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m
|
Mill- on-thousandth or 10-3.
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M
|
Mega-, one million or 106 .
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MAC (A-, B-, C- or D-)
|
Multiplexed Analog Components. An enhanced color TV transmission
system developed especially for satellite use. Differences
between the various types of MAC have to do with the various
types of sound and data channels used.
|
|
Magnetic Variation
|
The difference between true north and the north indication
of a compass.
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Marginal
|
Describes a system operating with nil, or inadequate, signal
margin.
|
|
Master Antenna TV (MATV)
|
Broadcast receiving stations that use one or more high-quality
centrally located UHF and/or VHF antennas which relay their
signals to many televisions in a local apartment/condo or
group-housing complex.
|
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Match
|
The condition that exists when 100 percent of available
power is transmitted from one device to another without
any losses due to reflections.
|
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Matching Transformer
|
A device used to match impedance between devices. A matching
transformer is used, for example, when connecting a 75 ohm
coax to a television 300 ohm input terminal.
|
|
MATV
|
Master Antenna Television - private cable.
|
|
MBTA
|
Multiple Beam Tours Antena (Comsat design)
|
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Medium Power Satellite
|
Satellite with transponder RF power in the region of 3OW
to 1OOW.
|
|
Medium Power Satellite
|
Satellite with transponder RF power in the region of 30
to 60 watts.
|
|
MegaHertz (MHz)
|
One millions cycles per second.
|
|
Meridians
|
Lines circling from pole to pole which cross each of the
360 degrees which comprise the Earth's equator.
|
|
Micro
|
A numerical prefix denoting one-millionth (106
).
|
|
Microprocessor
|
The central processing unit of a computer or control system,
either on a single integrated (IC) circuit chip or on several
Ics.
|
|
Microwave
|
The frequency range from approximately 1 to 30 GHz and
above.
|
|
Microwave Interference
|
Interference which occurs when an earth station aimed at
a distant satellite picks up a second, often stronger signal,
from a local telephone terrestrial microwave relay transmitter.
Microwave interference can also be produced by nearby radar
transmitters as well as the sun itself. Relocating the antenna
by only several feet will often completely eliminate the
microwave interference.
|
|
Mil
|
A unit used in measuring diameter of a wire or thickness
of insulation over a conductor. One one-thousandth of an
inch (.001").
|
|
Mixer
|
A device used to combine signals together.
|
|
MMDS
|
Microwave Multipoint Distribution Service also known as
wireless cable.
|
|
Modem
|
Modulator/demodulator, Usually applied to a device for
converting digital data to audio tones (and vice versa)
for transmission via an analog channel.
|
|
Modulation
|
A process in which a message is added or encoded onto a
carrier wave. Among other methods, this can be accomplished
by frequency or amplitude modulation, known as AM or FM,
respectively.
|
|
Modulation Index
|
The ratio of peak deviation to highest modulating frequency,
in an FM system.
|
|
Modulator,AM
|
Consumer satellite receivers are equipped with a VHF or
UHF demodulator to supply a standard AM TV channel to home
TV receiver
|
|
Modulus of Elasticity
|
The ratio of stress to strain in an elastic material.
|
|
Monochrome
|
A black and white television picture.
|
|
Monomer
|
The basic chemical unit used in building a polymer.
|
|
Monopulse
|
Hardware-based automatic antenna tracking system.
|
|
Mount
|
The structure that supports an earth station antenna. Polar
and az-el mounts are the most commonly variety.
|
|
MSO
|
Multiple cable systems operator - a cable operator owning
more than one cable network. MSO examples in India are Siticable,
In Cablenet, Hathaway, Asianet.
|
|
Multiplexing
|
Techniques that allow a number of simultaneous transmissions
over a single circuit.
|
|
Multiburst
|
A video test waveform included ins ITS.
|
|
Multiple Analog Component (MAC) Transmissions
|
An innovative television transmission method which separate
the data, chrominance and luminance components and compresses
them for sequential relay over one television scan line.
There are a number of system in use and under development
including A-MAC, C-MAC, D-MAC, D2-MAC, E-MAC and F-MAC.
|
|
Multiplexing
|
The simultaneous transmission of two or more signals over
a single communication channel. The interleaving of the
luminance and chrominance signals is one form of multiplexing,
known as frequency multiplexing. MAC transmissions make
use of time division multiplexing
|
|
Multipoint
|
A single communications line or circuit interconnecting
several stations. Use of this type of line usually requires
some kind of polling mechanism to address each terminal
with a unique address code.
|
| Must carry |
Legal requirement in the US that
cable operators carry local broadcast signals. Cable systems
with 12 or fewer channels must carry at least three broadcast
signals; systems with 12 or more channels must carry up to
one-third of their capacity; systems with 300 or fewer subscribers
are exempt. The 1992 Cable Act requires broadcast station
to waive must-carry rights if it chooses to negotiate retransmission
compensation. |
|
Mutual Capacitance
|
Capacitance between two conductors when all the other conductors
including ground are connected together and then regarded
as an ignored ground.
|
|
Mux
|
Multiplexer.
|
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