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tee junction • telephone amplifier 675
tee junction 1. A tee-shaped splice between two
wires. 2. A tee-shaped fixture for splicing one coaxial
line perpendicularly to another. 3. A tee-shaped
section for joining one waveguide perpendicularly
to another. Also called WAVE GUIDE TEE.
tee junction
tee network A three-terminal network resembling
a tee.
tee pad A three-resistor pad in which two series resistors
and a shunt resistor are arranged to form
a tee.
tee switch A combination of three switches arranged
to form a tee; two switches are in series
with a shunt switch in between. If the series
switches are open and the shunt switch is closed,
isolation is greatly improved, compared to a single
series switch.
Teflon FEP A plastic insulating material. Dielectric
constant, 2.1. Dielectric strength, 2800 V/mil.
Teflon TFE A plastic insulating material. Dielectric
constant, 2.2. Dielectric strength, 600 V/mil.
tel 1. Abbreviation of TELEPHONE. 2. Abbreviation
of TELEGRAPH. 3. Abbreviation of TELE-
GRAM.
telautograph A device that transmits and receives
handwriting, drawings, and similar material. At
the receiver, a pen follows the movements of a
similar pen at the transmitter.
teleammeter A TELEMETER for measuring current
generated at a remote point.
telecamera See TELEVISION CAMERA.
telecast A television program for general reception.
The term a contraction of television broadcast.
telechir A remotely controlled, autonomous robot.
See TELEOPERATION and TELEPRESENCE.
telecommunication Communication, usually between
widely separated points, by electrical or
electronic means.
telecontrol See REMOTE CONTROL and TELEOP-
ERATION.
telefacsimile See FACSIMILE.
telegram Abbreviation, tel. A (usually printed-out)
message transmitted and received via telegraph
or teletypewriter. Compare CABLEGRAM and RA-
DIOGRAM.
telegraph Abbreviation, tel. An instrument for
transmitting and receiving messages by means of
telegraphy. In its simplest form, it consists of a
key and a sounder powered by a battery. Also see
PRINTING TELEGRAPH, 1, 2.
telegraph channel 1. The frequency band assigned
to a particular telegraph station. 2. The
frequency band occupied by a telegraph signal.
telegraph code Broadly, Morse code. Wire telegraphy
often uses a special version, such as the
American Morse code.
telegraph key See KEY, 1.
telegraph sounder See SOUNDER.
telegraph system A complete, integrated, coordinated
arrangement of equipment for communication
by means of telegraphy. Included are
telegraph keys or keyers, sounders or printers,
relays, switchboards, wire lines and cables, and
power supplies.
telegraphy
The branch of electrical communications
that deals with the transmission and reception
of messages by means of prearranged
codes—especially over wires. Also see MORSE, 1,
2, 3; MORSE CODE; and WIRE TELEGRAPHY.
telemeter
1. An indicating instrument that measures
the value of a quantity generated at a distant
point or measures and transmits the value.
2. The action afforded by the device in 1.
telemetering See TELEMETRY.
telemeter receiver See TELEMETRIC RECEIVER.
telemeter transmitter See TELEMETRIC TRANS-
MITTER.
telemetric receiver A system that selects, amplifies,
and demodulates or rectifies a radio signal,
and actuates indicating instruments, recorders,
or data processors.
telemetric transmitter A specialized transmitter
that generates radio-frequency (RF) power, adds
to it signals delivered by data transducers, and
delivers the modulated power to an antenna for
transmission to a distant telemetric receiver.
telemetry
The transmission of data signals over a
distance, either by radio or wire, and the reception
and application of the signals to indicating
instruments, recorders, etc.
teleoperation The remote control of autonomous
robots. A human operator can control the speed,
direction, and other movements of a robot from
some distance away. See also TELEPRESENCE.
telephone
Abbreviation, tel. An instrument for
transmitting and receiving messages by means of
telephony. In its simplest form, it consists of a
microphone, earphone, switching and ringing devices,
wire line or cable, and power supply. Also
see HANDSET.
telephone accessories Devices (such as answering
machines, speaker phones, facsimile machines,
etc.) used in conjunction with a telephone set.
telephone amplifier A small audio amplifier, usually
with a self-contained loudspeaker, for increasing
the sound volume of a telephone output.
Some amplifiers of this kind are connected to the