Technician License Study Guide - Glossary Flashcards
alternating current. Alternating current is the name for current that reverses direction on a regular basis. The power outlets in your home provide alternating current.
AC
Automatic Packet Reporting System. Digital communications system used by amateur radio operators. While it is normally used for tracking the location of mobile stations, it can be used for other purposes as well. For more information, go to http://www.aprs.org.
APRS
Amateur Radio Emergency Service consists of licensed amateurs who have voluntarily registered their qualifications and equipment with their local ARES leadership for communications duty in the public service when disaster strikes. For more information,
go to http://www.arrl.org/ares.
ARES
amplitude modulation. The type of modulation that varies the amplitude of a radio signal in accordance with the amplitude of a modulating signal. For more information, go to http://www.pa2old.nl/files/am_fundamentals.pdf.
AM
plan showing how frequencies within a particular amateur radio band are assigned to
different modes so that operators may avoid interfering with one another.
band plan
directional antenna.
beam antenna
Continuous Tone Coded Squelch System. A system that uses sub-audible tones, transmitted along with the audio portion of a transmission to control whether or not a repeater will re-transmit a signal. It is known by a number of different trade names, including Private Line® (PL) by Motorola. In
practice, it’s used to prevent nearby transmitters from inadvertently turning on repeaters.
CTCSS
continuous wave. This is the operating mode amateur radio operators use when sending Morse
Code.
CW
direct current. Direct current is the name for current that never reverses direction.
Digital Mobile Radio: radio standard for time-division multiplexing two digital voice signals on a 12.5
KHz repeater channel.
DC
Digital Mobile Radio
DMR
dual-tone, multi-frequency. DTMF is a type of signaling used to send data over voice channels. Its most common use in amateur radio is to allow users of handheld transceivers to send commands to repeater systems. It is called DTMF because every time a user presses a keypad button a unique tone
consisting of two frequencies is transmitted. For more information, see
http://www.genave.com/dtmf.htm.
DTMF
system that links amateur radio stations and computing devices using Voice over IP
(VOIP). electromotive force (EMF): force that propels electric charge through a conductor or circuit; expressed 121in volts (V).
EchoLink
Federal Communications Commission. This is the government body which sets the rules for
amateur radio in the U.S.
FCC
wire or cable that carries signals from a transmitter to an antenna or from an antenna to a
receiver.
feed line
frequency modulation. The type of modulation normally used when operating on VHF and UHF
repeaters.
FM