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Signal Mismatch–A condition in which an antenna
system delivers signals whose strengths and general
quality vary. This usually is the result of incorrectly
installed
signal-distribution
Interaction, Signal.)
Sound Carrier (TV)–The part of a TV signal that
contains the audio (sound) information. (The picture
information is contained in the picture carrier.)
Standard Household Current (117V/AC)–The type of
electrical power that is delivered to and operates
appliances, lighting, electrical outlets and other
electrical devices in a home. It is called alternating
current (AC), and its normal value is 117 volts.
Standout (Standoff)–A metallic device with wood-
screw threads or a clamp on one end and a circular
loop (eye) with slotted insulating material on the
other. It is used to secure and hold 300 ohm twinlead
or other unshielded transmission line away from
metal gutters, walls and other surfaces that can
change the line's signal-handling characteristics. The
standout is screwed into a wall or other part of the
house or is clamped onto the antenna mast. The
transmission line then is inserted in the slot of the
insulating material in the eye.
Star Bit–A steel, punch-like device that is hit with a
hammer to "drill" holes through masonry (brick,
cement block, etc.)
Switchable Trap–A small device that is used with a
preamp to eliminate (trap out) an unwanted bank of
signals. It is called "switchable" because it can be
switched on or off (although this is difficult because
the trap is mounted with the preamp up near the
antenna). A switchable trap usually is used to
eliminate the FM band
Tandem System–A preamp and a distributive amplifier
that are designed to be used together.
Tensile Strength–The ability of a material or struc-
ture (such as an antenna mast) to withstand large
bending forces without distorting or breaking apart.
Tensile strength is an important factor to consider
when selecting a mast and planning an installation.
Terminal Lug–A two-pronged connective device that
is used to secure a wire to an electrical terminal. One
end of the device is crimped onto the bared wire. The
two flat prongs then are slipped around the terminal
screw, and the screw head is tightened down against
the prongs, securing the electrical connections.
Transmission Line–A two (or more) conductor wire
that is used to carry current or signals from one point
to another. Twinlead and coaxial cable are the most
common types of transmission line used to carry TV
signals from the antenna(s) to the receiver.
components.
(See
Tunable Trap–A small device that can be tuned
(adjusted) to eliminate any one of the number of
frequencies within a band. Tunable traps are
frequently used with preamps, to eliminate a
particularly troublesome signal.
Twinlead–A type of unshielded ribbon-like transmis-
sion line that consists of two insulated conductors
(wire) separated by a thin, flat expanse of insulating
material. TV twinlead has a characteristic impedance
of 300 ohms, and therefore is called 300 ohm twin-
lead.
UHF (TV)–UHF means ultra-high frequency. When
used in relation to TV, UHF refers to channels
14 through 69, whose frequencies are located in the
UHF band. Modern TV receivers have two separate
tuners, one for VHF (channels 2 through 13), and one
for UHF (channels 14 through 69). Although the UHF
tuners of some television receivers can also be tuned
to channels 70 through 83, there are no TV signals on
these channels because the FCC has reassigned their
frequencies to other uses.
UHF/VHF (TV)–An indication that a TV receiver or
antenna is capable of receiving both the UHF and the
VHF channels.
VHF (TV)–VHF means very-high frequency. When
used in relation TV, VHF refers to channels 2 through
13, whose frequencies falls within the VHF band. The
TV VHF band is divided into two subbands: (1) the
low band, which includes channels 2 through 6 and
a frequency range of 54 MHz-88 MHz, and (2) the high
band, which includes channels 7 through 13 and a
frequency range of 174 MHz-216 MHz. A portion of
the frequency band between channels 6 and 7 is used
for FM radio stations.
VHF/FM Broadband Antenna (TV)–A TV antenna
that is capable of receiving the complete TV
VHF band (channels 2-13) and also the FM band
(88 MHz-108 MHz).
VHF/UHF/FM (TV)–An indication that a TV receiver
or antenna is capable of receiving all VHF channels
(2-13), all UHF channels (14-69), and FM band
(88 MHz-108 MHz).
Weather Boot–A rubber-like covering that is used to
protect outdoor electrical connections from the
weather (rain, ice, etc.).
G
LOSSARY
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