222 MHz, The ham band between 222 and 225 MHz.
2-Meter Band, The ham band between 144 and 148 MHz.
6-Meter Band, The ham band between 50 and 54 MHz , the lowest frequency VHF ham band.
70-cm Band, Also known as "440," the amateur band extending from 420 and 450 MHz.
73, Ham lingo for "best regards." Used on both phone and CW toward the end of a contact.
ACC (ACCessory)
Adjacent-channel interference, When a receiver is tuned to a specific frequency and interference
is received on a nearby frequency.
AF (Audio Frequency)
AFC (Automatic Frequency Control) Automatically compensate frequency drift.
AFSK (Audio Frequency Shift Keying)
AGC (Automatic Gain Control) Automatically optimize receiver amplifier gain.
ALC (Automatic Limiting Control) Limits RF drive level to power amplifier during transmit to
prevent distortion.
AM (Amplitude Modulation) A radio transmission mode; except for some AM activity on 6 meters, you'll generally find only a type of AM, called Single Sideband (SSB), used on VHF.
Amateur Operator, A person holding a written authorization to be the control operator of an amateur station.
Amateur Radio Service, A radiocommunication service for the purpose of self-training, intercommunication and technical investigations carried out by amateurs, that is, duly authorized persons interested in radio technique soley with a personal aim and without pecuniary interest. (Pecuniary means payment of a type, whether money or goods.)
Amateur Station, A station licensed in the amateur service, including necessary equipment, used for amateur communication.
AMSAT (AMateur SATellite)
Amateur Satellites, An international fleet communications satellites carrying amateur radio stations (See OSCAR).
AMTOR (AMateur Teleprinting Over Radio) A form of RTTY, radio teletype.
ANF (Automatic Notch Filter)
ANL (Automatic Noise Limiter) Eliminates impulse and static noise peaks.
ANT (ANTenna)
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.
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 ohms for most transceivers.
Antenna matching, When the antenna's impedance at resonance is at optimum performance for your transmitter output circuit.
Antenna tuner, Device used to match an antenna to the output impedance of a transmitter.
APC (Automatic Power Control) Current limiting of power amplifier to prevent damage to finals in high SWR conditions.
APRS (Automatic Position Reporting System) In conjunction with a GPS and TNC provide position reporting.
ARES (Amateur Radio Emergency Service) ARES is a public-service organization of the ARRL.
ARRL, (American Radio Relay League) The ARRL is the membership organization of Amateur Radio operators in the United States. Formed by Hiram Percy Maxim, along with several hundred amateurs from across the country. The ARRL represents the interests of Amateur Radio in Washington. The ARRL makes sure the FCC and other government agencies know where U.S. amateurs stand on current events.
ASCII (American National Standard Code for Information Interchange) A seven-unit digital code for the transmission of teleprinter data
ATT (ATTenuator) A network designed to reduce the amplitude of a signal.
ATV (Amateur Television) FSTV, SSTV
Auto patch, Used in repeater operation for telephone interconnect. A component which allows telephone calls to be placed through a repeater.
Average power, Power measured on standard power meter.
Az/El, (Azimuth and Elevation) When you are aiming an antenna at a satellite or other object in the sky, you need to set the azimuth heading (compass bearing) as well as the angle of elevation above the horizon. An az/el rotator will perform both functions.
Backscatter, Form of ionosphere propagation via the E and F layers allowing stations to hear other stations within the skip zones.
Balun, A simple transformer used to change an unbalanced input to a balanced output.
Band, A range of frequencies.
Band Opening, A condition that results in greater than-normal communications range on the VHF and UHF amateur bands.
Band Plan, A voluntary system of frequency allocations for each amateur radio band.
Bandwidth, Frequency needed for particular type of emission. The width of a signal on the radio spectrum. The greater a signal's bandwidth, the more frequency space it occupies.
Bank, Memory bank
BCI (BroadCast Interference)
BFO (Beat Frequency Oscillator) A variable pitch tone oscillator, used mostly on older style radios, to permit reception of single sideband and Morse code signals on an AM receiver.
BNC (Bayonet Neill-Concelman) A type of antenna connector
BPF (BandPass Filter)
Busy lockout, Inhibits transmit on a frequency in use
Call sign, Sequence of letter and numbers used to identify amateur radio operators and issued by the FCC.
CAP (Civil Air Patrol) Volunteer affiliate of the United States Air Force.
Carrier, An unmodulated transmitted signal.
Carrier frequency offset, (=Carrier Shift) Distance between mark and space of the carrier for RTTY or similar communications.
CBR (Cross Band Repeater) A repeater which receive incoming signal and re-transmit it in different bands- e.g. receives 144 MHz bands and re-transmits 430(440) MHz bands.
CCW (Counter ClockWise)
CH (CHannel) Sequence of memory positions where frequency and related information is stored.
CI-V, Icom computer Control Interface allows multiple radio control simultaneously.
Controller, The "brain" of a repeater. Among its many possible functions are turning the repeater on and off, timing transmissions, sending the repeater's identification signal, and controlling the autopatch and CTCSS encoder/decoder.
Conversion, Number of IF circuits in the receiver.
Courtesy Tone, An audible signal transmitted by a repeater which lets users know that the repeater has reset at the end of one person's transmission and is available for use by the next person.
CPU (Central Processing Unit)
CQ, Radio communications term used to call others.
Crossband Repeater, A repeater whose input and output frequencies are on two different bands. For example, a signal received on 70 centimeters would be retransmitted on 2 meters, and vice versa. Many dual-band FM rigs include this feature.
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. Also called sub-audible tones or "PL" tones (trademarked name by Motorola). This is the tone which is transmitted by your radio in addition to your voice signal. When it is equipped with a CTCSS decoder, a repeater will not function unless it hears both the CTCSS tone and the "carrier" signal from your radio.
CW, (Continuous Wave) The FCC emission type that describes international Morse code telegraphy communication without audio modulation of the carrier. Amateurs usually produce Morse code signals by interrupting the continuous-wave signal from a transmitter to form the dots and dashes. This is ON/OFF keying of a radio-frequency signal. Another name for International Morse Code.
CW, (ClockWise)
CW filter, Used to narrow IF passband to improve reception in crowded band conditions.
Data communications, Transfer of data between two or more locations.
dBd, Unit of RF power as compared to a dipole antenna.
dBi, Unit of RF power as compared to an isotropic antenna.
dBm, Decibels measure, 1 mW with a load impedance of 600 ohms (0dBm=1 mW).
DC (Direct Current)
DC ground, A connection point directly to chassis or battery ground to prevent build-up of hazardous DC voltages.
Deviation, A measurement for a FM signals for the maximum carrier frequency changes either side of the carrier frequency.
Distress call, Signals a life-threatening situation. Most commonly referred to as an SOS or MAYDAY call.
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.
Downlink (<-> Uplink) Frequency that repeater or satellite transmits on to a user.
DSP (Digital Signal Processor) Used to improve the signal to noise ratio for clearer and more legible communications. Relatively new to the ham radio.
DTCS (Digital Tone Coded Squelch) A Selective call system
DTMF (Dual Tone Multi-Frequency (=touch-tone)) Used for transmit/receive numeric information such as phone number, PIN, remote radio control commands etc. A tone signaling system used in push-button telephones and many ham rigs. Commonly known by AT&T's trade name "Touch-Tone".
Dualwatch, Receiving two signals simultaneously.
Dummy load, A non radiating 50 ? load connected to the transmitter to replace the antenna for testing purposes.
Duplex, An operation mode in which the transmit and receive frequencies are different.
Duplexer, A device which divides transmit and receive signals. Highly selectable, tunable filters which allow a repeater's transmitter and receiver to use one common antenna.
Duty cycle, The ratios of transmit to receive time.
Dx'pedition, Trip to foreign land to "be DX."
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.
EEPROM (Electrically Erasable and Programmable Read Only Memory)
EME (Earth-Moon-Earth) Moon bounce communication.
EMI (Electro-Magnetic Interference) Often called RFI (Radio-Frequency Interference).
Emission, Transmission of a signal
Encryption, Transmitting cryptic form so that only certain people understand what has been sent.
FCC, (Federal Communications Commission) A govenment body that regulates the amateur radio hobby with rules and regulations. It controls the standards of operating procedures for an amateur radio station. It also issues the license for the operation of a amateur radio station as well as for the operators license. Mainly the part of the government which oversees the operation of most communications in the United States.
Fading, Signal reduction due to atmospherics.
Filter, A circuit designed to pass only the desired frequency(s).
FM, 1) Frequency Modulation 2) FM broadcast, The radio transmission mode used for most VHF amateur communications.
FSK (Frequency Shift Keying)
FSTV (Fast Scan TV) Graphics (and audio) communication using TV broadcast signals, requires a wide bandwidth.
Frequency Band, A group of frequencies designated by government regulation for a specific purpose. Bands reserved for use by amateurs are called "amateur bands" or "ham bands".
Full duplex, An operation mode, which transmits and receives on different frequencies at the same time, as a telephone communication. Simultaneously receiving and transmitting on one radio. Normally, the receiver is muted during transmit to avoid feedback. In full-duplex operation, the receiver stays active, but is generally tuned to a different frequency or, most often a different band.
Gateway, A link, or bridge, from one type of communication network to another.
GHz, (GigaHertz) : A unit of frequency measurement (1 GHz = 1,000 MHz).
Ground Plane, A type of Omni-directional antenna
Ground Wave, Electrical wave directly travelling from transmitter.
Grounding, Electrical connection to the earth.
Handheld, An amateur radio transceiver that's small enough to be carried in your hand (often abbreviated "HT"). Typically, amateur handhelds are for VHF/UHF use.
Harmonic, Multiple of a fundamental frequency.
HF (High Frequency) 3-30 MHz range signals. (Normally, 1.9 MHz band also included.)
HPF (High Pass Filter)
Hz (Hertz) The basic unit of frequency measurement (cycles per second).
IC (Integrated Circuit)
IF (Intermediate Frequency) Internally converted frequency for amplification and other signal processing.
IF shift, A function that electronically shifts IF frequency from a center frequency.
Intermod or IMD, (Inter-Modulation Distortion) Distortion within RF circuits made with upper and lower adjacent channel signals. Interference that results when strong signals from a nearby transmitter mix with the desired signal in a radio receiver.
Impendance, A measure of resistance to the flow of RF energy (see below) based on a combination of actual electrical resistance in the wire of a feedline or antenna (resistance) and losses due to inefficiency in the feedline or antenna wire or a mismatch between the two (reactance). Just to confuse matters, resistance, reactance, and impedance are all measured in ohms. most ham transmitters work best into an antenna system with an impedance of 52 ohms. Ideally, you'll use 52 ohm feedline (such as RG-8) to an antenna with an impedance of 52 ohms at it's "feedpoint", the point where you feed in the signal through the feedline.
Input Frequency, The frequency on which a repeater receives and the one on which you transmit to the repeater.
Keplerian Elements, (Keps) A collection of data relating to the position of a satellite in it's orbit at any given time.This information is interpreted by satellite tracking programs to predict time and duration of satellite "passes" and direction in which to point antennas. Named for the 19th century scientist Johannes Kepler.
kHz, (kiloHertz) A unit of frequency measurement ( 1kHz = 1,000Hz ).
LCD, (Liquid Crystal Display) A type of display used on many radios and other electronic devices. Characteristics include dark (usually black) numbers and letters on a lighter background.
LF (Low Frequency) 30-300 kHz range signals.
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.
LPF (Low Pass Filter)
LSB (Lower Side Band)
MARS (Military Affiliate Radio Service)
Memory bank, A set of memory channels organized into a group.
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.
MF (Medium Frequency) 300 kHz-3 MHz range signals
MHz, (MegaHertz) A unit of frequency measurement ( 1MHz = 1,000 kHz ).
MIC (MICrophone)
Modulation, Method of adding information to a radio frequency carrier
NB (Noise Blanker) A function reducing pulse-type noises.
NBFM (Narrow Band FM)
Ni-Cd (Nickel-Cadmium)
Ni-MH (Nickel-Metal Hydride)
NOAA, (National Oceanic and Atmospheric Administration) Parent agency of the National Weather Service. (NOAA Weather Radio is a 24-hour-a-day weather reporting service, using several frequencies in the 162 MHz range).
Notch filter, Sharp and narrow rejection filter for elimination of interfering signals
NR (Noise Reduction) DSP feature reduces unwanted signal noise
Offset frequency, Frequency difference between transmits and receives. The difference between a repeater's input and output frequencies. The offset for 2-meters is generally 600 kHz.
OSCAR, (Orbiting Satellite Carrying Amateur Radio) Acronym describing amateur satellites generally; with a number attached (e.g., AMSAT-OSCAR-16, or AO-16), the name of a specific ham radio satellite.
OSC (OSCillator)
Output Frequency, The frequency on which a repeater transmits, and the frequency to which you tune your radio.
PA (Power Amplifier)
Packet, Common short form of "packet radio" , also the actual information package sent in in a packet radio transmission.
Packet Radio, The most popular form of amateur radio digital communications, in which computers hooked to radios exchange data in packets.
PACSAT, (PACket SATellite) Amateur satellite used to store and forward digital (packet radio) messages.
Parawatch (=Dualwatch)
PBT (PassBand Tuning) A function electronically reduce interference by narrowing IF bandwidth
PEP (Peak Envelope Power)
Propagation, The means by which radio signals are carried from one location to another.
RF, power at maximum amplitude.
PL, A trademarked name by Motorola. Has the same meaning as CTCSS.
PLL (Phase Locked Loop) Circuit to synthesize the different frequencies a radio will operate on.
Pocket beep, Beeping function when specific signal is received.
Priority watch, Reception mode, which by a selected frequency is always periodically, checked when VFO is set to different frequency
PTT (Push To Talk)
PWR (PoWeR)
RF (Radio Frequency) The radio waves generated by your transmitter (as well as your computer, your cordless phone , etc. ) are, not surprisingly, within the "radio" portion of the electromagnetic spectrum. Energy produced at these "radio frequencies" is called "RF" or "RF energy".
Reflected power, Non-radiated power dissipated as heat when the transmitter is mismatched to the antenna or load.
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. An automatic relay station. generally in a high location, which is used to increase the range of handheld and mobile FM transmitters.
Repeater Control Operator, A licensed amateur designated by a repeater trustee who offers assistance with autopatch and listens for inappropriate use of the repeater. (This is different from the FCC's definition of a control operator, which is anyone in control of an amateur transmitter).
Repeater Directory, A listing of repeaters in a given area. Typically, a repeater directory shows a repeater's location, the output frequency, the offset, and whether or not a CTCSS code is required.
Repeater Pair, Each repeater requires two frequencies : an input and an output frequency.
RF ground, Connection of amateur equipment to earth ground to eliminate hazards from RF exposure and reduce RFI.
RFI (Radio Frequency Interference)
RIT (Receiver Incremental Tuning) Fine-tuning receive frequency without changing displayed or memory frequency.
RTTY (Radio TeleTYpe)
Rubber Duck, Common term for the flexible rubber-covered antenna generally supplied with handheld radios.
RX (Receive)
S-Meter, A meter that provides a rough indication of received signal strength. ( Actually, an s-unit is a rather precise mesure, determined by mathematical formula. but it's the rare radio that's calibrated accurately enough for the numbers to be anything more than a rough measure).
S/N (Signal to Noise ratio)
SAR (Search And Rescue )
Scan, Continually sweeping frequencies looking for signals.
Scan Edge, End and start frequencies for a scanning range.
Scratch Pad Memory, Temporary frequency memories for quick access.
Semi Duplex, An operation mode in which transmits and receives is accomplished on different frequencies alternatively.
Sensitivity, Indicates how weak a signal the receiver will pick up.
Set mode, An operation mode used for radio. To set less frequently used control features.
Simplex, An operation mode where transmit and receive frequency is same. Generally used among FM operators to refer to making direct contacts without the use of repeaters. Frequencies set aside for simplex contacts (such as 146.52 MHz ) are often referred to as "simplex frequencies".
Signal Report, A report given in numerical values of signal strength and quality.
Skywarn, Trained volunteer storm spotters for the National Weather Service.
SMA (Sub-Miniature a connector) Type of antenna connector, used in VHF/UHF portable.
SP (SPeaker)
Split, A mode in which the transmit and receive frequency is different.
Squelch or SQL A function muting audio output for set conditions. A control on a radio that keeps the speaker silenced (squelched) until the signal level exceeds a certain point. Normally, you set the squelch to block out noise and allow signals to pass.
SSB (Single Side Band) A type of AM transmission which occupies less bandwidth than a standard AM signal.
SSTV (Slow Scan TV) Graphics communication using narrow bandwidth.
Sub-Audible Tone, Another term for CTCSS.
SWL (Short Wave Listener)
SWR (Standing Wave Ratio) Measurement of forward vs. reflected power output during transmit.
Tail, Most repeaters continue to transmit for a brief period after someone stops talking. This extra transmission is called a repeaters "tail".
TCXO (Temperature Compensated Crystal Oscillator) Heated crystal oscillator for better frequency stability.
Timer, A component in a repeater system that measures transmission length. The timer is set to a pre-determined length.
TNC, 1) Terminal Node Controller Modem for data communication, The "box" that goes between the computer and the radio in a packet station. 2) A type of antenna connector
TOT (Time Out Timer) Time limiting function for continued repeater or other operations.
TS (Tuning Step) Incremental steps
TSQL (Tone SQueLch) Squelch function using subaudible tones, selective call.
TVI (TeleVision Interference)
TX (Transmit)
UHF (Ultra High Frequency) 300 MHz-3 GHz range signals. The region of the radio spectrum between 300 and 3,000 MHz ( 3 GHz )
Uplink (<-> Downlink) Frequency that user transmits to the repeater or satellite.
USB (Upper Side Band) Every AM signal has two side-bands , upper and lower. In single sideband (SSB) , only one is transmitted. USB is used on VHF ( See AM and SSB )
UTC (Universal Time Coordinated) An astronomical time based on the Greenwich meridian (zero degrees longitude).
VFO (Variable Frequency Oscillator) An operation mode in which operator can change frequency freely. A general term used to describe the device on a radio that lets you move progressively higher or lower in frequency by turning a dial or pressing a key. Today's digitally-synthesized radios usually use a tunable phase-locked loop (PLL) instead of a true VFO.
VHF (Very High Frequency) 30-300 MHz range signals.
VHF Contest, An on-air competition in which activity is encouraged on VHF and UHF bands.
VOX (Voice Operated transmission) A function automatically put the transmitter in transmit when talk into a microphone.
VSC, 1) Voice Scan Control 2) Voice Squelch Control
Weather Alert, NOAA broadcast station transmitting alert signals.
WFM (Wideband FM)
For more information about Amateur Radio get the "Now You're Talking Book" from Radio Shack