Radio Term

Radio Term

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

AMSAT

AMateur SATellite

AMTOR

(AMateur Teleprompting 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 ohm 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

ARRL

The American Radio Relay League

The National Association for Amateur Radio in the US.

ASCII

American National Standard Code for Information Interchange

ATT

(ATTenuator) A network designed to reduce the amplitude of a signal.

ATV

Amateur Television

FSTV

Fast Scan TeleVision

SSTV

Slow Scan TeleVision

Auto patch

Used in repeater operation for telephone interconnect.

Average power

Power measured on standard power meter.

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.

Bandwidth

Frequency needed for particular type of emission.

Bank

Memory bank

BCI

BroadCast Interference

BFO

Beat Frequency Oscillator

BNC

Bayonet Neill-Concelman a type of antenna connector

BPF

BandPass Filter

Boat Anchor

A term used to describe any heavy, big, old, Ham Radio gear can be woking or nonworking condition

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 Clock Wise

CH

(CHannel) Sequence of memory positions where frequency and related information is stored.

CPU

Central Processing Unit

Copy

A term used to indicate a good readable signal

CQ

Radio communications term used to call others.

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.

Cycle

See Khz, Mhz. Ghz

CW

Carrier Wave or Continuous Wave. Most Commonly Used With Morse Code Communi-cations

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 OHM (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 121.5 MHz.

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. Feature reduces unwanted signal noise

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.

Dual watch

Receiving two signals simultaneously.

Dummy load

A non radiating 50 ohm 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.

Duty cycle

The ratios of transmit to receive time.

Dx’pedition

Trip to foreign land to “be DX.”

Ears

You Hams Catch this One? (think its some kind of antenna?)

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

Elmer

A mentor in ham radio, or the ham that helped you get started in ham radio.

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.

Fading

Signal reduction due to atmospherics.

Filter

A circuit designed to pass only the desired frequency(s).

FM

1) Frequency Modulation
2) FM broadcast

Freeband or FREE BAND

(A section of frequency that was claimed by renegades from the C.B. band between 27.405 to 28.000 Mhz.) Also see “Sub Band” 26.965 Mhz. And below!.

Frequence

Hz (Hertz)
Khz (Hertz) x-Thousand
Mhz (Mega Hertz) x-Million
Ghz (Giga Hertz) x100-Million

FSK

Frequency Shift Keying

FSTV

(Fast Scan TV) Graphics (and audio) communication using TV broadcast signals, requires a wide bandwidth.

Full duplex

An operation mode, which transmits and receives on different frequencies at the same time, as a telephone communication.

GMT

Greenwich Mean Time (see UTC, Zulu Time) an astronomical time based on the zero time/degrees longitude for different.

Ground Plane

A type of Omni-directional antenna

Ground Wave

Electrical wave directly travelling from transmitter.

Grounding

Electrical connection to the earth.

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

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.

IMD

(Inter-Modulation Distortion) Distortion within RF circuits made with upper and lower adjacent channel signals.

In The Dirt

An indication that the signal being received is weak or poor, and is just making it over the noise level.

KEY

A device used to send Morse Code.

Keyer

A device used to send Morse Code that automates the process of sending individual “Dots and Dashes”

KICKER

Just to see if all you Hams are reading down this far! (Big Amp I Think? 4KW)

LF

(Low Frequency) 30–300 kHz range signals.

Li-Ion

(Lithium Ion)

Rechargeable battery which has better capacity than Ni-Cd,

Lid

A radio operator who is causing intentional problems on the air

LPF

Low Pass Filter

LSB

Lower Side Band

MARS

Military Affiliate Radio Service(No Not The Planet)

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

MIC

MICrophone

Mod or Mod’s

Modifications done to radios to get EXTRA features Common to Hams

Modulation

Method of adding information to a radio frequency carrier

Morse Code

A form of communication also known as CW

Net

A term used meaning a group of hams all on the same frequency, at the same time, taking part in an organized or structured meeting.

Net Control

The individual conducting or managing the net.

Ni-MH, etc

no memory effect after repeated non-full charge / discharge cycles.

Ni-MH

Nickel-Metal Hydride

NB

Noise Blanker a function reducing pulse-type noises.

NBFM

Narrow Band FM

Ni-Cd

Nickel-Cadmium

NOAA

(National Weather Service) NOAA Broadcast station transmitting weather related alert signals.

Notch filter

Sharp and narrow rejection filter for elimination of interfering Signals

NR

Noise Reduction

Offset frequency

Frequency difference between transmits and receives.

OSC

OSCillator

Over Modulated

Common Practice on sound from speker received,

PA

Power Amplifier

PBT

(PassBand Tuning) A function electronically reduce interference by narrowing IF Bandwidth

PEP

Peak Envelope Power

Picket Fencing

A term used to describe a signal that is cutting in and out, or hard to copy.

PLL

(Phase Locked Loop) Circuit to synthesize the different frequencies a radio will operate on.

PTT

Push To Talk as hand microphone

PWR

(PoWeR) On – Off Switch

Rag Chew

A Ham who likes to talk for a long time!

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.

RF

Radio Frequency

RF Power

Power at maximum amplitude.

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.

Rodger “Beep”

An annoying device used by some people to cause splatter! (see splatter)

RTTY

Radio TeleTYpe

RX

Receive

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.

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.

Simplex

An operation mode where transmit and receive frequency is same.

Sky Warn

Trained volunteer storm spotters for the National Weather Service.

SMA

(Sub-Miniature a connector) Type of antenna connector, used in VHF/UHF portable.

SP or SPK

Speaker

Splatter

A term used to describe excessive distorted,or dirty RF siginal

Split or Offset

(+ 0r -)

A mode in which the transmit and receive frequency is different. Commenley used in UHF – VHF Repeater Operation.

SQL

(SQueLch) A function muting audio output for set conditions.

SSB

Single Side Band it has 2 type :

1) USB (Upper Side Band)

2) LSB (Lower Side Band)

SSTV

(Slow Scan TV) Graphics communication using narrow bandwidth.

SWL

Short Wave Listener

SWR

(Standing Wave Ratio) Measurement of forward vs. reflected power output during transmit.

TCXO

(Temperature Compensated Crystal Oscillator) Heated crystal oscillator for better frequency stability.

TNC

1) Terminal Node Controller Modem for data communication.
2) A type of antenna connector

TOT

(Time Out Timer) AKA Alligator got ya! Time limiting function for continued repeater or other operations.

Traffic

Is a term used meaning news or Information of some type

TS

(Tuning Step) Incremental steps

TSQL

(Tone SQueLch) Squelch function using subaudible tones, selective call.

TVI

(TeleVision Interference) CB’ers know about this one well!

TX

Transmit

UHF

(Ultra High Frequency) 300 MHz–3 GHz range signals.

Uplink (?Downlink)

Frequency that user transmits to the repeater or satellite.

USB

1) Universal Serial Bus (If not modulation)
2) Upper Side Band (Modulation)

UTC

Universal Time Coordinated (see GMT, Zulu Time) an astronomical time based on the zero time/ degrees longitude for different.

UFO

What a Ham swears he saw a few beers and a long night at Field Day

VFO

(Variable Frequency Oscillator) An operation mode in which operator can change frequency freely.

VHF

(Very High Frequency) 30–300 MHz range signals.

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 weather related alert signals.

WFM

Wideband FM

Zulu Time

(see : UTC or UTC) an astro-nomical time based on the zero time/degrees longitude for different.