Technician License Study Guide - Glossary

Question 1

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.

Answer 1

AC

Question 2

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.

Answer 2

APRS

Question 3

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.

Answer 3

ARES

Question 4

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.

Answer 4

AM

Question 5

plan showing how frequencies within a particular amateur radio band are assigned to
different modes so that operators may avoid interfering with one another.

Answer 5

band plan

Question 6

directional antenna.

Answer 6

beam antenna

Question 7

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.

Answer 7

CTCSS

Question 8

continuous wave. This is the operating mode amateur radio operators use when sending Morse
Code.

Answer 8

CW

Question 9

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.

Answer 9

DC

Question 10

Digital Mobile Radio

Answer 10

DMR

Question 11

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.

Answer 11

DTMF

Question 12

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).

Answer 12

EchoLink

Question 13

Federal Communications Commission. This is the government body which sets the rules for
amateur radio in the U.S.

Answer 13

FCC

Question 14

wire or cable that carries signals from a transmitter to an antenna or from an antenna to a
receiver.

Answer 14

feed line

Question 15

frequency modulation. The type of modulation normally used when operating on VHF and UHF
repeaters.

Answer 15

FM

Question 16

data transmission protocols designed for very weak signal communication.

Answer 16

FT8

Question 17

high frequency. The range of frequencies between 3 MHz and 30 MHz.

Answer 17

HF

Question 18

handy-talky or handheld transceiver. “Handy Talky” is a Motorola trademark.

Answer 18

HT

Question 19

International Telecommunications Union. This is the international body which governs amateur
radio worldwide.

Answer 19

ITU

Question 20

lower sideband. See SSB.

Answer 20

LSB

Question 21

multi-frequency shift keying. A type of modulation used to send digital information over a
radio channel.

Answer 21

MFSK

Question 22

Private Line. See CTCSS.

Answer 22

PL

Question 23

male connector often used to connect feedlines to a radio.
polarization: orientation of the electric field a radio wave.

Answer 23

PL-259

Question 24

phase shift keying. A method for sending digital information over a radio channel. A popular amateur radio “digital mode” is PSK31, which uses PSK modulation and occupies only 31 Hz of
bandwidth.

Answer 24

PSK

Question 25

push-to-talk

Answer 25

PTT

Question 26

Radio Amateur Civil Emergency Service. RACES is an amateur radio emergency communications service created by the Federal Emergency Management Agency (FEMA) and the FCC. RACES volunteers serve their respective jurisdictions pursuant to guidelines and mandates established by local emergency management officials. See http://www.usraces.org/ for more information.

Answer 26

RACES

Question 27

receiver incremental tuning. A control which allows a user to set the receive frequency of a transceiver either slightly higher or slightly lower than the transmit frequency.

Answer 27

RIT

Question 28

radio frequency

Answer 28

RF

Question 29

single sideband. When a carrier is amplitude modulated, both upper and lower sidebands are produced. This results in a signal that is 6 kHz wide. Since both sidebands carry the same information, and the carrier carries no information, someone figured out that if they could filter out the carrier and one of the sidebands, and put all the power into a single sideband, the efficiency of voice SSB:

Answer 29

SSB

Question 30

standing-wave ratio. The SWR of an antenna system is a measure of how closely the impedances of the antenna and feedline match the output impedance of the transmitter.

Answer 30

SWR

Question 31

virtual channel that connects amateur radio operators through a repeater or over the internet.

Answer 31

talk group

Question 32

very high frequency. The range of frequencies between 30 MHz and 300 MHz.

Answer 32

VHF

Question 33

Universal Licensing System. The FCC’s Universal Licensing system contains information on all FCC licensees, including amateur radio operators. For more information, go to http://www.fcc.gov/uls.

Answer 33

ULS

Question 34

ultra high frequency. The range of frequencies between 300 MHz and 3000 MHz. 41

Answer 34

UHF

Question 35

upper sideband. See SSB.

Answer 35

USB

Question 36

variable frequency oscillator. VFOs are used to control the receiving and transmitting frequencies of amateur radio equipment.

Answer 36

VFO

Question 37

amateur radio software developed by Joe Taylor, K1JT, that supports weak-signal and low-power digital communication modes, such as - JT65, JT4, JT9, and QRA64 (EME); - FSK441and JTMS (meteor scatter); - JT6M and ISCAT (ionospheric scatter), and - FT8 and FT4.

Answer 37

WSJT, WSJT-X