TM 11-5805-384-30
GLOSSARY
AC. An abbreviation for alternating current.
ALTERNATING CURRENT. Electric current that continually changes in magnitude and direction.
AMPLIFICATION. The process of increasing the voltage, current, or power of a signal.
AMPLIFIER. A device consisting of one or more components used to increase a signal.
BANDWIDTH. A range of frequencies which fall within set limits. These limits are established by the number of cycles per second of
BUSY SIGNAL. A series of short tones sent to the telephone set by the switching facility to indicate when the telephone set being
called is busy.
CONFERENCE. A telephone conversation between three or more people.
CURRENT. The movement of electrons through a conductor.
DC. An abbreviation for direct current.
DIAL TONE. A continuous tone sent to the telephone set by the switching facility to indicate that the switching facility is ready to
accept the telephone number of a distant phone.
DIRECT CURRENT. Electric current that flows in only one direction and remains constant in
EXTENSION TELEPHONE. A telephone which is connected directly to another telephone.
FREQUENCY. The number of cycles of a signal in a given time, usually per second.
GROUND. The zero reference point in electronic equipment regarding voltage.
HERTZ. A term meaning cycle per second, abbreviated Hz.
IMPEDANCE. The opposition of a circuit to the flow of current. This resistance is measured in ohms.
Glossary 1