10-meters: 28.0-29.7MHz

15-meters: 21.0-21.450MHz

20-meters: 14.0-14.350MHz

40-meters: 7MHz to 7.3MHz

80-meters: 3.5-4.0MHz

160-meters: 1.8-2.0MHz

(+): positive (power supply input)

(-): negative (power supply input)

A3A: Mode of single sideband with -16dB pilot carrier

A3H: AME or AM compatible (carrier with only upper sideband)

A3J: Telephony; single sideband with suppressed carrier

AGC: Automatic gain control which prevents receiver overload

ALC: Automatic loading control which prevents transmitter overload

AMP: Amplifier

AMTOR: Amateur radio equivalent of SITOR with slightly different standards

ATTN: Attenuator which reduces a received signal

ADSP: Adaptive Digital Signal Processing; exclusive to SGC, a DSP technology which processes the signal to eliminate unwanted noise and improve incoming signal sound clarity

AM: Amplitude modulation, low efficiency type of radio transmission generally used for broadcast AM radio station bands with 100% carrier inserted

AMVER: Coast Guard operated system for rescue "automated mutual assistance vessel rescue system"

AM broadcast band: A band ranging from 530 to 1605 KHz.

Amateur bands: HF frequencies of 1.8MHz to 29.7 MHz set aside for amateur radio operators.

Amplitude: The height of a radio or sound wave "loudness".

Amplitude Modulation: Adding information to an RF carrier by increasing and decreasing amplitude.

Analog: Representing data with physical quantities (a watch with hour and minute hands is an analog time display).

Antenna: Any part of any SSB system that radiates radio energy

ARQ: Automatic Repeat Request; a mode to compare transmission; a repeat signal is sent only when requested by the receiving station

Band: A range of frequencies, usually within a one MHz span

Bank: A collection of channels to be scanned as a group in order

Binary: A system of numbers represented only by digits 0 and 1. (Contrast with decimal which uses digits 0 through 9.)

Capacitor: A device to store electrical energy.

Carrier: An unmodulated RF signal.

CHAN: Channel

Chassis GND: Chassis or cabinet ground

CLAR: Clarifier; allows receiver frequency to be offset slightly from transmitter frequency

COMM: Communication; also used to reference serial communications computer port

CW: Continuous wave; to transmit the mode of Morse code

Crystal: A piece of quartz mineral that will resonate at a particular frequency and used as a reference in transceivers

COAX: Coaxial cable, an electrical conductor which carries radio energy from a transmitter to an antenna system; the inner conductor is insulated from an external wire mesh shield

Chip: A wafer of semiconductor material used in an electronic circuit.

Copy: When radio operators hear and write down a message, they "copy."

DATA I/O: Data input/output

DC: Direct Current

DUPLEX: A method of frequency in which ship stations transmit on one frequency while shore stations transmit a different frequency

DSP: Digital signal processing; technology which eliminates unwanted noise to enhances a signal

DXpedition: A trip taken by an amateur radio operator to a uniquie location, a contest to try to reach distant stations.

EMER: Emergency

FEC: Forward error correction; a mode to compare transmission; each character is sent twice and the redundancy of the code serves as the check

Feedline: The method of connecting the antenna to the radio

Frequency: The number of polarity alternations per second measured in Hertz. KHz = thousand Hertz; MHz = million Hertz

FM: Frequency Modulation

FWD: Forward transmit power going to the antenna

Gain: The amount of amplification a system has; in antenna systems, the gain is the measurement of the directional characteristics

GND: Ground

Ground: A connection to earth or an earth counterpoise, non-conductive

Groundplane: An artificial ground used for antenna systems

Groundwave: A radio signal that travels along the earth, bending over the horizon

GMT: Greenwich Mean Time (universal time) the international standard time referred to the zero degree meridian

Heterodyne: The frequency that results when two radio frequencies "beat" together (one frequency minus the second frequency = heterodyne).

Hertz: See Hz.

HF: High Frequency, a range of frequencies from 3 to 30 MHz.

Hz (Hertz): A measure of frequency: one cycle per second

Inductor: A coil onto which voltage is imposed by another coil.

Impedance: The apparent opposition in an electrical circuit to the flow of an alternating current

Ionosphere: Electricity conducting layers in the earth's upper atmosphere

KHz: 1000 Hertz

LCD: Liquid Crystal Display

LPA: Linear Power Amplifier

LSB: Lower Sideband

LED: Light-Emitting Diode, a semiconductor that lights up; used in digital displays.

Memory: A computer memory address to which channel information may be assigned

MHz: 1 million Hertz

MF: Medium Frequency, a band of frequencies in the 2 MHz range used for short range communications

Microprocessor: A computer processor contained on a chip.

Modulation: The process of varying the amplitude, frequency or phase of a carrier or signal

Oscillator: A device that produces alternating current

Oscilloscope: A display of frequency on a cathode ray tube.

PCB: Printed Circuit Board

Phase-shift: Removing an unwanted frequency (or sideband) by imposing a mirror-image frequency so the two cancel each other.

PTT: Push to Talk, a common radio function

PEP: Peak Envelope Power; commonly a power output rating

Propagation: The characteristics of different radio frequency transmissions, generally in regard to usable distance in relation to frequency and time of day

RF: Radio Frequency; any frequency higher than a person can hear

Resonate: The frequency that a circuit is tuned to

Radiate: The movement of energy away from a place, as in the radiation of an antenna

SSB: Single Side Band; a high efficiency type of radio transmission generally used for long distance communications where energy is not radiated until modulation is present

SQL: Squelch

Simplex: A method of frequency use in which stations transit and receive on the same frequency

SITOR: A commercial system of radio teletype for ship to shore, ship to ship and between ships and any telex subscriber; "ship international transmitting over radio"

Skip: The bounce of the radio signal off the ionosphere

Skywave: A radio signal which is projected into the ionosphere and bounces one or more times before returning to earth

Synthesize: The device that produces and controls frequencies through synthetic results

SNS: Exclusive to SGC; spectral noise subtraction; works with DSP in signal processing to improve incoming signals

TELEX: A commercial service involving teletypewriters connected through automatic exchange; "teleprinter + exchange"

Transceiver: A term applied to equipment that both transmits and receives

USB: Upper Sideband

UTC: Coordinated Universal Time; same as GMT

VCO: Voltage Controlled Oscillator

VHF: Very High Frequency; commonly refers to a short range type of radio whose signal is transmitted on a line of sight from antenna to antenna

VSWR: Voltage Standing Wave Ratio; a measurement of the efficiency of an antenna system; it measures the energy which is projected out and reflected back to the antenna

Voltage: A measurement of electrical pressure of the current times resistance

VDC: Voltage Direct Current

Wavelength: Distance between two successive radio waves

Work: To be in radio contact or communication with another station

XMT: Transmit

XFMR: Transformer