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
SGC Inc., Tel:
425-746-6310 Email: sgc1@sgcworld.comSGC reserves the right to change specifications, release dates and price without notice.
