
ham an amateur radio operator. eham.net
hamfest An event at which hams can buy sell and swap equipment. Often held in conjuction with lectures and demonstrations of equipment. ar-wiki
hamfest event at which hams meet to buy, sell, and swap equipment dslreports
hamfest ham festival, a social and commercial event at which hams meet to buy, sell, and swap equipment. eham.net
hand-held portable transceiver small enough to be carried easily dslreports
Harmonic 1. Children. 2. Secondary RF emission that is a multiple of the fundamental emission. qrz.com
Harmonic A signal from an oscillator or transmitter that occurs on whole-number multiples (2x, 3x, 4x, etc) of the desired operating frequency. Example: The second harmonic of 7.00mhz would be 14.00mhz. The third harmonic would be 21.00mhz hamuniverse
Harmonic An integer multiple of a frequency ar-wiki
Harmonic Integer multiples of the fundamental frequency being generated, harmonics are present if a signal is not perfectly sinusoidal or is undergoing intermodulation distortion. Harmonics located outside the desired band for transmission are normally removed with low-pass filters to avoid interference to other radio services. ar-wiki
Harmonic Multiple of a fundamental frequency. icom
Harmonic (of a ham) Slang term for the child of a ham. ar-wiki
HASL Height Above Sea Level. Often used for mountaintop stations such as repeaters and portable operations to describe their elevation. Measured in either feet or metres depending on the country. ar-wiki
Health and Welfare Traffic Messages about the well being of individuals in a disaster area. hamuniverse
Heat sink The heavy fins on the back of a transmitter to dissipate heat buildup. icom
Hellschreiber (Hell) A digital mode for sending and receiving text using facsimile (fax) technology. ar-wiki
Henry (H) The unit for inductance ar-wiki
Hertz Hz - The unit of measure for frequency. Named after Heinrich Hertz ar-wiki
Hertz the standard unit used to measure frequency (one Hertz equals one complete cycle per second) dslreports
Hertz the standard unit used to measure frequency (one Hertz equals one complete cycle per second). eham.net
Hertz (Hz) An alternating-current frequency of one cycle per second. The basic unit of frequency. hamuniverse
HF High Frequency - 3 MHz to 30 MHz dslreports
HF High Frequency - 3 MHz to 30 MHz. eham.net
HF High Frequency - 3-30 MHz range signals. Normally, 1.9 MHz band also included. icom
HF High Frequency; generally regarded as the band of frequencies between 1.8 MHz and 30 MHz qrz.com
HF High Frequency. Frequencies in the range 3MHz to 30MHz, also known as shortwave. ar-wiki
hi hi ha ha (laughter) the Morse equivalent of a laugh dslreports
hi hi The morse equivalent of laughter. ar-wiki
High Frequency (HF) Radio frequencies from 1800 kHz up to 30 MHz hamuniverse
High Pass Filter A filter designed to pass high frequency signals. ar-wiki
high-pass filter a filter designed to pass high frequency signals, while blocking lower frequency signals dslreports
high-pass filter a filter designed to pass high frequency signals, while blocking lower frequency signals. eham.net
High-Pass Filter A filter that allows signals above the cutoff frequency to pass through. It attenuates signals below the cutoff frequency. hamuniverse
Hiram Percy Maxim AKA "The Old Man" 1AW, ARRL founder. dslreports
Homebrew Home built equipment. ar-wiki
Homebrew Refers to equipment that is "home built"; something you built yourself. qrz.com
homebrew term for home-built, noncommercial radio equipment dslreports
Horizontal Polarization An antenna which projects a radio signal in which the electric field is parallel to the surface of the earth OR a radio signal of which the electric field is propagated parallel to the surface of the Earth. ar-wiki
horizontally polarized wave an electromagnetic wave with its electric lines of force parallel to the ground dslreports
HPF High Pass Filter icom
HSMM High Speed Multi Media. An ARRL working group and individual Amateur effort as well. Primary to High speed Voice, Video, and Data transmission on the Amateur allocations within the 2.4GHZ and 5.8GHz bands using commonly available WiFi equipment with High Gain Directional Antennas. Often referred to as the "hinternet" hinternet- Slang term often used in reference to HSMM. dslreports
HT Handheld Transceiver, also known as a Handy-Talkie or Walkie-Talkie. A radio small enough to be held in your hand. Typically used with radios that operate on the VHF ham bands or above. dslreports
HT Handi Talkie-- A portable handheld transceiver, battery operated, designed for one or more VHF/UHF ham bands. hamuniverse
HT (1) Handheld Transceiver or HandiTalkie. Usually refers to transceivers that operate in the 2m and 70cm amateur bands; these are self-contained hand-held radios which include an antenna and battery and transmit at low power. ar-wiki
HT (2) High Tension Voltage. Voltages over 500V ar-wiki
Hz Hertz icom
Hz Hertz; a unit used to measure frequency. Typically used with "Kilohertz" (KHz) to indicate 1,000 Hertz, or "Megahertz" (MHz) to indicate 1,000,000 Hertz. qrz.com
I/O Input/Output dslreports
Iambic A method of Morse Code keying. Holding both paddles at same time sends alternating dits and dahs (courtesy of VE3FFK). qrz.com
IARU International Amateur Radio Union. An international society that works for and with national organisations to promote the interests of hams. ar-wiki
IC Integrated Circuit, found in large scale chips within a radio. icom
IC Integrated Circuit. eham.net
ID Identification, as announcing station callsign at intervals. eham.net
IF Intermediate Frequency - Intermediate frequency, resultant frequency from heterodyning the carrier frequency with an oscillator, mixing incoming signals to an intermediate frequency enhances amplification, filtering and the processing signals dslreports
IF Intermediate Frequency - Internally converted frequency for amplification and other signal processing. icom
IF Intermediate Frequency, at which signals are amplified and processed internally within a receiver. ar-wiki
IF shift A function that electronically shifts the IF frequency from a center frequency to reduce interference. icom
IFK Incremental Frequency Keying a variant of MFSK ar-wiki
image A false signal produced in a superheterdyne receivers circuitry dslreports
Image frequency A frequency separated from that of the desired received signal by twice the receiver's intermediate frequency. ar-wiki
IMD Inter-Modulation Distortion - Distortion within RF circuits made with upper and lower adjacent channel signals. icom
impedance opposition to the flow of electric current and radio energy measured in ohms dslreports
Inductance A measure of how well a coil stores energy in the form of a magnetic field. ar-wiki
inductance a measure of the ability of a coil to store energy in a magnetic field dslreports
Inductance A measure of the ability of a coil to store energy in the magnetic field. hamuniverse
Inductor a coil of wire. Inductors are often used with capacitors in tuned circuits such as filters and oscillators. Some inductors are wound around a core of metallic material. This affects their inductance. ar-wiki
inductor a component composed of a coil of wire wound on a central core that stores energy in a magnetic field dslreports
Inductor An electrical component usually composed of a coil of wire wound on a central core. An inductor stores energy in a magnetic field. hamuniverse
Input Frequency A repeater?s receiving frequency. To use a repeater, transmit on the input frequency and receive on the output frequency. Also the frequency an electronic circuit is tuned to respond. hamuniverse
input frequency the frequency of the repeater's receiver (and your transceiver's transmitter) dslreports
Insulator A substance through which electricity does not pass easily - known as a dielectric in capacitors ar-wiki
Insulator A material that maintains a tight grip on its electrons, so that an electric current cannot pass through it (within voltage limits). Glass is an insulator. hamuniverse
Interface usually refers to a circuit used to connect the sound card of a computer to a transceiver to allow digital modes to be used. ar-wiki
Interference The interaction between a desired frequency and an undesired frequency. ar-wiki
Intermediate Frequency (IF) The output frequency of a mixing stage in a superheterodyne receiver. The subsequent stages in the receiver are tuned for maximum efficiency at the IF. hamuniverse
Intermod Derived from the expression "Intermodulation Distortion" (IMD). A problem caused in the receiver of a radio by a nearby transmitter's spurious signals which may fall on or very near to the receiver's receive frequency. In some cases, a perfectly clean transmitter (i.e., no spurious signals) can produce intermod if it overloads a receiver or if there is some other point for 3rd order intercept. Intermod which is close, but not necessarily right on, the receiver's frequency can cause the receiver to become less sensitive (also known as "desense"). qrz.com
intermod Short for "intermodulation." This generally means false or spurious signals produced by two or more signals mixing in a receiver or repeater station. eham.net
Intermodulation The undesired mixing of two or more frequencies, producing sometimes undesirable additional frequencies. ar-wiki
International Telecommunication Union (ITU) International radio organization responsible for distribution of radio frequencies. hamuniverse
Internet Remote Base Controlling an Amateur Radio station remotely through a computer. hamuniverse
Inverter a device that converts a DC source to and AC output. ar-wiki
Inverter An electrical device that converts direct current, DC, to alternating current, AC. Can be a source of noise on HF bands. icom
Ionizing Radiation Electromagnetic radiation that has sufficient energy to knock electrons free from their atoms, producing positive and negative ions. X-rays, gamma rays and ultraviolet radiation are examples of ionizing radiation. hamuniverse
Ionosphere a region in the atmosphere that contains ionised gasses that refract (bend) radio waves and direct them back to earth. ar-wiki
Ionosphere A region of electrically charged (ionized) gasses high in the atmosphere. The ionosphere bends radio waves as they travel through it, returning them to Earth. hamuniverse
ionosphere electrically charged region of the atmosphere 40 to 400 miles above the surface that refracts radio signals dslreports
ionosphere The electrically charged region of the Earth’s atmosphere located approximately 40 to 400 miles above the Earth’s surface that refracts radio signals. eham.net
IOTA Islands on the Air; for more information, please see http://www.islandchaser.com/. qrz.com
IOTA Islands On The Air. eham.net
IQ? Slang for "IQ of zero"; an idiot (courtesy of GI4FUE). qrz.com
IRC International Reply Coupon, used for pre-paid postage to foreign locations IRC dslreports
IRC International Reply Coupon. A system by which most country's postal systems provide a coupon which can be purchased, and then used by a sender in any other country to obtain return mail postage. This system allows you to provide return postage for those in another country, especially useful when you do not have access to that country's postage stamps or currency. IRC's are frequently used to assure return postage for a QSL card. For more information, please see QRZ's "QSL Corner" at http://www.qrz.com/qsl.html. qrz.com
IRC International Reply Coupon. A coupon that can be purchased at post offices which can be exchanged in foreign countries for return postage for a surface mail letter to the country that issued the coupon. eham.net
IRLP Internet Radio Linking Project developed by David Cameron, VE7LTD. Uses a network protocol called VoIP (Voice over IP) audio streaming. There are now over 1000 repeaters around the world connected by the internet through the Amateur radio internet radio linking project, 24 hours per day, 7 days a week. eham.net
IRLP Internet Radio Linking Project, allowing ham operators to join in on a party line, with the internet connecting repeaters together. icom
IRLP Internet Radio Linking Project. A method of cross-world linking of repeaters so that very basic equipment can be used to communicate with hams in other countries. ar-wiki
IRLP Radio Linking Project using VoIP dslreports
isotropic theoretical "Single Point" antenna used calculate gain dslreports
ISS International Space Station. hamuniverse
ITU International telecommunication Union. The international organisation set up to standardise and regulate radio communications. ar-wiki
ITU International Telecommunications Union, the body which specifies worldwide guidelines for use of electromagnetic spectrum for communications purposes dslreports
J antenna (J pole) a mechanically modified version of the zepp (zeppelin) antenna dslreports
J-Pole An antenna design that is relatively easy to assemble yourself. For more information, see http://www2.arrl.org/tis/info/JPole-V.html (Courtesy of ARRL). Note: The basic J-pole design can be applied to any frequency, as long as measurements are proper for that frequency. Furthermore, a 2-meter J-pole will also resonate on the 440 MHz (70 cm) ham band, making for a reasonable dual-band antenna. qrz.com
J-pole antenna Vertical antenna composed of two parallel elements of differing widths. The longer element is connected to signal and the shorter to ground at an intermediate point; the elements are connected to each other at the base.[1] ar-wiki
JOTA Jamboree On The Air - an annual event in which scouts worldwide can communicate with each other and radio amateurs using ham radio equipment. ar-wiki
JT65 A weak signal digital mode developed for use in the VHF and UHF bands for EME and other "reflected path" modes. The software for this mode, WSJT was written by Joe Taylor K1JT. ar-wiki
JT65 A weak signal digital mode, primarily used on HF and 6 m, for weak signal and EME type contacts (moon bounce, meteor scatter). icom
JT65-HF An adaptation of JT65, for use on the HF bands. ar-wiki
K The symbol used in CW ( Morse) and digital modes for "please respond" or "any station respond". The KN prosign is used to invite a specific station only to respond. ar-wiki
K- index A measure of the Earths magnetic field as measured at Boulder, Colorado dslreports
K-Index A three hourly index of geomagnetic activity relative to an assumed quiet day curve for the recording site. K index values range from 0 -very quiet- up to 9 -extremely disturbed- (Courtesy of IPS Radio and Space Services, Sydney, Australia). qrz.com
Kc Kilocycle; equivalent to KHz; regarded as an "old fashioned" way of describing frequency. qrz.com
Key A simple mechanical device used to send morse code ar-wiki
Key Device used by hand to produce Morse Code; can contain either a single, vertically travelling arm (see "Straight Key") or horizontally travelling paddles (see "Paddles") that are used to make ground connection and produce the Morse Code. qrz.com
key to press a key or button physically or electronically by computer. eham.net
Keyer An electronic circuit intended to interface an amateur CW transmitter to a paddle switch. While multiple variants exist, typically the keyer will send dit's when the paddle is held in one position and dah's in the opposite position. As the timing of the Morse dots and dashes is automatically controlled, code speed is more consistent than that sent manually using a straight key. ar-wiki
keyer device for sending Morse Code semi-automatically dslreports
Keyer Electronic device for sending Morse Code semi-automatically; connects to a key (see above). Dits are sent by pressing one paddle [of the key], dahs sent by pressing the other one (courtesy of VE3FFK). qrz.com
keyer Electronic device for sending Morse Code semi-automatically. Dits are sent by pressing one paddle of the key, dahs sent by pressing the other one paddle. eham.net
KHz See Hz qrz.com
Kilo Metric system multiplier x1000. Also Phonetic alphabet letter K ar-wiki
Kilo The metric prefix of 10(3), or times 1000. hamuniverse
kilocycles thousand cycles per second, replaced by kiloHertz (kHz) dslreports
kilocycles thousand cycles per second. Replaced by kiloHertz (kHz). eham.net
kilohertz one thousand hertz (see "hertz") dslreports
kiloHertz one thousand Hertz (see "Hertz"). eham.net
Kilohertz (KHz) one thousand Hertz (Hz) or one thousand cycles per second. ar-wiki
Knife edge The refraction of a signal over tall buildings and mountains. icom
ladder line open wire transmission (antenna) line dslreports
landline ham slang for telephone lines dslreports
LCD Liquid Crystal Display dslreports
LCD Liquid Crystal Display, primarily used for displaying frequency and radios operations. icom
LCD Liquid Crystal Display. A display device commonly used in portable computers. Contains a crystalline liquid whose optical properties change in the presence of an electric field to appear either light or dark. Must have an external light source to be visible. eham.net
Lead acid A rechargeable battery type most commonly used in automobiles and marine applications. As some batteries can deliver large amounts of current instantaneously and contain sulphuric acid, these must be handled with caution. ar-wiki
LED Light Emitting Diode, a low current low voltage component to illuminate a radio dial. icom
LED Light-emitting diode dslreports
LF Low Frequency - 30 kHz to 300 kHz dslreports
LF Low Frequency - 30-300 kHz range signals. icom
Li-Ion Lithium Ion - Rechargeable battery which has better capacity than Ni-Cd, Ni-MH, etc., no memory effect after repeated non-full charge/discharge cycles. icom
lid a poor operator, one who does not follow proper procedures or sends sloppy morse code dslreports
Lid In amateur radio, used to denote a poor or inept operator: a term originally from landline telegraphy.[1] [2] ar-wiki
LID Slang term, often referring to a CW operator with very poor practices and manners. qrz.com
Limiter A stage of an FM receiver that makes the receiver less sensitive to amplitude variations and pulse noise. hamuniverse
line-of-sight propagation term used to describe straight line propagation dslreports
Line-of-Sight Propagation The term used to describe VHF and UHF propagation in a straight line directly from one station to another. hamuniverse
linear an amplifier used after the transceiver output named for its purity of amplification dslreports
LIon Lithium-Ion. A type of rechargable battery commonly used with radio equipment. qrz.com
LIon, Li-Ion Lithium-Ion, a small but powerful rechargeable battery often factory-installed in laptop computers and handheld devices. As these cells are highly flammable if overheated, they are normally distributed only as part of pre-fabricated battery packs which internally include the requisite temperature sensors and charging circuits. ar-wiki
Loading coil An inductor placed in series with an antenna element in order to lower the antenna's resonant frequency. May be used singly or in conjunction with a capacity hat. ar-wiki
Lobe a an area in the radiation pattern of an antenna where the radiation is a maximum ar-wiki
Logging software A computer log of contacts, used for QSL card confirmations on contacts. icom
LOS Loss of Signal from a satellite; occurs when the satellite becomes "invisible" to the antenna as it goes below the horizon. qrz.com
Low-Pass Filter A filter that allows signals below the cutoff frequency to pass through and attenuates signals above the cutoff frequency. hamuniverse
low-pass filter a filter that allows signals below the cutoff frequency to pass through and attenuates signals above the cutoff frequency. eham.net
Lowfer One who experiments with radio communications at unusually low frequencies (typically 1750 Meters, which is 160-190 kHz and can be used under FCC Part 15). For more information, take a look at http://www.altair.org/lowfer.htm (courtesy of N4YWK). qrz.com
LPDA Log Periodic Dipole Array. A multiband Antenna ar-wiki
LPF Low Pass Filter icom
LSB (1) Lower Sideband, used primarily in single sideband operation below 10 MHz ar-wiki
LSB (2) Least Significant Bit, in transmitted digital data ar-wiki
LSB Lower Side Band icom
LSB Lower Side Band, the common single-sideband operating mode on the 40, 80, and 160 meter amateur bands. eham.net
LSB Lower Sideband qrz.com
LW Long Wave 150 - 300 KHz dslreports
mA/h milliampere per hour dslreports
Machine Slang for "repeater", and sometimes for rig. qrz.com
magnetic mount or mag-mount antenna with a magnetic base dslreports
Maritime mobile Amateur radio operation from aboard a marine vessel. icom
MARS Military Affiliate Radio Service icom
MARS Military Affiliate Radio System dslreports
Matchbox A device placed between a transmitter and an antenna to tune the circuit to resonance. Normally called an Antenna Tuner (thanks to WD5CTQ). qrz.com
Maximum Usable Frequency (MUF) The highest-frequency radio signal that will reach a particular destination using sky-wave propagation, or skip. The MUF may vary for radio signals sent to different destination. hamuniverse
Mayday A most urgent distress call (français «m'aidez» - help me) solely for use in life-threatening emergencies. The CW equivalent is SOS. Lesser incidents are signalled using "pan-pan" (français
«panne» - mechanical breakdown, typically a ship drifting helplessly or an aircraft's emergency landing) or "security" (français
«sécurité» - safety, for warnings such as reports of icebergs in shipping lanes).
ar-wiki
MAYDAY International distress call for voice communications. The word MAYDAY is NEVER used unless of dire emergency. It can be used in a normal sentence that does not mean or intend or can be mistaken for an emergency situation. hamuniverse
Mc Megacycle; equivalent to MHz; regarded as an "old fashioned" way of describing frequency. qrz.com
MCW Modulated Continuous Wave, a fixed audio tone modulates a carrier dslreports
Medfer One who experiments with radio communications at low frequencies such as those on the edges of the AM broadcast band (under FCC Part 15). qrz.com
Mega The metric prefix for 10(6), or times 1,000,000. hamuniverse
megacycles million cycles per second dslreports
megacycles million cycles per second. This terminology has been replaced by MegaHertz (MHz) eham.net
MegaHertz million hertz (see Hertz) eham.net
Megahertz One million Hertz (HZ) - same as one million cycles per second. ar-wiki
Memory bank A set of memory channels organized into a group. icom
Memory effect Rechargeable batteries such as Ni-Cd and Ni-MH types may be temporality getting less capacity as a result of repeated non-full charge/discharge cycles. It is called so since rechargeable batteries lose capacity as if "memorize" wrong full capacity level at less than full charge. Li-Ion batteries are free from this effect. icom
meteor scatter ionized trails of meteors used as a reflecting media dslreports
Metric Prefixes A series of terms used in the metric system of measurement. We use metric prefixes to indicate multiples of 10. hamuniverse
Metric System A system of measurement developed by scientists and used in most countries of the world. This system uses a set of prefixes that are multiples of 10 to indicate quantities larger or smaller than the basic unit. hamuniverse
MF Medium Frequency - (300-3,000 kHz) dslreports
MF Medium Frequency - 300 kHz-3 MHz range signals. icom
MHz See Hz qrz.com
MIC MICrophone icom
mic (mike) microphone dslreports
Micro The metric prefix for 10(-6), or divided by 1,000,000. hamuniverse
Microphone A device that converts sound waves into electrical energy. hamuniverse
Microphone A device that converts voice into electrical signals. ar-wiki
Microwave signals above 1GHZ in frquency. ar-wiki
microwave the region of the radio spectrum above 1 gigahertz (GHz) dslreports
Microwave Bands Division of the range of frequencies above 1GHz into a series of bands. ar-wiki
Milli The metric prefix for 10(-3), or divided by 1000. hamuniverse
Mobile A mode of operation in which a station may operate from a moving vehicle (mobile) or a ship at sea (maritime mobile). In CW, mobile and maritime mobile operators may identify using /M and /MM respectively. As a class of transceiver, mobile units fall between hand-held (5W or less) and base stations in both physical size and transmitted power. These units typically operate from the vehicle's battery and often transmit 50 watts or more using a vertical antenna mounted to use the metal vehicle body as a ground plane. ar-wiki
mobile an amateur radio station installed in a vehicle dslreports
mobile an amateur radio station installed in a vehicle - a mobile station can be used while in motion. (see also, portable). eham.net
Mobile In a vehicle, or other type station no fixed at a specific location. icom
Mobile Device A radio transmitting device designed to be mounted in a vehicle. hamuniverse
mode (see emission mode) dslreports
Mode The way electromagnetic waves are changed so that transmission of information is possible. ar-wiki
Modem Short for modulator/demodulator. A modem modulates a radio signal to transmit data and demodulates a received signal to recover transmitted data. hamuniverse
modulate create a radio emission so that it contains information (voice, Morse code, music, binary) dslreports
Modulate To vary the amplitude, frequency or phase of a radio-frequency signal. hamuniverse
Modulation Method of adding information to a radio frequency carrier. icom
Modulation The process of adding information to a carrier signal. ar-wiki
modulation The process of adding a signal to a carrier to transmit information. Can be used in reference to voice communications, but refers to digital data in the context of packet radio. (See demodulation, modem.) eham.net
Modulation The process of varying a radio wave in some way to send information. hamuniverse
Modulator A device that adds information to a carrier signal. ar-wiki
Morse Code The code used by CW operators instead of voice communications ar-wiki
MP73N A narrow band SSTV Mode ar-wiki
MPR Mass Produced Rig; a radio which is produced in large quantities; often used to describe radios that are NOT originally purchased in "kit" form. qrz.com
MSK Minimum Shift Keying. A modulation method similar to FSK in which the shift in Hertz is equal to half the signaling rate in BPS. (see AFSK, FSK, PSK). eham.net
MT63 A weak signal, digital communications mode, being used in MARS net traffic. icom
MUF Maximum Usable Frequency, the highest frequency that may return a skywave back to earth. icom
MUF Maximum Usable Frequency, the highest frequency that will support transmissions off of the ionosphere dslreports
MUF Maximum usable frequency. The highest frequency at which a skywave is reflected back to Earth at the ionosphere under current propagation conditions. Can vary rapidly depending on time of day and sunspot activity. ar-wiki
MUF Maximum Useable Frequency; that frequency above which expected propagation no longer exists. qrz.com
mV millivolt (1/1,000 volt) dslreports
MW Medium Wave - 300 - 3000 kHz dslreports
MW Medium Wave, 300-3000 kHz. This range includes the 160 metres amateur band, the AM broadcast band and the 2182 kHz marine radiotelephone band. ar-wiki
mW milliwatt (1/1,000 watt) dslreports
N-P Junction See "P-N Junction". qrz.com
NB Narrow band. Also noise blanker. ar-wiki
NB Noise Blanker qrz.com
NB Noise Blanker - A function reducing pulse-type noises. icom
NBFM Narrow band FM ar-wiki
NBFM Narrow Band FM icom
NCS Net Control Station qrz.com
NCS Net Control Station dslreports
Negative no, incorrect ar-wiki
Negative copy unsuccessful transmission ar-wiki
Negative Feedback A process in which a portion of the amplifier output is returned to the input, 180 degrees out of phase with the input signal. ar-wiki
Negative Offset Used in repeater systems where the repeater input frequency is lower than the output frequency. ar-wiki
net A group of stations that meet on a specified frequency at a certain time dslreports
Net a scheduled and structured on-air meeting of amateurs - often run and controlled by clubs. A directed net designates one station to act as net controller; that station is responsible for inviting other stations to check in (by sending their call signs) and then sequentially assigns each station a window of time in which to send traffic to other stations on the net. Intent is to avoid message collisions which otherwise may be caused by multiple stations attempting to send simultaneously. ar-wiki
Ni-Cd Nickel-Cadmium icom
Ni-MH Nickel-Metal Hydride icom
NiCad Nickel Cadmium, generally refers to a type of rechargeable battery dslreports
NiCad Nickel Cadmium, generally refers to a type of rechargeable battery with 1.2 volts per cell. ar-wiki
NiCd Or "Ni-Cad"; "Nickel Cadmium". A type of rechargable battery commonly used with radio equipment. qrz.com
NiMH Nickel Metal Hydride, generally refers to a newer type of rechargeable battery dslreports
NiMH Nickel Metal Hydride, generally refers to a newer type of rechargeable battery with the same voltage as NiCad cells but increased capacity. NiMH cells do not exhibit the memory effects associated with partial discharge of NiCads, but do still need to be recharged before use if they have been stored for a month or more. ar-wiki
NiMH Nickel Metal Hydride. A type of rechargable battery commonly used with radio equipment. qrz.com
NIST National Institute of Standards and Technology. US Government Standards Body for Time, Frequency, Measures, Weights. Formerly known as The National Bureau of Standards(NBS). dslreports
NODE A remotely controlled TNC/digipeater - used as a connect point in packet radio dslreports
node A general term used to indicate the different stations in a packet network. Nodes may be terminal nodes, network nodes, station nodes, and others. (see TNC, digipeater). eham.net
Noise Unwanted elecromagnetic energy that can interfere with signal transmission or reception. ar-wiki
Nonionizing Radiation Electromagnetic radiation that does not have sufficient energy to knock electrons free from their atoms. Radio frequency (RF) radiation is nonionizing. hamuniverse
Notch filter Sharp and narrow rejection filter for elimination of interfering signals icom
NPN A type of bipolar transistor that has a layer of P-type semiconductor material sandwiched between layers of N-type semiconductor material. ar-wiki
NPN A type of transistor that has a layer of P-type semiconductor material sandwiched between layers of N-type semiconductor material dslreports
NPN See "P-N Junction". qrz.com
NR Noise Reduction icom
NTS National Traffic System. Please see http://www.weca.org/nts.html for more information. qrz.com
Null A position in the radiation pattern of an Antenna where the radiation is zero or approaches zero ar-wiki
NVIS Near Vertical Incidence Skywave, a method of lowering a dipole, or an angled vertical, to enhance a high elevation of signal radiation and reception. icom
NVIS near-vertical-incidence-skywave, a propagation mode where signals are reflected back down from directly overhead. Useful for relatively short-distances, overcoming the limitations of the usual "skip-zone" distance" ar-wiki
Ø Slashed Zero - distinguishes a ZERO from the letter "O". Intended to resolve ambiguity in callsigns like ""W?OF". Not needed for callsigns like "W0RK". Can be produced by pressing Alt-216 on your PC keyboard (Note: you must use the numeric keypad, not the numbers across the top row of the keyboard. This method should work in most PC-based editors such as e-mail clients, word processors, etc.) qrz.com
OCF Off Centre Fed Dipole. A dipole that has sides of unequal length. These are multiband wire antennas ar-wiki
OFDM- Orthogonal Frequency Division Multiplexing. Common modulation type used in HSMM work. dslreports
offset (a repeater term) In order to listen and transmit at the same time, repeaters use two different frequencies. On the 2 metre ham band these frequencies are 600 kilocycles/second (or 600 kHz) apart. As a general rule, if the output frequency (transmit) of the repeater is below 147 MHz then the input frequency (listening) is 600 kHz lower. This is referred to as a negative offset. If the output is above 147 MHz then the input is 600 kilohertz above. This is referred to as a positive offset. eham.net
Offset Usually refers to the difference between a repeaters input frequency and output frequency. hamuniverse
Offset frequency Frequency difference between transmits and receives. icom
Ohm (<math> \Omega</math>) The unit for resistance ar-wiki
Ohm The basic unit of electrical resistance, used to describe the amount of opposition to current. hamuniverse
Ohm The fundamental unit of resistance offered when a potential of one Volt results in a current of one Ampere dslreports
Ohm Unit of resistance. icom
Ohm?s Law A basic law of electronics. Ohm?s Law gives a relationship between voltage (E), current (I), and resistance R. The voltage applied to a circuit is equal to the current through the circuit multiplied by the resistance of the circuit (E=IR). hamuniverse
Ohm's Law Named after George Ohm; V = IR. V = voltage, I = current, R = resistance ar-wiki
OLIVIA A digital mode using multiple FSK carriers: intended for operation under QRP or weak-signal conditions.[1] ar-wiki
OM Abbreviation meaning Old Man - any male operator, regardless of age or marital status. ar-wiki
OM friendship term, friend, pal or buddy dslreports
OM Old Man; affectionate way to address a fellow ham operator, like saying "Old Buddy!" qrz.com
OO Official Observer; a volunteer of the ARRL's Official Observer program who monitors the airwaves for FCC rules violations. For more information, please see http://www.arrl.org. qrz.com
Open Circuit An electrical circuit that does not have a complete path, so current can?t flow through the circuit. hamuniverse
open repeater (Repeater Term) a repeater whose access is not limited dslreports
Open Repeater A repeater that can be used by all hams who have a license that authorizes operation on the repeater frequencies. hamuniverse
Optoisolator Found in tuning knob circuits, where an LED shines through an interrupter to signal a data pulse. icom
OSC OSCillator icom
OSCAR Orbiting Satellite Carrying Amateur Radio ar-wiki
oscillate vibrate, generate an AC or other periodic signal dslreports
Oscillator Also known as a frequency synthesiser - A device that produces a signal at a particular frequency. ar-wiki
Oscillator The heart of all radios, needing a small amount of feedback to keep it oscillating. icom
oscilloscope an electronic test instrument used to observe wave forms and voltages on a cathode-ray tube. Displays time on the X-axis and amplitude on the Y-axis, Z-axis is intensity of the CRT spot dslreports
Output Frequency A repeater?s transmitting frequency. Can also be used when refering to a transmitter's fundamental transmitted frequency. hamuniverse
P-N Junction A P-N junction (or N-P junction) is formed by creating two substrate materials of P type and N type on a semiconductor. P type means it is doped with "free holes" (electron depletion) and the N type is doped with electrons. Of course by physics, the free holes and free electrons would like to neutralize each other.

A diode is formed with a P-N junction.

Basically, when you have a NPN transistor, you have two junctions ... an NP junction between the collector and base, and a PN junction between the base and emitter. Vice-versa with a PNP transistor. How you bias those junctions controls how the transistor works.
qrz.com
P5 North Korea. For DX'ers, the most unattainable contact or a non-existent station. The rarest callsign prefix as one of two countries worldwide (the other is 7O Yemen) to have had no licensed radio amateur service at all since 2002. ar-wiki
PA Power Amplifier icom
packet A group of bits including data and control elements which is transmitted as a whole. eham.net
packet controller Term used for a hardware TNC with an on-board modem. eham.net
Packet Radio A communications system in which information is broken into short bursts. The bursts (packets) also contain addressing and error-detection information. hamuniverse
packet radio a system of digital communication whereby information is transmitted in short bursts dslreports
packet radio a system of digital communication whereby information is transmitted in short bursts. The bursts ("packets") also contain callsign, addressing and error detection information. eham.net
Packet radio An early digital radio mode developed in Canada in 1978. ar-wiki
PACTOR An FSK mode that combines packet and AMTOR technologies. ar-wiki
PACTOR Digital radio modulation used mostly on the HF bands for digital messaging. icom
paddle Morse code key dslreports
Paddles Short for "Morse Code Key", one that contains small paddles that are tapped in order to produce semi-automatic Morse Code (when connected to a "keyer"). qrz.com
Parabolic Antenna An antenna in the shape of a dish with a parabolic cross section. ar-wiki
Parallel Circuit An electrical circuit in which the electrons follow more than one path in going from the negative supply terminal to the positive terminal. hamuniverse
Parallel circuit usually used to describe a tuned circuit in which the capacitive and inductive elements are parallel to each other. ar-wiki
Parawatch [Dualwatch] icom
Patch Short for "Phone Patch". qrz.com
PBT PassBand Tuning - A function to reduce interference by electronically narrowing the IF bandwidth. icom
PC Printed Circuit dslreports
PCM pulse code modulation based on the Shannon's communication theory dslreports
peak-inverse-voltage (PIV) the maximum voltage a diode can withstand when it is reverse biased (not conducting) dslreports
PEP Peak Envelope Power - RF power at maximum amplitude. icom
PEP Peak envelope power - the average power of a signal at its largest amplitude peak dslreports
PEP Peak Envelope Power; used to measure power output of an single sideband signal. qrz.com
PEP Peak envelope Power. The average power sent to the transmission line by the transmitter. Can be calculated by multiplying Peak Envelope Voltage (PEV) by 0.707 ar-wiki
Period The time in seconds taken for a complete wave to pass a reference point, period is the reciprocal of frequency. ar-wiki
PEV Peak Envelope Voltage. The maximum voltage on a transmission line during transmission. ar-wiki
phase the time interval between one event and another in a regularly recurring cycle dslreports
phase modulation varying the phase of an RF carrier in response to the instantaneous changes in an audio signal dslreports
Phone Another name for voice communications. hamuniverse
phone voice modulation dslreports
phone patch A connection between a two-way radio unit and the public telephone system dslreports
Phone Patch Device allowing audio from a telephone line to be placed in the audio circuits of a transmitter/receiver (thanks to WD5CTQ). qrz.com
Phonetic Alphabet Specific, easily identifiable, non-confusable words are used instead of the letters of the alphabet. ar-wiki
Phonetic Alphabet Standard words used on voice modes to make it easier to understand letters of the alphabet, such as those in call signs. hamuniverse
Photovoltaic Solar cell, converting photons to electricity. icom
Pi pad one of the possible configurations used in Attenuators ar-wiki
picket fencing condition experienced on VHF and above where a signal rapidly fluctuates in amplitude causing a sound akin to rubbing a stick on a picket fence dslreports
Pico The metric prefix for 10(-12), or divide by 1,000,000,000,000. hamuniverse
pico the metric prefix for 10^-12, or divide by 1,000,000,000,000 dslreports
Piezoelectric Effect the ability of a substance to produce an electric charge when it is deformed physically. ar-wiki
pileup multiple stations calling a DX or contest station dslreports
Pink Ticket FCC Notice of Rule Violation qrz.com
pirate Station using an existing callsign and illegally operating on the air dslreports
PL Private Line with repeaters, same as CTCSS-- low frequency audio tones used to alert or control receiving stations dslreports
PL Private Line, Motorola's trademarked name for CTCSS. qrz.com
PL Private Line, used to block repeater interference. Referred to as PL tone. hamuniverse
PLL Phase Locked Loop - Circuit to synthesize the different frequencies a radio will operate on. icom
PLL Phase-lock loop dslreports
PM Phase Modulation or Pulse Modulation qrz.com
PM Phase Modulation, similar to Frequency Modulation dslreports
PNP A semiconductor device composed of an N layer sandwiched between two P layers. ar-wiki
PNP a type of transistor that has a layer of N-type semiconductor sandwiched between layers of P-type semiconductor material dslreports
PNP See "P-N Junction". qrz.com
Pocket beep Beeping function when specific signal is received. icom
Polarization Used to describe the orientation of the electric field produced by an antenna compared to the surface of the Earth. ar-wiki
Portable A mode of operation in which a station may be moved for rapid deployment from a temporary location, but is not able to operate while mobile. In CW, portable operators may identify using /P. Portable stations differ from mobile stations in that large antennas or other structures must be folded or stowed away in order to move the station to a new location. While well-suited to field day or emergency/disaster operations, portable stations normally do not have a mobile station's ability to continue transmission while in motion. ar-wiki
portable A portable station is one that is designed to be easily moved from place to place but can only be used while stopped. Portable operation is away from the home base station. (see also, mobile). eham.net
Portable Device A radio transmitting device designed to have a transmitting antenna that is generally within 20 centimeters of a human body. A transceiver that is handheld like "HT". hamuniverse
Power The rate of energy consumption. Calculated by multiplying voltage by current, P = VI ar-wiki
Power The rate of energy consumption. We calculate power in an electrical circuit by multiplying the voltage applied to the circuit times the current through the circuit (P=IE). hamuniverse
Power Supply A circuit that provides a direct-current (dc) output at some desired voltage from an ac input voltage. hamuniverse
Power supply Usually converts household (110/220/230/240) Volts AC to 12 Volts DC. Sometimes built in, sometimes external to the equipment. icom
Priority Traffic Emergency-related messages, but not as important as Emergency traffic. hamuniverse
Priority watch Reception mode, which by a selected frequency is always periodically, checked when VFO is set to different frequency icom
Product Detector A device that allows a receiver to process CW and SSB signals. hamuniverse
Propagation How well a signal is transferred from the sending station to the receiving station, as a function of the path type (ground wave, sky wave reflection or direct line-of-sight) and related atmospheric conditions. ar-wiki
propagation the means or path by which a radio signal travels from a transmitting station to a receiving station dslreports
Propagation The manner in which radio waves travel. hamuniverse
PSK Phase Shift Keying - a digital mode. ar-wiki
PSK Phase Shift Keying. A method of transmitting digital information in which the phase of the carrier is varied in accordance with the digital signal. eham.net
PSK31 A digital mode which is rapidly growing in popularity; utilizes phase shift keying (PSK) which is transmitted at 31 baud (speed). For more information, please see http://www.psk31.org. qrz.com
PSK31 A digital transmission mode - Phase Shift keying with 31.25 baud rate - See PSK31 dslreports
PSK31 A type of radio-teletype using Phase Shift Keying with a very narrow bandwidth as an efficient way of communicating. icom
PTT Push to talk ar-wiki
PTT Push To Talk icom
PTT Push To Talk, the switch in a transmitter circuit that activates the microphone and transmission circuitry. eham.net
PTT Push To Talk, the switch in a transmitter circuit that activates the microphone circuitry dslreports
PTT Push to Talk; a button on a microphone or on the side of a handheld radio which activates the transmitter. qrz.com
PWR PoWeR icom
Q figure of merit with regard to a tuned circuit (source: ARRL Handbook). With regard to an antenna circuit, the Q has an inversely proportionate relationship to useable bandwidth (with reasonable SWR). For example, an antenna with "high Q" will not provide a good SWR over a very wide range of frequencies. qrz.com
Q Response of a circuit over a specific bandwidth. Also, Ham Slang for a contact, or QSO. icom
Q Code Three letter codes used instead of sentences or phrases. ar-wiki
Q of a circuit The quality factor of a resonant circuit - the ratio of stored power to dissipated power in the Reactance and Resistance of the circuit. ar-wiki
Q signals Three-letter symbols beginning with Q. Used on CW to save time and to improve communication. hamuniverse
Q-signals a set of three-letter codes which are used by amateurs as abbreviations dslreports
Q-Signals Originally developed by CW (Morse Code) operators to make certain, frequently used phrases short and concise -- a sort of Morse Code "shorthand". Common signals include "QST" (announcement), "QSL" (confirmation), and "QTH" (location), and "QRZ" ("who is calling me?"). For more Q-signals, please see http://en.wikipedia.org/wiki/Q_code. qrz.com
QAM Quadrature Amplitude Modulation. A method that allows simultaneous frequency and amplitude modulation of a signal. ar-wiki
QCWA Quarter Century Wireless Association, a radioamateur club with local chapters in which membership is offered solely to operators who were first licensed twenty-five or more years ago. ar-wiki
QCWA Quarter Century Wireless Club, an organization for hams who have held a license for 25 or more years. For more information, see http://www.qcwa.org. qrz.com
QPSK Quadrature Phase Shift Keying. Also known as Quadraphase Phase Shift Keying. A method of modulating a carrier in digital transmissions by changing its phase four times, with each change being represented by two binary digits. ar-wiki
QRM Are you being interfered with? I am being interfered with. dslreports
QRM Man made noise. Can be used to indicate noise interfering with an amateur station or an amateur station interfering with other spectrum users. ar-wiki
QRN Are you troubled by static? I am being troubled by static. dslreports
QRN Electromagnetic noise from natural sources interfering with amateur transmissions. ar-wiki
QRO Should I increase power? Increase power dslreports
QRP Low power operation, usually 10 Watts or less. icom
QRP Low power operation, usually 5 watts output or 10 watts input power dslreports
QRP Low power operation, usually 5 watts output or 10 watts input power. eham.net
QRP Low power operations - usually understood to mean power at or below 5 watts. From QRP, a code requesting that a station reduce its transmitted power. ar-wiki
QRPp Very low power operation - at or below 1 Watt. ar-wiki
QRSS Very low speed operation - typically CW below one character per minute, intended for machine-assisted reception under extreme QRP or noisy/weak signal conditions. Bandwidth used is a small fraction of 1 Hz. From QRS, a code requesting "send more slowly". ar-wiki
QRT Shall I stop sending? Stop sending dslreports
QRZ Who is calling me? You are being called by --- dslreports
QSB Fading (of signals). Used in signal reports eg "your signal is experiencing rapid QSB tonight" ar-wiki
QSL Confirmation of receipt of transmission ar-wiki
QSL to acknowledge receipt; also commonly used to indicate "I understand", "I copied all OK" and term for sending cards by mail to confirm contact dslreports
QSL to acknowledge receipt. Commonly used to indicate "I understand", "I coped your transmission (or report) all OK". Also used as a term for sending cards by mail to confirm a two way contact with a station, such as QSL via the bureau. (see bureau or burro). eham.net
QSL Bureau Also known as the "buro"; an organization that provides a collecting and distributing point for QSL cards. In large scale situation, typically broken into an "incoming" and "outgoing" bureaus. A good example is the biggest QSL Bureau representing the U.S., the ARRL QSL Bureau. For more information, see ARRL's Incoming Bureau at http://www.arrl.org/qsl/qslin.html and their Outgoing Bureau at http://www.arrl.org/qsl/qslout.html. qrz.com
QSL Card A postcard that serves as a confirmation of communication between two hams. hamuniverse
QSL Card Often referred to as simply a "QSL"; similar in size to a postcard, it is used to "confirm" (or show proof of) having made contact with another station on the air; applies to both "two-way" and "one-way" (SWL) communications; the QSL card is filled out by the issuer/sender, and by convention it contains (1) the station contacted, (2) UTC date and time of contact, (3) frequency/band, (4) signal report (RST), and (5) callsign and address of issuer/sender. QSL cards are commonly used as proof of fulfilling various operating awards such as DXCC, WAS, etc. qrz.com
QSL Manager A person, commonly an Amateur Radio operator, who manages the receiving and sending of QSL cards for a particular Amateur Radio station (the "managed" station). Often, a QSL Manager performs this service because the managed station either has difficulty handling the volume of incoming QSL cards, or the station is geographically located such that it is difficult or impossible for that station to accept and/or send QSL cards. It is very common for "rare" DX stations and DXpeditions to have a QSL Manager. qrz.com
QSL Manager A person, usually an Amateur Radio operator, who manages the receiving and sending of QSL cards for a managed station) dslreports
QSL Manager A person, usually an Amateur Radio operator, who manages the receiving and sending of QSL cards for a managed station). A QSL Manager is needed because the managed station either has difficulty handling the volume of incoming QSL cards, or the station is geographically located such that it is difficult or impossible for that station to accept and/or send QSL cards. It is very common for "rare" DX stations and DXpeditions to have a QSL Manager. eham.net
QSO Can you communicate with ---? Also a common way to refer to a contact with another ham dslreports
QSO two way conversation dslreports
QSO two way conversation. eham.net
QST Another Q-signal. Refers to News Bulletin, also the monthly magazine published by the ARRL. dslreports
QSY Shall I change frequency? Change frequency to ---- dslreports
QTH Home, home location, station location ar-wiki
Quartz crystal a crystal of ?silicon dioxide cut to vibrate at a particular frequency when an electric current is applied to it. Used in high stability oscillators ar-wiki
RAC Radio Amateurs of Canada, a national amateur radio organization in Canada. eham.net
RAC Radio Amateurs of Canada, a national amateur radio organization in Canada. See leagues dslreports
RACES Radio Amateur Civil Emergency Service dslreports
Radio Amateur Civil Emergency Service (RACES) a part of the Amateur Service that provides radio communications for civil preparedness organizations during local, regional or national civil emergencies. hamuniverse
Radioteletype (RTTY) Radio signals sent from one teleprinter machine to another machine. Anything that one operator types on his teleprinter will be printed on the other machine. hamuniverse
ragchewing chatting informally via radio dslreports
RDF Radio Direction Finding dslreports
reactance opposition to current that a capacitor or inductor creates in an AC circuit dslreports
reading the mail to listen to a QSO without participating dslreports
Receiver A device that converts radio signals into audio signals or some other form of information. hamuniverse
Reflected power Non-radiated power dissipated as heat when the transmitter is mismatched to the antenna or load. icom
Reflection Signals that travel by line-of-sight propagation are bounced off of large objects like buildings, mountains, etc. hamuniverse
Refraction Radio waves are bent back to earth, via the ionosphere, by refraction. icom
Regulator A device - often built to employ a Zener Diode as reference - which maintains a constant output voltage over a range of load currents and input voltages. ar-wiki
Remote Base An HF amateur station setup to operate by remote control, usually by connecting to the Internet through a computer. hamuniverse
repeater a receiver/transmitter that listens for transmission and re-transmits them dslreports
Repeater A system consisting of at least one transmitter, one receiver, and a controller, which receives a signal on one frequency and retransmits it on another frequency. Repeaters are typically located in high locations so that they have greater coverage area. They greatly increase a user's communication range since they can retransmit his/her signal across all of its coverage area. Repeaters are most commonly used on the 2 meter and 70 centimeter bands. See also "Simplex Repeater". qrz.com
Repeater A transceiver - often comprised of separate transmitted and receiver linked by controlling hardware. A repeater picks up a radio signal and re-transmits it, allowing weak stations to be heard from further away than normally possible. ar-wiki
Repeater An amateur station that receives a signal and retransmits it for greater range. hamuniverse
Repeater Radio systems, which receive incoming signal and re-transmit it for extended communication area. Normally put on geographically high locations for VHF/UHF hand portables. icom
Repeater council A voluntary regional amateur organisation coordinating repeater frequency pair assignments to minimise interference. As no individual amateur group owns any given radio frequency, a council does not exercise legal authority to force individual repeater operators onto a specific frequency, height, location, power or directional pattern. Nonetheless, amateurs are obligated by national laws to avoid interference to other amateur stations and official regulatory agencies will resolve interference complaints between repeater operators by forcing uncoordinated repeaters to move off frequencies where their operation interferes with any coordinated repeater. ar-wiki
Resistance The ability to oppose or resist an electric current. hamuniverse
Resistance The measure of how much an object (a resistor) opposes the flow of electric current. ar-wiki
Resistivity The measure of how strongly a material (eg plastic) opposes the flow of electric current. ar-wiki
Resistor A device that opposes the flow of electric current. ar-wiki
Resistor Any material that opposes a current in an electrical circuit. An electronic component especially designed to oppose current. hamuniverse
resonance condition where Xc = XL, establishing a resonant circuit - used for selectivity (parallel circuit) or a maximum impedance circuit (series) dslreports
Rettysnitch See definition of Wouff-Hong dslreports
RF Radio Frequencies: Frequencies that can pass through space as electromagnetic radiation. ar-wiki
RF Radio Frequency icom
RF Radio Frequency, emissions in the radio portion of the electromagnetic spectrum dslreports
RF Radio Frequency, emissions in the radio portion of the electromagnetic spectrum. eham.net
RF Radio Frequency; typically used as slang for "Radio Frequency Energy". qrz.com
RF Burn A burn produced by coming in contact with exposed RF voltages. hamuniverse
RF Burn A painful sensation felt when coming into direct contact with RF energy; can be dangerous when experienced with high levels of RF power. qrz.com
RF Carrier The electromagnetic wave produced by a transmitter at a particular frequecy. hamuniverse
RF ground Connection of amateur equipment to earth ground to eliminate hazards from RF exposure and reduce RFI. icom
RF Radiation Waves of electric and magnetic energy. Such electromagnetic radiation with frequencies as low as 3 kHz and as high as 300 GHz are considered to be part of the RF region. hamuniverse
RF Safety Preventing injury or illness to humans from the effects of radio-frequency energy. hamuniverse
RFI Radio Frequency Interference dslreports
RFI Radio Frequency Interference (also BCI - broadcast interference, TVI - television interference). Normally resolved by installation of filters at the transmitter, the affected receiver(s) or both. ar-wiki
RFI Radio Frequency Interference. eham.net
rig a radio (transmitter, receiver, or transceiver) dslreports
Rig Radio qrz.com
Ripple The residual AC left over after rectification and filtering when an AC supply has been converted to DC' ar-wiki
RIT Receive Incremental Tuning, Receive Independant of Transmit. The ability to shift the receive frequency of a transceiver away from the transmit frequency by a small amount. ar-wiki
RIT Receive Incremental Tuning; a common feature on HF radios that allows the user to slightly change the receive frequency while leaving the transmit frequency the same. qrz.com
RIT Receiver Incremental Tuning - Fine-tuning receive frequency without changing displayed or memory frequency. icom
RIT Receiver incremental tuning. Also known as a Clarifier dslreports
RMS Root mean square dslreports
RMS Root Mean Square. Calculated by squaring each of the values on a signal, calculating the mean of the squares, and then taking the square root of the mean. approximately 0.707 of the peak value. ar-wiki
roger I understand - Received 100% In CW: "R" dslreports
ROS Digital An MFSK digital mode created in 2009. ar-wiki
rotator a device attached to an antenna mast which rotates it dslreports
rotor (see "rotator") dslreports
Rover A station that operates from several grid squares or counties during a contest dslreports
RSGB Radio Society of Great Britain - national amateur radio organisation of UK. ar-wiki
RSQ code Used to describe the readability, strength and quality of digital modes. ar-wiki
RST Readability, Signal, and Tone, a three-digit report indicating how well an operator's emissions are being received dslreports
RST Readability, Strength, Tone; a system by which a received signal quality is graded, and a signal report is given. "Readability" is judged on a scale from 1 to 5, and "Strength" and "Tone" are judged on a scale from 1 to 9. "Tone" does not apply to a "phone" (voice) signal. A very high quality CW signal is "599" (pronounced "five nine nine"), and such a phone signal is "59" (pronounced "five nine"). qrz.com
RST code Used to describe the readability, strength and tone of voice or CW transmissions. ar-wiki
RSV code used to describe the readability, stength and video quality of SSTV transmissions ar-wiki
RTTY Radio TeleTYpe icom
RTTY radio teletype - A form of digital communications dslreports
RTTY radio teletype - A form of digital communications. eham.net
RTTY Radio Teletype; popular digital mode on HF qrz.com
RTTY Radioteletype. ar-wiki
Rubber Duck Also known as "Rubber Duckie", a flexible antenna normally found on hand-held tranceivers. Inefficient, but useable, and they don't poke you in the ribs too badly either! (thanks to WD5CTQ). qrz.com
Rubber duck Nickname for the flexible rubber antennas supplied with many handheld transceivers. ar-wiki
RX Abbreviation for "receiver" or "receive". qrz.com
RX Abbreviation for receive or receiver ar-wiki
RX Receive icom
S meter A meter on a receiver that displays the relative strength of an incoming signal. ar-wiki
S-Meter Signal Strength Meter dslreports
S/N Signal to Noise ratio icom
S/N Signal-to-noise ratio dslreports
Safety RF exposure limits, set by ANSI (American National Standards Institute), to minimize over exposure to RF signals from a nearby antenna. icom
SAR Search And Rescue icom
SASE Self Addressed, Stamped Envelope; for more information, please see QRZ's "QSL Corner" at http://www.qrz.com/qsl.html. qrz.com
SASE Self-addressed, stamped envelope dslreports
SASE Self-addressed, stamped envelope. eham.net
Scan Continually sweeping frequencies looking for signals. icom
Scan Edge End and start frequencies for a scanning range. icom
Scratch Pad Memory Temporary frequency memories for quick access. icom
selectivity Ability of a receiver to reject signals adjacent to tuned signal dslreports
Semi Duplex An operation mode in which transmits and receives is accomplished on different frequencies alternatively. icom
Semiconductor an element that is normally an insulator but which can, under certain physical conditions, be made to conduct. ar-wiki
sensitivity A receivers ability to receive weak signals dslreports
Sensitivity Indicates how weak a signal the receiver can detect. icom
separation or split the difference (in kHz) between a repeater's transmitter and receiver frequencies dslreports
series circuit an electrical circuit in which all the electrons must flow through every part of the circuit dslreports
Series Circuit an electrical circuit in which all the electrons must flow through every part of the circuit. There is only one path for the electrons to follow. hamuniverse
Series circuit Usually used to describe tuned circuits in which the capacitive and inductive elements are in series with each other. ar-wiki
Set mode An operation mode used for radio. To set less frequently used control features. icom
SFI See "Solar Flux Index" qrz.com
shack Ham station operating area dslreports
SHF Super High Frequency 3 - 30 GHz dslreports
Short Circuit An electrical circuit in which the current does not take the desired path, but finds an unintended shortcut instead. Often the current goes directly from the negative power-supply terminal to the positive one, bypassing the rest of the circuit. Often called a "short". hamuniverse
short path in degrees - the direct great signal bearing path between two locations. Long path is the reciprocal bearing dslreports
signal a radio emission dslreports
Signal Report System (RST) A system of numbers used for signal reports: R is readability, S is strength and T is tone. hamuniverse
Signal to Noise Ratio S/N the ratio of signal power to noise power. The better the S/N ratio, the better the quality of the signal and the easier it is to decode. ar-wiki
silent key a deceased amateur operator dslreports
simplex a communications mode in which a radio transmits and receives on the same frequency dslreports
Simplex An operation mode where transmit and receive frequency is same. icom
Simplex Communicating directly from radio to radio (without the use of an intermediary repeater). This term is normally used in the context of environments that frequently use repeaters. qrz.com
Simplex Transmit and receive on the same frequency - most often used when communicating directly (not used when operating via voice repeaters). ar-wiki
Simplex Operation Receiving and transmitting on the same frequency. Both stations use the same frequency by taking turns. hamuniverse
Simplex Repeater A radio that has a digital audio store-and-forward relay system. Produces results similar to that of a conventional repeater. qrz.com
Sine Wave electricity building slowly to a peak voltage in one direction, then decreasing to zero and reversing to build to a peak in the opposite direction. hamuniverse
Single Sideband (SSB) Emission mode that describes the type of voice emission used on the ham bands. There is no carrier produced in a SSB transmission. Only the side band/s are transmitted. USB = upper side band...LSB = lower side band. Introduction to SSB here! hamuniverse
SITOR-A Simplex teleprinting over radio system, mode A dslreports
SITOR-B Simplex teleprinting over radio system, mode B (FEC mode) dslreports
SK Silent Key, a term used in memory of a deceased radio operator. The SK prosign in Morse code indicates the end of a message. ar-wiki
SK Silent Key, an amateur term for indicating that a ham has passed away. Also one of the prosigns - meaning "end of contact" dslreports
Skip Skip is a radio phenomenon in which signals are reflected or refracted by the atmosphere and return to earth in unexpected places, far away from the normal reception zones. In between transmitter and receiver there is a zone where no transmissions can be heard ar-wiki
Skip Distance The shortest distance, for a fixed frequency, between transmitter and receiver. ar-wiki
Skip Zone An area of poor radio communication, too distant for ground waves and too close for sky waves. Radio waves ‘skip or hop over it.’ hamuniverse
skip zone dead zone, too far for ground wave propagation and too near for sky wave propagation dslreports
Skip Zone The distance between the point of no reception and the closest point of reception. ar-wiki
sky wave propagation the transmitting of radio waves which reflect off of the ionosphere dslreports
Sky-Wave Propagation The method by which radio waves travel through the ionosphere and back to Earth. Sometimes called skip, sky-wave propagation has a far greater range than line-of sight and ground-wave propagation. hamuniverse
skyhook antenna dslreports
Skywarn Trained volunteer storm spotters for the National Weather Service. icom
Slug A short, cylindrical unit that is inserted into a Bird? Wattmeter (or similar) that allows the unit to read power (watts) for a particular frequency range. A slug always has a finite frequency range and a maximum power rating. By swapping out different slugs, the wattmeter can be used for many different frequencies and power ranges. qrz.com
SMA Sub-Miniature a connector - Type of antenna connector, used in VHF/UHF portable. icom
SNP, SNPF Shared non-protected pair, shared non-protected frequency. In repeater coordination, an input/output frequency pair on which no fixed/permanent repeater stations have been deployed. These frequencies remain available for temporary use only within a very limited coverage area by portable public service, emergency, search and rescue operations or short experiments. Individual temporary repeaters on these frequencies are not regionally-coordinated, so are not protected from mutual interference with other temporary repeaters on the same frequency.[1] ar-wiki
Solar Flux Index A measurement of radio emission from the sun. HF propagation conditions are considered good when this number is high and the A- and K-index numbers are low. qrz.com
SOS A Morse Code call for emergency assistance. Three short, three long and three short transmissions using CW. hamuniverse
SOTA Summits On The Air. An international event in which operators gain points from contacts to and from mountain summits over 500m. ar-wiki
SP SPeaker icom
Space Station An amateur station located more than 50 km above the Earth?s surface. hamuniverse
Special Event A radio operating event, usually on HF, in which a group or organization celebrates an event or holiday by making contacts and offering special QSL cards or certificates to confirm the contact. Ham Radio magazines, such as QST, usually publish a monthly list of Special Events. qrz.com
Specific Absorption Rate (SAR) A term that describes the rate at which RF energy is absorbed into the human body. Maximum permissible exposure (MPE) limits are based on whole-body SAR values. hamuniverse
speech processor A circuit that increases the average level of the modulating signal applied to a transmitter dslreports
splatter a type of interference to stations on nearby frequencies dslreports
Split An operating mode in which the transmit and receive frequency is different. icom
split DX stations often operate split - that is transmitting on one frequency and listening at a different frequency dslreports
Split operation Direct communications where transmit and receive are offset from each other in frequency - most often used by DXpedition stations which must accommodate large numbers of incoming calls. ar-wiki
Sporadic E-Skip Unexpected and unpredictable propagation using refraction in the E Layer. ar-wiki
SQL Squelch - A circuit that mutes the receiver when no signal is present, thereby eliminating band noise dslreports
SQL SQueLch - A function muting audio output for set conditions. icom
Squelch A user-adjustable electronic circuit in a receiver or transceiver which masks unwanted noise in the absence of a signal. ar-wiki
squelch tail (Repeater Term) A brief bit of noise heard between the end of a radio transmission and the reactivation of the receivers squelch circuit dslreports
SSB Single Side Band dslreports
SSB Single Side Band. eham.net
SSB Single Sideband qrz.com
SSB Single Sideband. A transmission mode used mainly in the HF bands. ar-wiki
SSTV Slow Scan Television dslreports
SSTV Slow Scan Television - still picture ham transmissions. ar-wiki
SSTV Slow Scan Television. eham.net
SSTV Slow Scan TV - Graphics communication using narrow bandwidth. icom
Standing Wave The vector sum of two waves - in ham radio, this most usually refers to the forward and reflected waves in a feedline ar-wiki
Straight Key A device for sending Morse Code, consisting of a single arm making contact with another point to complete a circuit and key a transmitter (thanks to WD5CTQ). qrz.com
straight key a non-electronic Morse code key with one paddle dslreports
Sunspot A region on the sun where an electromagnetic "storm" is happening. These have an effect on propagation ar-wiki
Sunspot Cycle A cycle of approximately 11 years in which the number of sunspots increases and decreases. The broader sunspot cycle is 22 years as the polarity of the sunspots reverses every 11 years. ar-wiki
Sunspot Cycle The number of sunspots increases and decreases in a predictable cycle that lasts about 11 years. hamuniverse
Sunspots Dark spots on the surface of the sun. When there are few sunspots, long-distance radio propagation is poor on the higher-frequency bands. When there are many sunspots, long-distance HF propagation improves. hamuniverse
superheterodyne a radio receiver scheme which beats or heterodynes a second radio frequency to the incoming radio signals. The combined frequencies form an intermediate (IF) third frequency dslreports
Susceptance the reciprocal of Reactance, measured in Siemens: symbol S ar-wiki
SW Short Wave dslreports
Switching Power Supply A power supply that uses switching transistors (on-off) to increase the efficiency of the power conversion, rather than the simple transformer/rectifier design of traditional power supplies. qrz.com
SWL Short Wave Listener icom
SWL Short Wave Listening dslreports
SWL Shortwave Listener; one who enjoys listening to shortwave transmissions, without intention of transmitting. qrz.com
SWL Shortwave listener. While SWL's do not operate licensed transmitting stations, some are using equipment capable of receiving both radioamateur and broadcast signals. For both, SWL's may submit reception reports in order to receive QSL cards. On VHF/UHF and above, one who can receive (but not transmit) is a scanner operator. ar-wiki
SWR Standing Wave Ratio - Measurement of forward vs. reflected power output during transmit. icom
SWR Standing Wave Ratio, a measure of how much radio energy sent into an antenna system is being reflected back to the transmitter dslreports
SWR Standing Wave Ratio, a measure of how much radio energy sent into an antenna system is being reflected back to the transmitter. eham.net
SWR Standing Wave Ratio; an indication of how well matched an antenna is to its transmitter. A "one to one" (1:1) SWR indicates a perfect match. Anything less than 1:1 (i.e., 2:1) indicates that the antenna is not perfectly resonant for the transmit frequency, and that some RF power is being reflected back down the transmission line into the transmitter. In general, any SWR which is 3:1 or better is acceptable. qrz.com
SWR Standing Wave Ratio. The ratio of the height of a standing wave on a transmission line to the height of an adjacent node. ar-wiki
SWR meter a device used to determine the Standing Wave Ratio of an antenna system dslreports
SWR Meter A measuring instrument that can indicate when an antenna system is working well. hamuniverse
T pad one of the possible configurations used in Attenuators ar-wiki
Tactical Communications Names used to identify a location or function during local emergency communications. hamuniverse
Talk-Around Same as "Simplex" (see definition above). qrz.com
TCXO Temperature Compensated Crystal Oscillator - Heated crystal oscillator for better frequency stability. icom
Telegraphy text based modes. Includes morse and RTTY. ar-wiki
telegraphy the transmission of information in Morse code format dslreports
telephony the transmission of information in voice format dslreports
Teleprinter A machine that can convert keystrokes (typing) into electrical impulses. The teleprinter can also convert the proper electrical impulses back into text. Computers have largely replaced teleprinters for amateur radioteletype work. hamuniverse
Temperature Inversion A condition in the atmosphere in which a region of cool air is trapped beneath warmer air. hamuniverse
Terminal An inexpensive piece of equipment that can be used in place of a computer in a packet radio station. hamuniverse
Thermionic Valve (Also known as an Electron Tube or a Vacuum Tube). A device that creates or modifies an electrical signal through the movement of electrons in a low pressure (vacuum) space. ar-wiki
third-party communications messages passed from one amateur to another on behalf of a third person dslreports
third-party communications messages passed from one amateur to another on behalf of a third person. eham.net
Third-Party Communications Messages passed from one amateur to another on behalf of a third person. hamuniverse
THROB An MFSK digital mode based on tone pairs. ar-wiki
TI Talk-In Frequency dslreports
Ticket Slang for "FCC License" qrz.com
ticket slang for an amateur radio license dslreports
ticket slang for an amateur radio license. eham.net
TNC 1)Terminal Node Controller - Modem for data communication. - 2) A type of antenna connector. icom
TNC Terminal Node Controller - a device used in packet radio that disassembles and re-assembles packets of data. ar-wiki
TNC Terminal Node Controller, a device which interfaces a computer to a transceiver and performs a function similar to a modem dslreports
TNC Terminal Node Controller, a device which interfaces a computer to a transceiver and performs a function similar to a modem. eham.net
TNC Threaded Niell-Concelman (standard connector type used on Coax cable, named for its inventors) dslreports
tone pad an array of 12 or 16 numbered keys that generate the standard telephone dual tones dslreports
top band 160 Meter Ham Band (highest number meter band) dslreports
TOR Telex over radio dslreports
TOR (Teleprinting Over Radio) Used in three digital modes: AMTOR, PACTOR and G-TOR. ar-wiki
Toroid A donut-shaped solid usually constructed of ferrite, used as the former for transformers and inductors' ar-wiki
TOT Time Out Timer - Time limiting function for continued repeater or other operations. icom
Towers Antenna support structures. icom
traffic a message or messages sent by radio dslreports
traffic a message or messages sent by radio. eham.net
transceiver a radio that both transmits and receives dslreports
transceiver a radio that both transmits and receives. eham.net
Transceiver A radio that has both a transmitter and a receiver, which either share common circuitry or a common housing or both. ar-wiki
Transceiver A radio transmitter and receiver combined in one unit. hamuniverse
Transient A short spike or trough on a power line, usually lasting for a few microseconds. ar-wiki
Transistor See "P-N Junction". qrz.com
Transmission Line Also known as feedline. ar-wiki
Transmitter A device that produces radio-frequency signals. hamuniverse
Transverter A device similar to a downconverter, but used for both receive and transmit. icom
Troposphere The region in Earth?s atmosphere just above the Earth?s surface and below the ionosphere. hamuniverse
Tropospheric Bending When radio waves are deformed in the troposphere, they return to Earth farther away than the visible horizon. hamuniverse
Tropospheric Ducting A type of VHF propagation that can occur when warm air overruns cold air (a temperature inversion). hamuniverse
TS Tuning Step - Incremental steps icom
TSQL Tone SQueLch - Squelch function using subaudible tones, selective call. icom
Tuned Circuit A capacitor and an inductor, usually in parallel. The circuit responds strongly at its resonant frequency and is used to select or tune in wanted signals. ar-wiki
TVI Interference to television reception. ar-wiki
TVI TeleVision Interference icom
TVI Television interference. eham.net
twisted pair ham slang for telephone or telephone lines dslreports
two-tone test A method of testing a side-band transmitter dslreports
TWT Traveling Wave Tube, found in microwave amplifier circuits. icom
TX Abbreviation for "transmitter" or "transmit" qrz.com
TX Abbreviation for transmit or transmission ar-wiki
TX Transmit icom
U CW abbreviation for "you" ar-wiki
UFB CW abbreviation for "Ultra Fine Business" or "excellent" ar-wiki
UHF Ultra High Frequency - 300 MHz-3 GHz range signals. icom
UHF Ultra High Frequency 300 - 3000 MHz dslreports
UHF Ultra High Frequency. Frequencies in the range 300MHz to 3 000MHz ar-wiki
UHF connector A threaded co-axial RF connector (PL-259, SO-239) originally designed in the 1930's for use at frequencies in the 30-300MHz range. (These frequencies are now considered to be VHF.) Most commonly used in amateur radio stations to make RG-8 or RG-213 cable connections to HF transceivers. ar-wiki
UHF connector Sometimes called a PL-259 plug, for coaxial cable, on VHF. icom
Uncle Charlie The FCC dslreports
Uncontrolled Environment Any area in which an RF signal may cause radiation exposure to people who may not be aware of the radiated electric and magnetic fields. When a pedistrian walks by your mobile radio, he is in an uncontrolled environment as an example. He is not aware of the rf radiation coming from your antenna when you are transmitting but is being subjected to rf exposure. hamuniverse
Uplink [vs. Downlink] - Frequency that user transmits to the repeater or satellite. icom
uplink Channel used for earth-to-satellite communications dslreports
UR CW abbreviation for "your" ar-wiki
USB (1) Upper Sideband, used primarily for single sideband operation above 10MHz ar-wiki
USB (2) Universal Serial Bus, an interface to desktop PC peripherals ar-wiki
USB 1) Upper Side Band - 2) Universal Serial Bus icom
USB Upper Side Band the common single-sideband operating mode on the 20, 17, 15, 12, and 10 meter HF amateur bands, and all the VHF and UHF bands. eham.net
USB Upper Side Band common for the 20, 17, 15, 12, and 10 meter HF amateur bands, VHF and UHF bands dslreports
USB Upper Sideband qrz.com
UTC Coordinated Universal Time dslreports
UTC Coordinated Universal Time; a single time reference to be used worldwide (reduces the confusion that can occur when considering multiple time zones). qrz.com
UTC Coordinated Universal Time. A corrected - using atomic clocks- version of GMT ar-wiki
UTC Universal Time Coordinated - An astronomical time based on the Greenwich meridian (zero degrees longitude). icom
utility stations Stations other than broadcast, or amateur stations not intended to be heard by the public including aviation, radiotelephone, marine, embassy, and military dslreports
VA Volt Amperes - measure of apparent power dslreports
VA Volt Amperes - measure of apparent power. ar-wiki
VAC Volts Alternating Current dslreports
VAC Volts Alternating Current. ar-wiki
Vacuum Tube (Also known as an Electron Tube or a Thermionic Valve). A device that creates or modifies an electrical signal through the movement of electrons in a low pressure (vacuum) space. ar-wiki
Varactor Diode a component whose capacitance decreases as the reverse bias voltage is increased. ar-wiki
varactor diode a component whose capacitance varies as the reverse bias voltage is changed dslreports
VCO Voltage Controlled Oscillator, found in the PLL section of the modern radio. icom
VCO Voltage-controlled oscillator ar-wiki
VCO Voltage-controller oscillator dslreports
VDT Video Display Terminal hamuniverse
VE Volunteer Examiner, a person authorized to administer examinations for amateur radio licenses. eham.net
VE Volunteer Examiner, in countries in which government radio inspectors no longer conduct examinations for prospective new licensees but delegate this task to a few experienced radio amateurs. (Also: VE as a callsign prefix refers to the Dominion of Canada - so "W/VE stations" would indicate the continent of North America.) ar-wiki
VEC Volunteer Exam Coordinator. Examples include the ARRL (http://www.arrl.org) and W5YI (http://www.w5yi.org) qrz.com
VEC Volunteer Examiner Coordinator ar-wiki
VEC Volunteer Examiner Coordinator, an amateur radio organization empowered by the FCC to recruit, organize, regulate and coordinate Volunteer Examiners dslreports
Velocity Factor the speed at which radio waves travel in a particular feedline, expressed as a fraction of the speed of light ar-wiki
Vertical Polarization Used to describe a transmission or antenna in which the electric field is propagated perpendicular to the surface of the Earth. Antennas intended for two-way radio communication with mobile stations (where vertical antennas are common) typically use vertical polarization, while broadcast TV/FM signals are most often horizontally polarised. ar-wiki
VFO Variable Frequency Oscillator ar-wiki
VFO Variable Frequency Oscillator - An operation mode in which operator can change frequency freely. icom
VFO--Variable-Frequency Oscillator An oscillator used in receivers and transmitters. The frequency is set by a tuned circuit using capacitors and inductors. The frequency can be changed by adjusting the components in the tuned circuit. (The knob on your transceiver that changes your frequency). hamuniverse
VHF Very High Frequency - 30-300 MHz range signals. icom
VHF Very High Frequency 30 - 300 MHz dslreports
VHF Very High Frequency. Frequencies in the range 30MHz to 300MHz ar-wiki
VIS Vertical Interval Signalling. Digital encoding of the transmission mode in the vertical sync portion of an SSTV image. ar-wiki
Visible Horizon The most distant point on the earth one can see by line of sight. hamuniverse
VK Australia ar-wiki
VLCA Very limited coverage area. Typically used in reference to small portable repeaters deployed by emergency/disaster or public service groups to temporarily provide local communication within a relatively-small area. ar-wiki
VLF Very Low Frequency 3 - 30 KHz ar-wiki
VMOS Vertical metal-oxide semiconductor ar-wiki
VOA Voice Of America. dslreports
Volt (V) The unit of electric potential difference (Voltage) between two points. ar-wiki
Volt (V) The basic unit of electrical pressure or EMF. hamuniverse
Voltage The EMF or pressure that causes electrons to move through an electrical circuit. hamuniverse
VOM Volt-ohm-meter dslreports
VOX Voice Operated Relay; allows the presence of a sound to trigger the PTT. qrz.com
VOX Voice Operated transmission - A function that automatically switches the transmitter to transmit when you talk into the microphone. icom
VOX Voice Operated Transmit ar-wiki
VOX Voice Operated Transmit. eham.net
VSC 1) Voice Scan Control - 2) Voice Squelch Control icom
VSWR Voltage standing wave ratio ar-wiki
VTVM Vacuum tube voltmeter dslreports
VXO Variable crystal oscillator ar-wiki
VY CW abbreviation for "very" ar-wiki
W1AW Official ARRL station callsign, also transmits Amateur Radio News Bulletins, Propagation Conditions and Forecasts, and Morse Code Practice. Former Call of Hiram Percy Maxim, ARRL founder. dslreports
WAB Worked All Britain. ar-wiki
WAC Worked All Continents award from the IARU, administered by ARRL dslreports
WAC Worked All Continents; an award issued to those who make, and have proof of, contact to at least one ham on each continent. qrz.com
WAC Worked All Continents. ar-wiki
wallpaper QSL cards, awards, special event certificates dslreports
Wallpaper Slang for QSL Cards and operating/contest certificates. qrz.com
WAN Worked All Neighbors; a station that continually gets complaints about signals showing up on the telephone or televisions at neighbor's houses. Not a desired situation. Polite conversation and changes in operation practices are a common solution. Another is providing simple and often inexpensive filters for the offended neighbor. See the TVI solutions page at the ARRL web site for more information on cures (courtesy of K4GVN). qrz.com
WAN Worked All Neighbours. Used to refer to a powerful station in a densely-populated area where strong signals overload broadcast receivers in the immediate vicinity. ar-wiki
WARC World Administrative Radio Conference dslreports
WARC World Administrative Radio Conference; most commonly associated with the "WARC Bands", those bands added to the Amateur Radio band plan which include the 30, 17, and 12 meter HF bands. qrz.com
WARC World Administrative Radio Conference. Also used to reference the WARC bands 10, 12 and 17 meters. eham.net
WARC Bands Agreed to at the 1979 WARC, they consist of the 30m ( 10.100Mhz - 10.150MHz), 17m (18.086MHz - 18.186MHz) and 12m (24.890MHz - 24.990MHz) amateur bands. ar-wiki
WARC Bands An expression to indicate the bands allocated in 1979 - 17M, 12M and 30M dslreports
WARC, WRC World (Administrative) Radio Conference. Run by the International Telecommunications Union. ar-wiki
WAS Worked All States award from ARRL dslreports
WAS Worked All States; an award issued to those who make, and have proof of, contact to at least one ham in each U.S. state. qrz.com
WAS Worked All States. In the US, contacts with stations in each of the fifty US states. ar-wiki
Watt The unit of power in the metric system. hamuniverse
WAVE Worked All VE. Contacts with stations in each of the Canadian provinces. ar-wiki
Waveguide A hollow tube, typically square in cross-section, used to carry microwave signals. ar-wiki
Waveguide The carrier of microwaves from radio to antenna, and back. icom
Wavelength The distance an ac signal will travel during the time it takes the signal to go through one complete cycle. hamuniverse
Wavelength The distance in metres between corresponding points on a wave. ar-wiki
WAXE Worked All XE / México. ar-wiki
WAZ Worked All Zones award from CQ magazine for confirmed contact with each of 40 zones dslreports
Weather Alert NOAA broadcast station transmitting alert signals. icom
WEFAX Weather facsimile, reconstructed satellite images and photographs dslreports
WFM Wideband FM icom
WIA Wireless Institute of Australia. The national organisation for Australian hams. ar-wiki
wireless radio (As opposed to wired telegraph) dslreports
WKD CW abbreviation for "worked" ar-wiki
WOLF Weak-signal Operation on Low Frequency - for more information, see http://www.computerpro.com/~lyle/wolf/wolf4dummies.htm (courtesy of K?LR). qrz.com
Wouff Hong An instrument of sadistic torture for hams who do not follow generally accepted rules of courtesy on the air. It looks something akin to a Saguaro cactus with one arm missing (courtesy of AA7VP) Note: [the truth] The Wouff Hong sprang from the imagination of ARRL cofounder Hiram Percy Maxim, W1AW, as a means to combat poor operating. qrz.com
Wouff-Hong Mystical Ham Torture Device invented by "The Old Man"(T.O.M) 1AW ARRL founder Hiram Percy Maxim. dslreports
WPM Words per minute; as in Morse code or typing speed dslreports
WPM Words per minute; as in Morse code or typing speed. eham.net
WPM Words per minute. ar-wiki
WRK CW abbreviation for "work" ar-wiki
WSJT Weak Signal Joe Taylor - named after Joe Taylor who wrote the software. ar-wiki
WSPR Weak Signal Propagation Reporter. ar-wiki
WWV A radio station located in Fort Collins, Colorado, that continuously broadcasts standard time of day and other radio and navigation information. For more information, see http://www.lerc.nasa.gov/WWW/MAEL/ag/wwv.htm. qrz.com
WWV National Bureau of Standards radio station (time signals) dslreports
WWVB NIST radio station (broadcasts time signals) dslreports
WWVH A radio station located in Kauai, Hawaii, that continuously broadcasts standard time of day and other radio and navigation information. For more information, see http://www.chem.hawaii.edu/uham/wwvh.html. qrz.com
WX Abbreviation for "weather" qrz.com
WX weather dslreports
WX Weather. See weather spotting, APRS for transmission of current meteorological readings via amateur radio. Many 2 metre handheld transceivers are also capable of extended tuning to permit reception of forecasts over VHF bands assigned to other services, such as marine radio. ar-wiki
XCVR Transceiver ar-wiki
XCVR Transceiver (a unit integrating both a transmitter and a receiver). qrz.com
XCVR Transceiver. eham.net
XFMR Transformer dslreports
XIT The ability to shift the transmit frequency of a transceiver while maintaining a constant receive frequency. ar-wiki
XIT Transmit Incremental Tuning; a common feature on HF radios that allows the user to slightly change the transmit frequency while leaving the receive frequency the same. qrz.com
XTAL Crystal ar-wiki
XYL Ex-Young Lady, wife dslreports
XYL Short for "wife" (i.e. ex-YL) qrz.com
XYL Wife of an amateur operator. (A lady operator is referred to as YL - young lady.) ar-wiki
Yagi A directional antenna consisting of a dipole and at least two additional elements, a slightly longer reflector and one or more slightly shorter directors. Invented in 1926 by Hidetsugu Yagi and Shintaro Uda. ar-wiki
Yagi An antenna consisting of two or more elements ("arms" that run perpendicular to a common boom) which are fed parasitically from one or more "driven" elements. The number of elements is proportionate to the gain (more elements means more gain). qrz.com
Yagi beam directional antenna array dslreports
Yagi Directional antenna. icom
yagi in 1926 Hidetsugu Yagi and Shintaro Uda invented the "beam" antenna array. A directional antenna consisting of a dipole and two additional elements, a slightly longer reflector and a slightly shorter director. Electromagnetic coupling between the elements focuses maximum power (or reception) in the direction of the director. eham.net
YF short for "wife" qrz.com
YL Abbreviation for Young Lady, any female operator regardless of age or marital status. ar-wiki
YL Young Lady, any female amateur radio operator or the significant other of a amateur. eham.net
YL Young Lady; short for "girlfriend" qrz.com
Z code Three letter codes for use in military radio instead of sentences or phrases. An extension (not a replacement) of the existing Q Code, these added codes are not in use by any of the civilian services (amateur radio, aviation, marine) currently using Q code. ar-wiki
Zed A way of saying the letter "Z"; considered by many to be a more precise way of expressing that letter "Z"; prevents others from confusing "Z" with "E", "P", etc. qrz.com
zed phonetic for letter "Z" dslreports
Zener diode A diode used to regulate the operating voltage. icom
Zepp antenna simply a weighted wire reeled down and up from early lighter-than-Zeppelin air-ships dslreports
zero beat Adjust the frequencies of two signals so that they are exactly equal and in phase dslreports
Zero Beat one or both of two signals are adjusted so that they are identical and in phase. ar-wiki
ZL New Zealand. ar-wiki
Zulu (z) Another term for Coordinated Universal Time (UTC). Also known as GMT (Greenwich Mean Time) ar-wiki
Zulu Coordinated Universal Time. Also the phonetic for the letter Z dslreports
Zulu Often used to refer to UTC (see above), as in "Zulu Time". qrz.com

Sources:

icom http://nyc-arecs.org/icom_terms.pdf
ar-wiki http://www.amateur-radio-wiki.net/index.php?title=Dictionary_of_Ham_Radio_Terms
dslreports http://www.dslreports.com/faq/15711
eham.net http://www.eham.net/newham/glossary
hamuniverse http://www.hamuniverse.com/hamradiodefinitions.html
qrz.com https://www.qrz.com/page/hamspeak.html