View all frequently asked questions
In Raleigh, Most network broadcast towers are broadcasting in UHF carriers excpt for ABC 11 is still in VHF. A High Gain UHF Antenna is perferable for the triangle area.
NO, Antennas are typically built in one plane allowing signal to enter from the front and back with high gain on front and back and conciderable signal drop off on the side lobes.
Using 2 high gain antennas perpendicular to each other gets a omni directional setup for those tricky installs
There are Omni Directional antennas, however, they are not high gain. They are typlically used on campers that are not stationary.
All roof surfaces block RF (Radio Frequencies), some more than others. Size of the antenna will matter.
If LOS (Line of sight) to towers are not a problem from the house than the location of the antenna in the attic will depend on whether or not there are vents, dormer windows, and openings for the RF to get in. Otherwise,, you stand a good chance of receiving stable while keeping it out of sight.
ANTENNA AMPLIFERS WILL NOT INCREASE SIGNAL FROM THE AIR TO THE ANTENNA.
Use of an amplifier will only help put back the signal lost thru passive devices and cable.
Pixilation occures when signal level is not high enough for the TV to build the picture. Signal loss accures two ways. 1)Insufficient signal picked up from your antenna due to terrain or elevation line of sight to tower and 2) through passive device loss and cable loss.
Remember: ONLY size of the antenna and elevation/height will directly impact signal gain. NOT preamps
1st- Lets talk about antennas! I say antennas are like an sail is to a ship, The higher the sail is, the better and the larger the sail is, the better it is equipt to gather the air to work.
Trouble is, ...everyone wants there antenna hidden. Sometimes you may get away with an attic install.
2nd- RF or Radio Frequencies from towers are actually(photons traveling in straight lines) is like shinning a flshlight in a dark room. If there are things in the way, there will be BLACK or BLACK OUT areas behind it. Same can happen with RF from television towers. Also, If there are highly reflective things near by such as building, It will relect just like light. It maybe possible to get signal off of the neighbors roof or building reflecting back to you from a different angle.
You can then look at purchasing a HIGH GAIN antenna for your whole home.
We offer a wide variety of antennas on our store.
No- Only network channels are available free off the air. However, There are more networks than thee use to be.
7 years ago there were only 9 channels and now there are more than 26 free channels.
DIRECTV satellites are located South West over Texas and Mexico looking from NC. Generally 220-258 deg.SW with a compass and 38-45 elevation. Use this for surveying.
FYI-For KU FTA, Dishnet, and all Hughes feeds also located over Texas and Mexico at 198-270 deg SW and between 26- 50deg elevation.
With the increasing popularity of home satellite television, conflicts are bound to arise between prospective dish users, regulations, and restrictive covenants that prohibit satellite dishes. In anticipation of these conflicts, and to facilitate competition between cable television providers and satellite television providers, Congress included a provision in the 1996 Telecommunications Act (Act) that directed the Federal Communications Commission (FCC) to promulgate rules that would regulate the use of direct-to-home satellite dishes. Telecommunications Act of 1996, § 207, PL 104-104, 110 Stat 56, February 8, 1996.
The FCC responded by enacting 47 CFR § 1.4000. Under these new rules, private restrictions against satellite receivers that are less than one meter in diameter are presumptively unreasonable and prohibited, unless the restriction has either a clearly defined and valid safety objective or is necessary to preserve a recognized historic district. Even if the regulation serves one of these two purposes, the restriction may be only as burdensome as is necessary to achieve the allowed purpose. The restriction is prohibited only to the extent that it impairs a person's use of a particular type of receiver. A restriction is said to impair installation, maintenance or use of an antenna if it delays or prevents these actions, unreasonably increases the cost of these actions, or precludes reception of an acceptable quality signal. See 47 CFR § 1.4000. The purpose of this article is to provide a brief look at the law prior to the Act, and then to analyze the impact and possible future effects of the 1996 FCC rule.
ADEC GLOSSARY OF TERMS
Applicable to Satellite, Telecommunications and Computer
August 27, 2000
The Glossary Index identifies dates of new entries since
Words and terms in bold are defined in this Glossary.
ACTS (ADVANCED COMMUNICATIONS TECHNOLOGY SATELLITE): The NASA
experimental satellite project which demonstrated the use of the
Ka Band (30/20 GHz) services; on-board processing with multiple
beams, electronic hopping antenna beams, and dynamic adjuctment
of power to cope with rain attenuation. The experimental network
supported low to medium rate mobile services to high data rate
HDTV fixed services. (Pelton, 1995)
ALGORITHM: A procedure or formula for solving a mathematical
problem in a finite number of steps. Extremely complex algorithms
or sets of algorithms are used to simplify, modify or predict
data in the digital manipulation of information. Often,
algorithms which are developed for digital applications are
proprietary and are an important aspect of defining significant
differences among the various digital compression and codec
AM (AMPLITUDE MODULATION): Modulation which is accomplished by
varying the amplitude (height of the carrier wave) of the carrier
signal in accordance with the information to be transmitted.
(Inglis & Luther, 1996)
ANALOG: Representing something in the real world. Analog is often
used in comparison with digital, for example comparing analog and
digital computers or analog or digital electrical signals. Analog
computers actually measure, analyze and compute using real
physical measures and numbers. Analog electrical signals (such as
the radio frequencies used to transmit telecommunications
information) are directly generated by physical stimuli in the
form of light or sound waves.
APERTURE: In image scanning, the size of the sensitive spot that
moves over the image. In an antenna, an imaginary cylinder in
space surrounding the radiating elements. (Inglis & Luther,
APOGEE: The point in an elliptical satellite orbit which is
farthest from the center of the earth (the opposite of perigee).
ARTIFACT: Any anomaly, distortion or unnatural component in an
image -- usually associated with digital video transmission. (See
ASCII (AMERICAN STANDARD CODE FOR INFORMATION INTERCHANGE): A
standardized format for computer system text coding.
ASPECT RATIO: The ratio of the width to the height of an image.
For example, analog television uses a 4:3 (1.33) aspect ratio,
while HDTV has an aspect ratio of 16:9 (1.78). (Inglis & Luther,
ATM (ASYNCHRONOUS TRANSFER MODE): A high-speed (155 and 622
Mb/s), fast-packet switching technique employing short, fixed
length cells that are statistically multiplexed over virtual
connections. Each cell consists of a 5-octet header and a 48-
octet payload of user information (data, voice, or video).
ATSC (ADVANCED TELEVISION SYSTEMS COMMITTEE): An international
organization of approximately 200 members that is establishing
voluntary technical standards for advanced television systems.
ATSC Digital TV Standards include digital HDTV (High Definition
Television), SDTV (Standard Definition Television), data
broadcasting, multichannel surround-sound audio, and Satellite
(ATSC Home Page, http://www.atsc.org/, Oct 06, 1999)
ATTENUATION: The loss of power of electomagnetic signals between
transmission and reception points. (Pelton, 1995)
AZIMUTH: The definition from Webster s New Collegiate Dictionary
states, "an arc of the horizon measured between a fixed point
such as true north and the vertical circle passing through the
center of an object." Azimuth is an important consideration in
locating a satellite for transmission or reception of RF signals.
The azimuth expressed in degrees of a circle will be the
horizontal angle of rotation that the ground antenna must be
rotated though to point at the specific satellite. Azimuth angles
for any satellite may be calculated given the latitude and
longitude of the ground station and the location of the satellite
in geosynchronous orbit relative to true north.
BACKHAUL: A process where a television signal is transmitted from
a remote site to a central site where the backhaul signal is
integrated into a program which is being broadcast from the
BANDWIDTH: A measure of radio frequency (RF) use or capacity. A
terrestrial broadcast television channel, for example occupies a
RF bandwidth of 6 MHz or six million cycles per second while a
telephone voice transmission requires a RF bandwidth of only 3
KHz or 3,000 cycles per second.
BASEBAND: The bandwidth of the modulating (message) signal.
A transmission medium through which digital signals are sent
without frequency shifting. In general, only one communication
channel is available at any given time. Ethernet is an example
of a baseband network. (Howe, 1999)
BAUD: A description of the rate of data transmission usually
expressed in bit rate measurements of thousand bits per second
(Kb/s). A 14.4 Baud modem for example will accommodate a bit rate
of 14,400 bits per second.
BIG LEO: (See LE0: LOW EARTH ORBIT)
B-ISDN (BROADBAND ISDN): An ISDN (Integrated Services Digital
Network) offering broadband capabilities. B-ISDN is a CCITTproposed
service that may (a) include interfaces operating at
data rates from 150 to 600 Mb/s, (b) use ATM (Asynchronous
Transfer Mode) to carry all services over a single, integrated,
high-speed packet-switched network, (c)have LAN interconnection
capability, (d) provide access to a remote, shared disk server,
(e) provide voice/video/data teleconferencing, (f) provide
transport for programming services such as cable TV, (g) provide
single-user controlled access to remote video sources, (h) handle
voice/video telephone calls and (I)access shop-at-home and other
information services. (GSA, 1996)
BIT: (Abbreviation for binary digit ) The smallest increment of
digital information. Often referred to as a 1 or 0 in the binary
system. Also referred to as an 'on' or 'off' when referring to
the mechanical operation of bits in the computer.
BIT RATE: The amount of data being transported, measured relative
to quantity over time in bits per second (thousand bits per
second or Kb/s, million bits per second or Mb/s, billion bits per
second or Gb/s and trillion bits per second or Tb/s).
Summary of bitrate notations:
Bit: 10p0 (1 bit)
Kilobit: 10p3 (1,000 bits)
Megabit: 10p6 (1,000,000 bits)
Gigibit: 10p9 (1,000,000,000 bits)
Terabit: 10p12 (1,000,000,000,000 bits)
Petabit: 10p15 (1,000,000,000,000,000 bits)
Exabit: 10p18 (1,000,000,000,000,000,000 bits)
Zettabit: 10p21 (1,000,000,000,000,000,000,000 bits)
Yottabit: 10p24 (1,000,000,000,000,000,000,000,000 bits)
A 40 Exabit file would contain all of the words ever spoken by
BIT STREAM: (see DIGITAL BIT STREAM)
BROADBAND: (See WIDEBAND)
BSS (BROADCAST SATELLITE SERVICE): The segment of Ku-band
satellite service established by the FCC which is provided by
high power satellites (or clusters of satellites) which must be
separated in orbit by 9 degrees. The frequencies of RF signals
transmitted to and received from the BSS satellites are higher
than those permitted for FSS satellites. The BSS transmission
frequency from high-power satellites to satellite receivers has
been established by the FCC between 12.2 - 12.7 GHz.
BYTE: (Abbreviation for binary term ) The simplest combination
of bits producing recognizable information such as a number or a
word. For example, the number 50 is represented by a byte made up
of the eight bits 0,0,1,1,0,0,1 and 0.
CACHE: A small fast memory which holds recently accessed data,
designed to speed up subsequent access to the same data. Most
often applied to processor-memory access but also used for a
local copy of data accessible over a network, etc. (Howe, 1999)
C-BAND: A portion of the Radio Frequency (RF) spectrum located
between 4 GHz and 8 GHz, a part of which is dedicated to
satellite communications. Satellite downlink frequencies are
located between 3.7 GHz and 4.2 GHz and uplink frequencies are
located between 5.925 GHz and 6.425 GHz.
CDMA (CODE DIVISION MULTIPLE ACCESS): See (MULTIPLE ACCESS)
CHROMINANCE: In color video systems, the signal component(s) that
describe Color Difference information. (Inglis & Luther, 1996)
CLARKE ORBIT: (See GEO)
CLIFF EFFECT: A characteristic of the digital transmission of RF
signals where there is a radical change in reception quality
which results from a small change in reception power. By
comparison, when an analog RF signal approaches the fringes of
acceptable reception power, the television picture begins to
experience gradual degradation with increasing sparkles or snow.
As a digital RF signal reaches the fringes of acceptable
reception power, there is no discernible degradation of picture
quality until the level of reduced power reaches a threshold. At
that point, picture quality changes from perfect to no picture.
CLIPPER CHIP: An asymmetric encryption chip proposed for use by
the United States government so that the pervasive encryption of
communication channels shall not protect both the law-abiding and
law-breakers. Designated MYK-78, a secret key is created at the
time of manufacture and placed in escrow. With court approval,
government agencies can obtain this key and employ it to decipher
encrypted messages obtained through wiretaps. (Carne, 1995)
COLOR DIFFERENCE: In a color video system, signals that represent
the difference between specified colors and the luminance
component. They have the property that they go to zero for
monochrome images. (Inglis & Luther, 1996)
COMMON CARRIER: An entity which provides communication
transmission facilities for use by other entities or which
carries other entity's communications signals. Examples of common
carriers include the telephone or telegraph companies and the
companies which own communications satellites. Common carriers
are subject to tariff regulation and must file rates for specific
services with appropriate regulatory agencies such as the FCC or
state regulatory agencies. As a rule, common carriers are not
permitted to control content.
CONUS (CONTIGUOUS UNITED STATES): A term used to describe
satellite coverage limited to the continental United States
excluding Alaska and Hawaii.
DAMA (DEMAND-ASSIGNED MULTIPLE ACCESS): A process whereby
satellite transponder channels are assigned for telephony
transmission on the basis of immediate traffic demands.
DARPA (DEFENSE ADVANCED RESEARCH PROJECTS AGENCY): An agency of
the USDoD (United States Department of Defense) responsible for
the development of new technology for use by the military. DARPA,
originally ARPA, was established in 1958. The agency is
independent from other more conventional military R&D operations
and focusses on short (two to four-year) projects run by small,
purpose-built teams. ARPA was responsible for funding
development of ARPANET (which grew into the Internet), as well as
the Berkeley version of Unix and TCP/IP. (Howe, 1999)
dB (DECIBEL): An analog unit of measure of signal strength,
volume, or signal loss due to resistance as expressed in
logarithmic form. (Satellite Industry News, Jan, 1999)
DCII (DIGICIPHER II): An MPEG II digital standard developed by
General Instruments Corporation which uses the MPEG II video
encoding standards and the ATSC (Advanced Television Systems
Committee) Dolby AC-3 digital audio standard. This standard has
been adopted for standard and high definition television (SDTV &
HDTV) transmission in North America, South Korea and Taiwan (see
DIGITAL: The conversion of information into a binary format (1's
and 0's or on's and off's), the smallest or simplest unit of
information being a bit. These bits of information may be
transmitted using radio frequency techniques such as terrestrial
broadcasting, satellite and microwave transmission or over
coaxial or fiber optic cable and copper wire. Digital information
may be manipulated at extremely high speeds.
DIGITAL ARTIFACTS: Errors in a digital transmission of data which
result from digital compression applications which remove
information from a data inventory in an amount sufficient to
cause noticeable anomalies.
DIGITAL BIT STREAM: A continuously changing flow of digital
information which is being transported over some transmission
medium such as cable or on a satellite microwave frequency.
DIGITAL COMPRESSION: A process by which complex sets of
algorithms are employed to rearrange, reassemble and eliminate
digital information from a data inventory in such a way that the
amount of data (bits) to be stored or transported is reduced
without a resulting loss of apparent resolution.
DSL (DIGITAL SUBSCRIBER LINE): In ISDN (Integrated Services
Digital Networks), equipment that provides full-duplex service on
a single twisted metallic pair at a rate sufficient to support
ISDN basic access and additional framing, timing recovery, and
operational functions. The physical termination of the DSL at
the network end is the line termination; the physical termination
at the customer end is the network termination. (GSA, 1996)
DS-LEVEL: DIGITAL SIGNAL LEVEL:
DS-0: 64 Kb/s.
DS-0A: A DS-0 signal containing data from a single
subrate station. The bytes are repeated as necessary to
match the sender s speed to the speed of the DS-0 line.
DS-0B: A DS-0 signal containing data from several subrate
stations. The octets contain a subrate synchronizing
bit (bit#1) and six data bits (bits 2 through 7). The
eighth bit is set to 1 to ensure meeting the 1s density
DS-1: 1.544 Mb/s.
DS-1C: 3.152 Mb/s.
DS-2: 6.312 Mb/s.
DS-3: 44.736 Mb/s.
DS-4: 274.176 Mb/s.
DS-4A: 139.264 Mb/s.
DVB (DIGITAL VIDEO BROADCAST): A suite of digital video standards
formulated by the European Launch Group (ELG). The standard is
based on MPEG II video. MPEG II/DVB uses the Musicam audio
standard (see also DCII).
EIRP (EFFECTIVE ISOTROPIC RADIATED POWER): The arithmetic product
(expressed as dBW) of, (a) the power supplied to an antenna and
(b) its gain. (GSA, 1996)
ELECTROMAGNETIC SPECTRUM: The entire range of frequencies of
electromagnetic radiation from zero to infinity which measure
electromagnetic energy. The Radio spectrum(less than 300 GHz
bandwidth) is divided into subsets of various bandwidths which
are identified by their frequency characteristics. For example,
the Ku-band subset includes those frequencies of the radio
frequency (RF) spectrum between 10.7 GHz and 17.8 GHz while the
C-band subset includes those frequencies between 3600 MHz and
7075 MHz. (See Figure 1)
ENCAPSULATOR: An IP gateway at a satellite uplink or
cable/wireless headend which is a router taking traffic from the
terrestrial network and routing packets to the satellite WAN
(Wide Area Network). The encapsulator offers streaming
capabilities that encapsulate content into datagrams and then
route it to subscriber subnets. (Satellite Communications, Oct.,
ENCRYPTION: The action of disguising information so that it can
be recovered relatively easily by persons who have the key, but
is highly resistant to recovery by persons who do not have the
key. Encryption is accomplished by scrambling the bits,
characters, works or phrases in the original message. (Carne,
EQUIVALENT NOISE TEMPERATURE: The temperature, usually expressed
in Kelvins, of a hypothetical matched resistance at the input of
an assumed noiseless device, such as a noiseless amplifier, that
would account for the measured output noise. (GSA, 1996)
ETHERNET: A standard protocol (IEEE 802.3) for a 10 Mb/s baseband
LAN (local area network) bus using carrier-sense multiple access
with collision detection (CSMA/CD) as the access method,
implemented at the Physical Layer in the ISO Open Systems
Interconnection-Reference Model, establishing the physical
characteristics of the CSMA/CD network. (GSA, 1996)
ETHERNET CABLE: Cable transmission medium for Ethernet classified
as XbaseY, where X is the data rate in Mb/s, base means
baseband (as opposed to radio frequency) and Y is the category of
cabling. The original cable was 10base5. Common XbaseY Ethernet
Cable Classifications include:
10baseT: A variant of Ethernet which allows stations to be
attached via twisted pair cable.
10base2: The variant of Ethernet that uses thin coaxial
cable (RG-58 or similar)limited to a maximum single
cable length of 200 meters; (sometimes referred to as
10base5: The original full spec variant of Ethernet cable,
using a stiff, large diameter coaxial cable with an
impedance of 50 ohms and with multiple shielding.
Maximum cable length is limited to 500 meters;
(Sometimes referred to as thicknet or thick
100BaseT: Any of several Fast Ethernet 100 Mb/s, CSMA/CD
(Carrier Sense Multiple Access/Collision Detect)
standards for twisted pair cables including: 100BaseTx
(100 Mb/s over two-pair Category 5 or better
cable),100BaseT4(100 Mb/s over four-pair Category 3 or
better cable and 100BaseT2 (100 Mb/s over two-pair
Category 3 or better cable). All are standards under
100Base FX: Fast Ethernet over optical fibre.
100Base VG: A 100 Mb/s Ethernet standard specified to run
over four pairs of Category 3 UTP(Unshielded Twisted
Pair) wires (known as Voice Grade or VG). It is also
called 100VG-AnyLAN because it was defined to carry
both Ethernet and token ring frame types.
FCC (FEDERAL COMMUNICATIONS COMMISSION): This is the national
regulatory body for interstate telecommunications in the United
States. The commission consists of five members all nominated to
a specific term by the President of the United States and
confirmed by the Senate. The current chairperson is William
Kennard. The authority for the commission is contained within the
Communications Act of 1934 as amended (most notably by the
Telecommunications Act of 1996).
FDMA (FREQUENCY DIVISION MULTIPLE ACCESS): See (MULTIPLE ACCESS).
FEC (FORWARD ERROR CORRECTION): A technique which employs special
codes that allow the receiver to detect and correct a limited
number of errors without referring to the transmitter. (Carne,
FM (FREQUENCY MODULATION): Modulation in which the instantaneous
frequency of a sine wave carrier is caused to depart from the
center frequency by a amount proportional to the instantaneous
value of the modulating signal. In FM, the carrier frequency is
called the center frequency. In optical communications, even if
the electrical baseband signal is used to frequency-modulate an
electrical carrier, it is still the intensity of the lightwave
that is varied (modulated) by the electrical FM carrier. The
lightwave is varied in intensity at an instantaneous rate
corresponding to the instantaneous frequency of the electrical
carrier. (GSA, 1996)
FSS (FIXED SATELLITE SERVICE): The segment of Ku-band satellite
service established by the FCC to be provided from medium power
satellites. These satellites are separated in orbit by at least 2
degrees. RF signals are transmitted to FSS satellites in the
14 GHz to 14.5 GHz range and received from the satellite in the
11.7 GHz to 12.2 GHz range.
GAIN: The ratio of output current, voltage or power to input
current, voltage or power, respectively. Gain is usually
expressed in dB. If the ratio is less than unity, the gain
expressed in dB, will be negative, in which case there is a loss
between input and output. (GSA, 1996)
GEO (GEOSYNCHRONOUS EARTH ORBIT): This is the orbital altitude of
35,580 km (22,237 miles) above the earth's surface where a
satellite's velocity matches with the rotation of the earth. A
satellite which is in a GEO position above the earth's equator
(geostationary) will appear from the earth to be occupying a
stationary position. The geosynchronous earth orbit is also
referred to as the Clarke Orbit (named in honor of Arthur C.
Clarke, a science fiction writer who first postulated the
characteristics of this orbit in 1945).
GMT (GREENWICH MERIDIAN TIME): The time zone which includes
Greenwich, England, and which is bisected by 0 Degree Longitude.
This is the time notation which is used for booking international
satellite time. (also referred to as ZULU Time)
GROUND SEGMENT: A term which describes that portion of the total
communications satellite system which is situated on the earth
such as transmitting and receiving antenna, RF (radio frequency)
signal generating facilities, RF receivers and digital encoding
equipment and decoders.
G/T (GAIN TO NOISE TEMPERATURE): In the characterization of
antenna performance, a figure of merit, where G is the antenna
gain in dB (decibels) at the receive frequency, and T is the
equivalent noise temperature of the receiving system in Kelvin.
GUARD BAND: Referring to the frequency that is left vacant
between two channels. The margin of safety that is provided
helps to insure that adjacent signals do not interfere with one
HDTV (HIGH DEFINITION TELEVISION): The term refers to the new
format of digital signal to be seen on the television screen. The
HDTV format will be delivered by the ATV (Advanced Television)
digital system developed by the members of the Grand Alliance
(AT&T, David Sarnoff Research Center, General Instrument,
Massachusetts Institute of Technology, North American Philips,
Thomson Consumer Electronics and Zenith Electronics). This new
system will provide a television picture with about 1000
scanlines per picture (compared to 525 for existing standard) and
a picture aspect ratio of 16:9 (compared to 4:3 for existing
standard). This format will be broadcast over the UHF spectrum.
HERTZ (Hz): A basic measurement of the frequency of an electrical
signal equal to one cycle per second.
KILOHERTZ (KHz): one Thousand cycles/second (10p3)
MEGAHERTZ (MHz): one Million cycles/second (10p6)
GIGAHERTZ (GHz): one Billion cycles/second (10p9)
TERAHERTZ (THz): one Trillion cycles/second (10p12)
PETAHERTZ (PHz): one Quadrillion cycles/second (10p15)
EXAHERTZ (EHz): one Quintillion cycles/second (10p18)
An electromagnetic wave oscillates from positive to negative
poles. An oscillation from positive to negative and back to
positive again is one complete cycle.
HIGH-POWER SATELLITE: A satellite with greater than 100 Watts of
transponder radio frequency (RF) transmitting power.
ICANN (INTERNET CORPORATION FOR ASSIGNED NAMES & NUMBERS):
organization established by the United States Department of
Commerce in 1998 to oversee how Internet names are awarded.
IEEE (INSTITUTE OF ELECTRICAL AND ELECTRONIC ENGINEERS, INC.): A
USA based international technical/professional society founded in
1884. The IEEE promotes standardization in technical disciplines
which include aerospace, biomedical technology, computers and
communications, consumer electronics and electrical power. The
institute conducts educational programs, sponsors international
technical conferences and symposia and publishes nearly 25% of
the world s technical papers in electronics and computer
engineering and computer science.
IEEE 802: A set of IEEE standards applicable to local area
networks, The equivalent ISO standard is IS 8802.
IEEE 802.2: Defines Logical Link Control (LLC, the upper
portion of the data link layer) for local area
IEEE 802.3: Defines the transport layer of (a variant of)
IEEE 802.3u: The IEEE committee working on standards for
IEEE 802.3z: The IEEE committee working on standards for
IEEE 802.4: Token Bus standard.
IEEE 802.5: Token ring standard.
INCLINED ORBIT: A condition in which a satellite is unable to
maintain a geostationary position above the earth's equator.
Almost all satellites generate electrical power to operate their
transponders by converting the sun's energy to electricity.
Energy used for station keeping, that is keeping the satellite
within a very narrow range of movement north or south of the
equator, is stored on board the spacecraft and over time is
dissipated, usually after passage of the design life of between
8-15 years. When this fuel runs out, the satellite is no longer
able to keep station above the equator. Since satellite uplink
and downlink antenna are aimed at a particular point above the
equator, a satellite in inclined orbit will move in and out of
the antenna's "range of vision" as the satellite's orbit
fluctuates north and south of the equator.
INTERLACED SCANNING: The television picture in the NTSC system is
made up of 525 scan lines. One-half of the scan lines which make
up the video picture are traced on the screen approximately 30
times a second alternating with the other one-half of the scan
lines which are traced on the screen approximately 30 times a
second thus providing 60 interlaced line scanning events each
second. (see also PROGRESSIVE SCANNING)
INTERNET: The Internet is the largest interconnection of networks
in the world. It is a three level hierarchy composed of backbone
networks such as ARPAnet, NSFnet and MILNET, mid-level networks,
and stub networks. These include among others commercial (.com
or .co), university and educational (.edu or .ac), other research
networks (.org or .net), governmental (.gov) and military (.mil)
networks and span may different networks around the world with
various protocols including the Internet Protocol. (Howe, 1999)
IP (INTERNET PROTOCOL): See TCP/IP.
IRD (INTEGRATED RECEIVER/DECODER): Satellite ground segment
equipment which receives and decodes digital information
transmitted via satellite RF signals. Manufactures have until
now incorporated proprietary algorithms into digital transmission
systems which result in the lack of interoperability among the
differing systems. An IRD will only operate successfully within
the particular proprietary system of which it is a part.
ISL (INTER-SATELLITE LINK): A satellite architecture whereby two
or more satellites are configured in such a way that they may
communicate directly with one another. This architecture is used
in the TDRESS system of satellites and is a component of the
design of Big LEO communications satellite systems.
ISDN (INTEGRATED SERVICES DIGITAL NETWORK): A standard for the
integrated transmission of voice, video and data developed by the
Consultative Committee on International Telephony and Telegraphy
(referred to as the CCITT now combined with the CCIR,
Consultative Committee on International Radio to form the TSS,
Telecommunications Standardization Sector). The ISDN bandwidths
include the Basic Rate Interface or BRI at 144 Kb/s and the
Primary Rate Interface or PRI at 1.544 and 2.048 MB/s (see T-l
ISO (INTERNATIONAL STANDARDS ORGANIZATION): An international
organization which developed the MPEG and JPEG standards and
which is closely allied with the CCITT (part of the
Telecommunications Standardization Sector, TSS)
ITU (INTERNATIONAL TELECOMMUNICATIONS UNION): A United Nations
treaty organization(originally created in 1865 as the
International Telegraph Union with a membership of twenty
nations...current name adopted in 1932) which supports procedures
for the international allocation of the radio frequency (RF)
spectrum and provides the platform for the World Radio Conference
(WRC), a biannual meeting of world communication leaders. The WRC
publishes 'International Radio Regulations' for the RF spectrum.
The ITU conducts ongoing policy and study group sessions.
ITU-T MULTIMEDIA TELECONFERENCING STANDARDS: Standards developed
and ratified by the Telecommunication Standardization Sector of
the International Telecommunications Union which define the core
technologies for multimedia teleconferencing. Standards are
developed to promote interoperability among different proprietary
systems. These core standards include:
T.120: Data protocols for Real Time Data Conferencing
(Audiographics). These standards cover document
conferencing and application sharing.
H.320: Governs the basic video-telephony concepts of
audio, video and graphical communications over circuitswitched
media such as ISDN.
H.323: An extension of the H.320 Standard to provide for
multimedia telecommunications over intranets and
packet-swithched networks generally -- applicable to
the use of video and other communications over the
Internet. Provides standards for both reliable and
unreliable transmission over the Internet.
H.324: Addresses and specifies a common method of sharing
video, data, and voice simultaneously using V.34 modem
connections over single analog POTS (Plain Old
Telephone Service) line.
IXC (INTEREXCHANGE CARRIER): Provides long-distance transport
services between points-of-presence (POP) that are established
for each local exchange carrier. (Carne, 1995)
JPEG (JOINT PICTURE EXPERTS GROUP): A subgroup of the ISO which
has established international standards for the digital
compression of still pictures.
KA-BAND: A portion of the RF spectrum located between 18 GHz and
31 GHz. Downlink frequencies for satellite communications are
located in the 20 GHz range and uplink frequencies are located in
the 30 GHz range.
KU-BAND: A portion of the RF spectrum located between 10.9 GHz
and 17 GHz, a part of which is dedicated to satellite
communications. Satellite downlink frequencies are located
between 11.7 GHz and 12.2 GHz and uplink frequencies are located
between 14 GHz and 14.5 GHz.
LAN (LOCAL AREA NETWORK): A bus or ring connected, limited
distance network that serves the data communication needs of
users within a building or several buildings in proximity to each
other. (Carne, 1995) Ethernet is an example of a standard Local
LATA (LOCAL ACCESS AND TRANSPORT AREA): A grouping of exchange
areas served by a single Local Exchange Carrier (LEC). Traffic
between LATAs must be carried by an Inter-Exchange Carrier (IXC).
L-BAND: A portion of the RF spectrum located between 500 MHz and
1500 MHz. The RF (radio frequency) spectrum between 950 MHz and
1450 MHz is dedicated to mobile communications.
LCD (LIQUID-CRYSTAL DISPLAY): An electronic display panel that is
based on the properties of a liquid-crystal material sandwiched
between two transparent plates and illuminated from behind. The
transmittance of the liquid-crystal material changes with the
applied electric field. (Inglis $ Luther, 1996)
LEC (LOCAL EXCHANGE CARRIER): Provides public, switched telephone
services within limited areas called Local Access and Transport
Areas (LATA). The LEC provides connections between users located
within the same exchange area, between users located in different
exchange areas that are in the same LATA, and delivers traffic
directed to an exchange area outside the LATA to Inter-
Exchange Carriers (IXC). (Carne, 1995)
LEO (LOW EARTH ORBIT): Until recently, a distinction was made
between LEO and MEO (Medium Earth Orbit) orbital classifications.
LEO was classified as an earth orbit with an altitude of between
200-2400 kms. The MEO designation classified orbits between 2,400
and 10,000 km. Current literature frequently refers to any
orbital distances from earth of less than that for geostationary
orbit as being LEO. Almost all of the Big LEO and Little LEO
systems which are currently planned will operate in orbits
ranging between 640 km and 2,500 km above the earth.
Satellites which are placed in LEO orbits move rather swiftly in
relation to the earth, generally from a westerly to an easterly
direction. Some of the newly designed LEO communications
satellite networks will launch some of the satellites in the
network constellation into polar earth orbits. The relative
motion of the satellite in relation to the earth slows as the
altitude of the satellite increases. The rapid relative movement
in low earth orbit enables data gathering and communication
satellites to cover large areas of the earth's surface in short
periods of time. The space shuttle is injected into a low earth
orbit, for example.
BIG LEO: A space segment architecture which consists of a
constellation of many satellites in Low Earth Orbit in a
configuration which will permit the delivery of global
mobile telephony and data services. The system is served by
a network of ground stations which provides gateway access
from terrestrial networks as well as management, control and
orbital correction functions. This system is intended to
provide telecommunication service to remote sites, high
latitude geographic locations which are not accessible by
GEO satellites and to omnidirectional antenna on handset
transceivers. Examples of Big LEO systems include Teledesic
LITTLE LEO: A space segment architecture which is similar
to that of Big LEO systems but which carries data only. The
remote collection and transmission of utility meter data
would be an example of a service provided by a Little LEO
satellite system. Often, store and forward technology is
used to facilitate communication with the ground segment.
LMDS (LOCAL MULTIPOINT DISTRIBUTION SYSTEM): A fixed, broadband
point-to-multipoint wireless service which can provide one-way
and two-way high capacity voice, video and data service. Services
are licensed and bandwidth auctioned by the FCC. Service rules
were adopted by the FCC in March, 1997.
LOW-POWER SATELLITE: A satellite with less than 30 Watts of
transponder radio frequency (RF) transmitting power.
LUMINANCE: In color video systems, a component signal that
represents the brightness of the image. (Inglis & Luther, 1996)
MEDIUM-POWER SATELLITE: A satellite with greater than 30 Watts
but less than 100 Watts of transponder radio frequency (RF)
MEO (MEDIUM EARTH ORBIT): See LEO (LOW EARTH ORBIT).
MID BAND: A portion of the VHF (Very High Frequency) RF spectrum
located between television channels 6 and 7 (88 MHZ to 174 MHZ)
which has been reserved by the FCC for air, maritime and land
mobile units, FM radio and aeronautical and maritime navigation.
The frequencies between 108 MHZ and 174 MHZ can be used to
provide additional channels on cable television systems.
MODEM: This term is a contraction of modulator and
demodulator . A modem coverts digital data generated by and
coming into a computer which are transmitted over telephony
circuits or by using terrestrial or satellite RF (radio
MODULATION: The process of modifying the channel signal (often
called the carrier ) to represent information to be transmitted.
Typical modulation methods involve the frequency, amplitude or
phase of the carrier. (Inglis & Luther, 1996)
MPEG (MOTION PICTURE EXPERTS GROUP): A working group of a
committee of the ISO (International Standards Organization).
They developed the MPEG worldwide standard for motion video
compression and transport. (Inglis & Luther, 1996)
MTOPS (MILLIONS OF THEORETICAL OPERATIONS PER SECOND): A measure
of computer processing speed used by the US Department of
Commerce (USDoC) to define a classification system for export
controls applicable to high-speed computers. For example, in
February, 2000, the USDoC eliminated export controls on computers
with speeds below 12,300 MTOPS to all countries with the
exception of Iraq, Libya, North Korea,Cuba, Sudan and Syria.
MULTIPLE ACCESS: Techniques have been developed in the satellite
industry which allow satellite spectrum and power to be shared
efficiently among multiple users of a satellite transponder.
CDMA (CODE DIVISION MULTIPLE ACCESS): A multiple access
scheme whereby ground station uplinks access a satellite
transponder using spread-spectrum modulations and orthogonal
codes to avoid interfering with other transmissions using
the same transponder. In contrast with the FDMA scheme which
attempts to minimize the transmitted bandwidth, in this
scheme all users transmit signals simultaneously across all
of the dedicated multiple access channel. Receivers use a
code corresponding to the transmission code to demodulate
the signal or separate it from other signals on the channel.
FDMA (FREQUENCY DIVISION MULTIPLE ACCESS): A multiple access
scheme whereby each ground station uplink is assigned a
specific frequency slot and bandwidth for one of the
multiple carriers within a specific satellite transponder.
This scheme is usually used in conjunction with Frequency
Modulation. The FDMA scheme may be divided into two
categories, Multiple Channel Per Carrier (see MCPC) and
Single Channel Per Carrier (see SCPC).
TDMA (TIME DIVISION MULTIPLE ACCESS): A multiple access
scheme whereby many users may access a single carrier by
time sharing. A digital signal is compressed in packets
which are transmitted to the carrier in bursts. These
packets are processed into consecutive time segments which
do not overlap. Instructions are sent to a receiver which
identify the packets representing a particular transmission
(ie., every 4th packet).
MULTIPLEXING: A process in the transmission of RF (radio
frequency) signals whereby a number of simultaneous transmissions
can be accommodated on a single circuit.
NAS (NETWORK-ATTACHED STORAGE): A device used to enlarge the
reserve of shared storage space. Also used to accelerate Web page
transfer speeds through caching.
NETWORK LAYER: (See OSI)
NOISE: 1. An undesired disturbance with the frequency band of
interest; the summation of unwanted or disturbing energy
introduced into a communication system form man-made and natural
sources. 2. A disturbance that affects a signal and that may
distort the information carried by the signal. 3. Random
variations of one or more characteristics of any entity such as
voltage, current or data. 4. A random signal of known
statistical properties of amplitude, distribution and spectral
density. 5. Loosely, any disturbance to interfere with the
normal operation of a device or system. (GSA, 1996) (See
EFFECTIVE NOISE TEMPERATURE)
NTSC (NATIONAL TELEVISION SYSTEMS COMMITTEE): The organization
(RCA/NBC) which established the standards for the television
broadcast system in the United States. A close approximation of
this system was also adopted in Japan. The US and Japanese video
systems are now referred to as NTSC systems. This video
standard provides for a screen density of 525 scanlines per
picture and operates at 60 cycles per second. This system was
developed so that existing black and white (B/W) mono audio
television receivers would be compatible with color stereo audio
OC-N (OPTICAL CARRIER LEVEL-N): The optical equivalent of (STS-N)
Typical OC Levels are:
OC-1: 51.84 Mb/s.
OC-3: 155.52 Mb/s.
OC-12: 622.08 Mb/s.
OC-24: 1.244 Gb/s.
OC-48: 2.488 Gb/s.
OC-96: 4.976 Gb/s.
See: STS-N (SYNCHRONOUS TRANSPORT SIGNAL -- LEVEL N) and SONET
(SYNCHRONOUS OPTICAL NETWORK). (Carne, 1995)
OSA (OPEN SYSTEMS ARCHITECTURE): Permits transparent
communication between cooperating machines. OSA is embodied in
international standards referred to as the Open Systems
Interconnection Reference Model (OSI). (Carne, 1995)
OSI (OPEN SYSTEMS INTERCONNECTION REFERENCE MODEL): The reference
model, also referred to as OSIRM, provides a framework for
communication that relies on standard non-proprietary
interconnection protocols (protocol stack). It consists of seven
layers that serve to decompose the complexity of information flow
between cooperating machines into consecutive steps that are
substantially independent of each other. (Carne, 1995)
The seven OSI model layers are:
Layer #7 Application (User): Handles issues like network
transparency, resource allocation and problem
partitioning. The application layer is concerned
with the user s view of the network (e.g.
formatting electronic mail messages). The
presentation layer provides the application layer
with a familiar local representation of data
independent of the format used on the network.
Layer #6 Presentation: Performs functions such as text
compression, code or format conversion to try to
smooth out differences between hosts. Allows
incompatible processes in the application layer to
communicate via the session layer.
Layer #5 Session: Uses the transport layer to establish a
connection between processes on different hosts.
It handles security and creation of the session.
It is used by the presentation layer.
Layer #4 Transport: Determines how to use the network layer
to provide a virtual error-free, point to point
connection so that host A can send messages to
host B and they will arrive un-corrupted and in
the correct order. It establishes and dissolves
connections between hosts. It is used by the
Layer #3 Network: Determines routing of packets or data
from sender to receiver via the data link layer
and is used by the transport layer. The most
common network layer protocol is IP.
Layer #2 Data Link: Splits data into frames for sending on
the physical layer and receives acknowledgment
frames. It performs error checking and retransmits
frames not received correctly. It
provides an error-free virtual channel to the
Layer #1 Physical: Concerning electrical and mechanical
connections to the network. Examples of physical
layer protocols are CSMA/CD, token ring and bus.
Note: Compare with the layers of the TCP/IP protocol suite.(Howe,
PACKET: A sequence of bits that is divided into two parts -- one
contains the user s information, and the other contains control
information. (Carne, 1995)
PACKET JITTER: (see PACKET LOSS)
PACKET LOSS: Packet Loss and Packet Jitter are types of
degradation in the delivery stream of digital information which
result from unfavorable network conditions such as extremely
heavy or bursty traffic. Individual packets comprising the data
stream can arrive early, late or out of sequence causing unstable
video reception, pauses, the appearance of artifacts or the loss
of the data altogether.
PAL (PHASE ALTERATION SYSTEM): A German developed color
television standard which provides for a screen density of 625
scanlines per picture and which operates at 50 cycles per second.
This system is common in the UK, much of Europe, Africa, Asia and
Oceania and is incompatible with the North American and Japanese
NTSC standards. The IntelSat satellite system often employs the
PERIGEE: The point in an elliptical satellite orbit where it is
closest to the center of the earth (the opposite of APOGEE).
POP (POINT-OF-PRESENCE): In the field of telephony, POP refers
to the facility interface between the Local Exchange Carrier
(LEC) and the Inter-Exchange Carrier (IXC). A POP must be
established on each trunk path that connects switches that belong
to the local and long-distance carriers. On one side of the POP,
the LEC is responsible for service; on the other side, the IXC is
responsible (Carne, 1995)
PROGRESSIVE SCANNING: The method for tracing scan lines onto a
computer monitor whereby all scanlines are presented in sequence
60 or more times per second. Unlike the NTSC video standard,
there is no single standard for computer display. Most computer
monitors will accept a wide range of screen resolutions and
scanning rates utilizing multiscan technologies. (see also
QPSK (QUADRATURE PHASE SHIFT KEYING): Used to modulate digital
information onto an RF carrier when satellite transponders are
used to transmit MPEG 2 signals. Rather than using the
amplitude or frequency of the carrier to convey the information,
QPSK modulates the phase of the carrier signal. Depending on the
data being modulated, the carrier is forced into one of four
different phase states known as a symbol. The advantage of this
method is that each symbol contains two data bits, thus doubling
the potential amount of data that is transmitted over
conventional amplitude or frequency modulation techniques.
RAM (RANDOM ACCESS MEMORY): In computers, the main system memory,
usually consisting of volatile memory (memory that loses its data
when power is removed) solid-state chips.
(Inglis & Luther, 1996)
RBOC (REGIONAL BELL OPERATING COMPANY): An independent common
carrier that provides local exchange services within specific
areas. The term originally referred to the local telephony
service companies which were created as a result of the break-up
of AT&T in 1984. The term now refers to all local exchange
services. (Carne, 1995)
RF (RADIO FREQUENCY): Any frequency within the electromagnetic
spectrum normally assiciated with radio wave propagation.
Organizations such as the FCC and ITU have divided the radio
frequency spectrum into subdivisions for management purposes.
ROM (READ-ONLY MEMORY): In computers, nonvolatile memory (memory
that retains its stored data when power is removed that stores
permanent programs. ROM usually consists of solid-state chips.
(Inglis & Luther, 1996)
SAR (SPECIFIC ABSORPTION RATE): Measures the maximum quantity of
radiation absorbed by one Kilogram of tissue from a cell phone.
Nokia, Motorola and Ericsson are working to establish
international benchmark standards.
SDH (SYNCHRONOUS DIGITAL HIERARCHY): An international digital
telecommunications network hierarchy which standardizes
transmission around the bit rate of 51.84 megabits per second,
which is also called STS-1. Multiples of this bit rate comprise
higher bit rate streams. SONET is the American version of SDH.
SECAM (SEQUENTIAL ENCODED COLOR AMPLITUDE MODULATION): A French
developed color television standard which is common in
Francophile countries and the former Soviet Union. The system
operates with a screen density of 625 scanlines per picture and
50 cycles per second but inverts the signal making it
incompatible with the PAL and NTSC video standards.
SONET (SYNCHRONOUS OPTICAL NETWORK): A synchronous digital
network that employs optical fibers (exclusively). Each facility
conforms to standards that include electrical and optical speeds,
and frame formats. (Carne, 1995) SONET carries circuit-switched
data in frames at speeds in multiples of 51.84 megabits per
second. SDH is the international term for SONET. (Howe, 1999)
SPACE SEGMENT: A term which describes the portion of the total
communications satellite system which is physically located in
orbit around the earth.
SPECTRUM: A short-hand reference to the ELECTROMAGNETIC SPECTRUM.
(See Figure 1.)
STS-N (SYNCHRONOUS TRANSPORT SIGNAL -- LEVEL N): In SONET, a
frame of N x 6480 bits that is transported at N x 51.84 Mb/s.
STS-N signals are created by interleaving N STS-1 signals, octetby-
octet. For various reasons, the values of N + 3, 12, 24, 48
and 96 are preferred. The optical equivalent OF STS Levels are
expressed as OC-N levels. (Carne, 1995)
T-1 LINE: A transmission medium with a transmission bit rate of
1.544 million bits per second (Mb/s), equivalent to the ISDN
Primary Rate Interface (PRI) for the United States. The European
T-1 transmission bit rate is 2.048 Mb/s.
TCP/IP (TRANSMISSION CONTROL PROTOCOL over INTERNET PROTOCOL):
The de facto standard Ethernet protocols incorporated into 4.2BSD
(Berkeley System Distribution-Version 4.2) Unix. TCP/IP was
developed by DARPA (Defense Advanced Research Projects Agency)
for internetworking and encompass both network layer and
transport layer protocols. While TCP and IP specify two protocols
at specific protocol layers, TCP/IP suite is often used to refer
to the entire DoD (Department of Defense) protocol suite based
upon these, including telnet (Remote Terminal Protocol), FTP
(File Transfer Protocol) and UDP (User Datagram Protocol). (Howe,
TCP (Transmission Control Protocol): The most common
transport layer protocol used on the Ethernet and the
Internet. TCP is built on top of IP (Internet Protocol)
and is nearly always seen in the combination TCP/IP.
It adds reliable communication, flow control,
multiplexing and connection-oriented communication. It
provides full-duplex, process-to-process connections.
IP (Internet Protocol): The network layer for the TCP/IP
protocol suite widely used on Ethernet networks. IP is
a connectionless, best-effort packet switching
protocol. It provides packet routing, fragmentation
and re-assembly through the data link layer.
TCP/IP SUITE: Members of the Internet community share a family of
protocols called TCP/IP. The name is shorthand for a suite of
protocols whose major members are TCP (transmission control
protocol), a transmission layer procedure, and IP (internet
protocol), a network layer procedure.
The five Layers of the TCP/IP suite of protocols are:
Application Layer: Interfaces user processes with lower
Transport Layer: Contains protocols that establish, control
and terminate network connections between data
structure endpoints on source and destination hosts
Internet Layer: Implements addressing that supports
communication between network devices and provides
routing for transmitting data between networks (IP
Datalink Layer: Employs HDLC (High-level Data Link Control),
LAP-B (Link Access Protocol-Balanced), LAP-D (Link
Access Procedure on the D channel) and IEEE 802.2
Physical Layer: Incorporates a wide range of physical
interfaces such as EIA232/449 (Electronics Industry
Association; Standard RS-232/449), ISDN (Integrated
Services Digital Network), IEEE 802 and ITU-T V.35
(International Telecommunications Union-
Telecommunications Standards Sector; Standard V.35).
See also OSI (Open Systems Interconnection) Layers.
TDMA (TIME DIVISION MULTIPLE ACCESS): See MULTIPLE ACCESS.
TOKEN-RING LOCAL AREA NETWORK: A computer LAN arbitration scheme
in which conflicts in the transmission of messages are avoided by
the granting of tokens which give permission to send. A
station keeps the token while transmitting a message, if it has a
message to transmit, and then passes it on to the next station.
Often, Token Ring is used to refer to the IEEE 802.5 token ring
standard which is the most common type of token ring. (Howe,
1999) -- A LAN in which each station is connected to two others
so as to form a single-thread loop that connects all of the
stations. Data is transferred around the ring from station to
station. (Carne, 1995)
TRANSPONDER: A combination receiving and transmitting antenna on
a communications satellite. A frequency converter is also
including in the transmit/receive package which converts the
uplinked signal frequency to a transmission or downlink
TRANSPORT LAYER: (See OSI)
UNIX: An interactive time-sharing operating system (OS) invented
in 1969 by Ken Thompson of Bell Labs. Twenty-two years after its
invention, Unix had become the most widely used multi-user
general-purpose operating system in the world. It was the first
source-portable OS. Unix is now offered by many manufactures and
is the subject of an international standardization effort with
the Unix trademark being owned by X/Open. A Unix reference desk
may be found at <http://www.geek-girl.com/unix.html>.
USAT (ULTRA SMALL APERTURE TERMINAL): Earth station satellite
antenna with a diameter or cross-section dimension of about 50 cm
VGA (VIDEO GRAPHICS ADAPTER): A video display standard for
computer monitors which evolved from the CGA (computer graphics
adapter) and EGA (enhanced graphics adapter) standards of the
early 1980's. In 1987, IBM introduced the PC-AT computer which
adopted a new display standard called VGA which allowed computer
monitors to show integrated lifelike pictures using multiple
shades of color. This standard uses progressive line scanning.
VSAT (VERY SMALL APERTURE
Repairs on Televisions should be done by an authorized repair tech. There are high voltages that remain charged inside capacitors on the boards. Lack of knowedge of how to handle these boards could result in getting shocked.
When I press my power button on my remote control it does not respond. Is it my TV or remote control?
You can check your remote control with your cell phone video camera.
Aim your remote into your camera while looking at the camera. You should see a purple beam comming from the end of your remote while your holding down the power button. This will tell you that your batteries are good and your problem is with the TV.
It can, However, You may need a commercial factory remote. Also, some of the menus will look different and have features like ways tolock out the front buttons.
You don't half all the pieces of the equation figured out yet!
Most Consumer electronics are designed with multiple circuit boards inside. Some boards are available and some discontinued. Many of these boards are tied together to make up the entire final assembly. These may be found in Radios, TV's, Games, or Computers. Due to the fact that the circuits are arranged to be supported off of one another many repair actions have to be in successive order. ie..Replace this to see if the next circuit is good or bad. Kind of like the doctor treating allot of possibilities in hopes to land on the right medicine. Does'nt mean your cured. He just know what it's NOT. We also sometimes have to replace boards to get to a final diagnoses.
We charge a small fee of $75 for diagnoses up front in order to get to the correct answer as to how many boards if any, are bad and how much? The answer in the end may be that It IS worth it if the boards are available and reasonably priced.
Like any investment I look at replaceing only when the repair cost exeeds 51% of the cost of a new product.
If the set clicks and comes on, however the brightness is slow to come on it may be a DLP TV with a defective lamp. Lamps thsat have reached the end of ther life are known to come on slowly when there on there last days.
If it is a flat sceen model, the TV clicks and the set does not come on- The power supply is likey faulty. It is having to warm up like the lamp. this is a sign of a failing power supply componants inside the set and requires new parts.
Not likely, Most flat panel product has there audio amplifiers build onto the Main Board of the set. Fixing this is usually not the option due to the other IC chips being so close to the audio circuit. DE soldering ruins the board. Usually a Main Board replacement to fix.
This is true, However, Not always for the reasons you think. Capacitors are rated by voltage and Fareds and are usually spec-out by the energy consumption during normal oporation.
Here's the problem they can fail for number of reasons;
Voltages can be irratic off the street can vary during bad weather, irratic when sharing electrical appliances such as portable air conditioners and refridgerators that have a compressor and Irratic when hooking up generators. These devices are know to spike voltages causing capacitor damage.
The equipment has reached its end off life. Capacitors have liquid in them and it evapoartes after many years with use. Most electronics should last 5-12 years based on the temperature of the equipment. The hotter the electronics the fast the liquid evaporates from the capacitors.
The temperature of electronics can very from enviroments. Things like dust clogging vents, Equipment placed too close to fireplaces or heaters, euipment placed in cubbies that surround the device can all directly impact the rate of heat dispursion inside a electronic piece of equipment and shorten the life of a capacitor.
The manufacture could have used the wrong values in there circuit
The load that the circuit carries has increased due to the deteriation of other elecronics in the equipment. example: Plasma panels can cause power supplies to blow caps when panel dies.
RF Electronics Glossary
AC: (Alternating current): Electricity can travel in either direction through a wire. Electricity from a power station constantly alternates from one direction to the other and this is referred to as alternating current electricity. When A.C. electricity has traveled once in both directions that is called a 'cycle'. The number of cycles per second is referred to as the frequency. British power stations generate A.C. electricity at a frequency of 50 cycles per second or 50Hz (Hertz).
AES:Automatic electronic shutter
AGC: Automatic gain control:An electric circuit that automatically controls the amplitude of a video signal to an appropriate, preset level.
Amp hours: Term used to determine how long a battery will last. I.E 1000mA = 1 AMP Hour. A battery with a 1 AMP hour capacity would run a device drawing 1000mA for 1 hour.
Angle of view: The degree to which a lens aperture can film, Measured as a percentage of 360 degrees.
Analog: An information representation scheme with continuous amplitudes. Contrasts with digital, where information is quantified into discrete steps.
Analog-to-digital (A/D): Converter: A component or piece of equipment used to convert analog video to discrete digital signals. As used in computer processing.
Aperture: In a video camera or monitor, the aperture refers to the size and shape of the electron beam that lands on the target or phosphor. In an optical instrument, the opening of a lens or aperture stop.
Aspect ratio: The ratio of width to height for the frame of the video picture. It is 4:3 for both the US and European closed circuit (RS-179 and CCIR) and broadcast (NTSC and PAL) standards.
Auto black: A video camera circuit that automatically adjusts the signal black level to the darkest region of the picture regardless of its absolute brightness.
Automatic iris: Lens diaphragm which is controlled by a mechanism in the camera body coupled to the shutter release. The diaphragm closes to any preset value before the shutter opens and returns to the fully open position when the shutter closes.
Automatic shutter control:Built in exposure meter that automatically adjusts the lens opening, shutter speed, or both (program) from proper exposure.
Back light compensation: A circuit designed to compensate for light coming from behind the subject in the cameras view, toward the camera lens. Helps reduce silhouette and lens flaring affects.
Bandwidth: The difference between the upper and lower limit of a frequency band expressed in number of cycles per second (hertz). In video, the signal bandwidth directly affects the horizontal resolution of the picture. 1 MHz of bandwidth is required for every 80 TV lines of resolution. Part of the frequency spectrum; that part of the spectrum required for a specific purpose. The greater the bandwidth, the more information that can be sent through: e.g. a television channel occupies a bandwidth of up to 8 Megahertz, (MHz), where as a telephone conversation utilizes only 4 kilohertz (kHz).
Black level: The small video signal voltage (usually around 0.05 to 0.1V) that corresponds to a specified limit for black peaks. In a black-negative, composite video signal, the blanking, sync, and other control signals that are not part of the picture signal have voltages below the black level.
Black negative: A standard signal format used in CCTV in which the voltages of the picture black level and sync signals are lower that the white levels of the picture signal.
BNC connector: A coaxial type of connector used to couple coaxial cables to video and other high-frequency electronic equipment.
B&Whttp://www.videoessentials.com/glossary.htm#B" href="http://www.videoessentials.com/glossary.htm#B" target="_blank">: (black and white) Monochrome, as contrasted to color video.
Binary: Means "Two" or Base two. The binary system is a way of counting using just the two numbers 0 and 1. Digital devices use the Binary system.
Bit: A contraction of Binary Digit, the smallest unit of information in a notation using the binary system (1 or 0). A byte is commonly made up of 8 bits.
Board lens: Small diameter fixed or vari-focal lens. Common sizes from 2.1mm-12mm.
Board camera: Miniature integrated Circuit Board with CCD imaging chip mounted in the center. Basically a mini Camera without the housing.
Brightness: The relative lightness or darkness of a color.
CCD - Charge Coupled Device: Image sensor which is a large scale integrated circuit containing hundreds of thousands of photo-sites (pixels) which convert light energy to electronic signals. It is light sensitive and forms the imaging device of most modern cameras. Size is measured diagonally and can be 1/4", 1/3",1/2" or 2/3". CCD stands for Charge Coupled Device, which is the new age imaging device, replacing the old image tubes. When first invented in the 1970s, it was initially intended to be used as a memory device. Most often used in cameras, but also in Telephone, fax machines, scanners, etc.
CCIR: International Radio Consultative Committee: Standard used to designate the black and white closed circuit TV formats. Australia, New Zealand and most of Europe.
CCTV: Closed Circuit TV: A video system that does not broadcast TV signals over the air but rather transmits them over a coax cable, Uses standards such as RS-170 and CCIR, EIA, NTSC, PAL etc.
CE: The CE mark is the official marking required by the European Community for all Electric- and Electronic equipment that will be sold, or put into service for the first time, anywhere in the European community. It proves to the buyer -or user- that this product fulfills all essential safety and environmental requirements as they are defined in the so-called European Directives.
Celsius: (C) Temperature Measurement
C-mount: The first standard for CCTV lens screw mounting. It is defined with the thread of 1” (2.54 mm) in diameter and 32 threads/inch, and the back flange-to-CCD distance of 17.526 mm (0.69”). The C-mount description applies to both: lenses and cameras. C-mount lenses can be put on both, C-mount and CS-mount cameras, by adding an adapter ring to reduce this distance to 12.5 mm.
CS- mount: The second standard for CCTV Lens screw mounting. See C-mount this page.
Coaxial cable: Also Coax. An electrical cable with a central conductor surrounded by a low-loss insulating sleeve and insulated ground shield. A coaxial cable is capable of passing very-high-frequency electronic signals with low signal loss and noise pickup.
Composite video signal: A video signal that contains a picture signal, vertical and horizontal blanking, and synchronizing pulses.
Contrast: A measure of the gradation in luminance that provides gray scale (or color) information. Contrast is expressed as the ratio (difference in luminance)/(average luminance) in adjoining areas of the scene. Under optimum conditions, the eye can just detect the presence of 2% contrast.
Covert video camera: A ultra small ccd video camera with a pinhole lens. Suited for installation into nearly any common item for security, surveillance and crime detection purposes. Sold at GCHQ.
CRT: Cathode-ray tube. A vacuum tube in which the electrons emitted by a heated cathode are focused into a beam and directed toward various points on a phosphor-coated surface. The phosphor becomes luminous at the point where the electron beam strikes.
DC: 'Direct Current': - when electricity from a power source travels in one direction only. Electricity from a battery gives direct current through a conductor. Conventionally electricity is said to flow from positive to negative although theoretically the electron flow is from negative to positive.
Decibel (dB): A unit of comparing the strengths of two signals. In video, decibels are the ratio of two signal voltages expressed as 20x log (ratio of the amplitude of the test signal as compared to the second, usually a standard signal). In some applications, power ratios are used; dB (power) is defined as 10 x log (ratio of powers).
Depth of field: The distance between the closest and farthest objects in focus within a scene as viewed by a lens at a particular focus and with given settings. The depth of field varies with the focal length of the lens and its f-stop setting or NA; and the wavelength of light. http://www.cs.ucla.edu/~simonw/DoF/" href="http://www.cs.ucla.edu/~simonw/DoF/">Special calculator available.
Definition: The degree of detail or sharpness in a video picture.
Digital (signal): A signal whose units are represented by either one of only two states: on or off, yes or no, 1 or 0. Since no gradations in between are permitted, digital signals are precise, unambiguous, and quite immune to noise. See also Analog.
Digital Signal Processor (DSP): A microprocessor using Digital architecture
Dimensions: Height x Width x Depth (HxDxW) or similar and expressed in metric or imperial measurements.
Distortion (electronic): In signal processing, the lack of correspondence of the waveforms in the output relative to the incoming signal caused by undesired nonlinear processing. The amplitudes or phases of certain frequency components have changed relative to other frequency components.
Distortion (optical): Geometrical distortion refers to the lack of correspondence of the shape (proportional distances) of the image relative to the image produced by an idealized lens or device. Geometrical distortions are expressed as a percentage of distances departing from the distances in a non-distorted image.
Dome: A dome shaped cctv housing for CCD Cameras.
Dome options: Standard sizes are measured by diameter, 80mm, 100mm and 120mm are the most common dome sizes.
EIA: Electronic Industries Alliance: When applied to this web-site it generally refers to the Standard used in the United States for black and white video. CCIR is the equivalent black and white format for Australia, New Zealand and most of Europe.
Electronic shutter: A mechanical shutter that has had its timing escapement replaced with an electronic timing circuit. This circuit allows a wider range of exposure times, can be more accurate, and, placed in a circuit with a photoconductive cell, allows automatic sensing of shutter speeds.
Electronic video surveillance: Generally a term for capturing video footage of a subject without detection.
Electronic eavesdropping: Listening covertly to communications using electronic bugging equipment.
Electronic spectrum analyzer: A device used to determine other devices operating frequency, commonly used to detect illegal use of the RF spectrum.
Electronic warfare: The term used to describe military spectrum equipment meant to disrupt, destroy or disable enemy radar, communications and technology.
Electronic interception: Electronic interception of fax, voice or data communications by electronic means.
Electronic bug kit: Component level bugging kit, usually FM, but sometimes VHF kits are available. FM kit transmitters can be received on a standard FM radio.
Electronic spectrum jammer: A device that jams transmissions across the Spectrum. Used to protect against unauthorized RF signals transmitting a RF signal within a given area.
Faceplate: The window that the input or output radiation passes through on a camera tube, monitor picture tube and solid state array. Sometimes it is used to support a target or phospher.
False color: Representation in colors differing from the original scene. In the false-color display of a processed video image, colors are assigned to spectrally separated images before recombination to allow multispectral analysis.
FCC: Federal Communications Commission (USA)
Fiber optics coupling: A method used to transfer an image from one imaging device to another. For example. coupling the output image from an image intensifier to a CCD or image pickup tube equipped with a fused fiber optic faceplate. The http://www.telecomosp.com/fiber/dek.htm" href="http://www.telecomosp.com/fiber/dek.htm">fiber optic output faceplate of the intensifier is coupled to the fiber optic input faceplate of the imaging device using a matching index grease.
Field: In video, one vertical sweep of a raster scan. In 1:1, 2:1 and 4:1 interlaced video, one, two, and four fields respectively make up a video frame. See also
Flicker: See Critical Flicker Frequency (CFF)
Focus: The point or plane in which light rays or an electron beam form a minimum sized spot that has the proper intensity distribution. Also the act of bringing light or electron beams to a fine spot.
Foot candle (fc): A measurement of illuminance, or illumination, expressed in lumens per square foot. It is the amount of illumination from 1 international candle (the candela) falling on a 1 ft surface at a distance of 1 ft. In SI units, 1 fc = 10.764 lux (1x).
Format, video: In video, the standard conventions used to specify the shape and size of the picture, and the amplitudes and arrangements of the picture, sync, and blanking signals.
FPS: Frames per second
Frame: A frame is a complete video picture. In the 2:1 interlaced scanning format of the RS-170 and CCIR formats, a frame is made up of two separate fields of 262.5 or 312.5 lines interlaced at 60 or 50 Hz to form a complete frame which appears at 30 or 25 Hz. In video cameras with a progressive scan, each frame is scanned line by line and not interlaced; most are also presented at 30 and 25 Hz.
Frame buffer: In a digital image processor, the hardware in which the frame memory resides. The frame memory is a RAM that stores a full frame of the video picture signal.
Frame grabbing: The acquisition and storing of a single video frame into a frame buffer of a digital image processing computer.
Frequency: The number of times per second a repetitive signal undergoes a full cycle of vibration. Frequency units are hertz (Hz). For spatial frequency, the number of cycles of image brightness variation along a scan direction, generally expressed in lines per millimeter or line pairs per millimeter.
F-Stop: A term dating back to the mid 19th century, some people believe the "f." is an abbreviation for "finestra", the Italian word for window.
Gain: The ratio of output signal to input signal is expressed in amplification. In video, higher gain is expressed in a higher contrast ratio between the black and light areas of an image.
Gamma: The exponent of the function that relates the output signal to the input signal. A gamma of 1 indicates that the device has a linear transfer characteristic. Used to describe the transfer characteristic of video cameras and monitors.
Gamma compensation: A circuit that adjusts the gamma in a piece of video equipment. In a color monitor, the gamma is adjusted to about 2.2 to compensate for the lower gamma of the Vidicon tube: Without compensation, the RGB signals would become disproportionate, and the hue would shift as the scene changes brightness.
GCHQ: Global Component Headquarters GCHQ.NET http://www.gchq.net/" href="http://www.gchq.net/">http://www.gchq.net/
Gen I image intensifier: An image intensifier consisting of a multi-alkali photocathode and a phosphor. Either of the inverter or proximity focused design. See Image intensifier.
Gen II image intensifier: An image intensifier consisting of a multi-alkali photocathode, one or more microchannel plates and a phosphor screen. Either of the inverter or proximity focused design. See Image intensifier.
Gen III image intensifier: An image intensifier consisting of a GaAs photocathode, a microchannel plate and a phosphor screen. The GaAs photocathode has at least three times the quantum efficiency of a multi-alkali photocathode. See Image intensifier.
Genlock: A circuit used to synchronize an internal sync generator to an external composite video signal. The signal from the sync source (async generator, VTR, or a camera) is fed to the GENLOCK input of the camera or special effects generator so that two or more video signals can be synchronized and mixed.
GHz: Abbreviation for Gigahertz. Frequency of one billion cycles per second. 1 GHz = 1,000 MHz.
Gram: Measure of weight
Graphical User Interface: (GUI) Pronounced 'goo-ee', a software interface which uses intuitive graphical representations - such as icons, push buttons, scroll bars, etc. - to start a computer program and to issue commands while it is running. GUIs are often contrasted with older 'text-based' interfaces. Less user-friendly, the latter require commands to be issued from the computer's keys.
Gray level: Also Grey value. The brightness of pixels as related to a digitized video image; commonly expressed in integers ranging from 0 (Black) 255 (White) for an 8-bit digital signal.
Gray level histogram: In digital image processing, a histogram that depicts the number of pixels at each gray value. The histogram can be used to measure the areas that have given ranges of gray value or to adjust image contrast by histogram stretching or equalization.
Gray scale: The various shades of gray or luminance values in a video picture. An analog scale that goes from 0 (Black) to 10 (White). There are two versions: one is linear, the other is logarithmic.
Ground: In electricity; "Earth" "Negative"
(H) Horizontal: Short for 1-H period, the time interval between (the leading edges of) the successive Hisync pulses.
HCCD: High performance CCD.
H hold: (Horizontal hold): The control on a video monitor that varies the free-running frequency of the horizontal deflection oscillator. Allows adjustment of the horizontal scan rate to achieve proper H sync.
Hidden camera: a miniature CCD board camera with a pinhole lens. Usually secreted in consumer items or worn on the body. Requires video recording equipment and a power supply usually 12 VDC or 9V. Wireless video transmission is commonly used to transfer composite video to a remote video recording device.
Highlight: The region of a scene or video picture with maximum brightness.
Horizontal resolution: The number of black and white vertical lines that can just be detected at the center of the video picture, measured for a distance equal to the height of the picture, expressed as TVL/PH (TV lines per picture height).
Horizontal scan (H scan): A single horizontal line of a raster-scanned video signal. Occurs 525 times per frame in the NTSC format and 625 times per frame in the CCIR format. The odd and even H-scan lines alternate in successive fields and are interlaced in the two successive vertical scans that make up the frame.
Horizontal-sync pulse (H-sync pulse): The sync pulses that control the start of the horizontal scanning video.
Housings: CCTV Camera housings.
Hue: The dominant (or complementary) wavelengths of light that give rise to the sensation of color such as red, blue, yellow, and green. Black, gray, and white are colors, but not hues.
Humidity: Humidity is simply the moisture in the air. Relative Humidity is the amount of water contained in the air at any given temperature as compared to the maximum amount of moisture the air can hold at that temperature when saturated.
Hyper Had (Hyper HAD): A CCD sensor in which each pixel contains a lens to focus the light to the central-most sensitive part of the pixel.
Hypertext: Any electronically stored text that contains links to other documents. When selected, the link - or hotspot - retrieves and displays related information, enabling readers to structure an inquiry according to their own interests and knowledge level. Information on the World-Wide Web is in hypertext format.
Hz (hertz): Cycles per second. MHz (mega hertz) is a million cycles per second.
ICCD: Refers to an Intensified Charge Coupled Device. A low light level video pickup device consisting of an image intensifier,coupled to a CCD array. The coupling may be either optical of fiber optical.
IEEE (Institute of Electrical and Electronic Engineers): An organization that (together with EIA and IRE) has helped establish industrial standards for electrical and electronic equipment and signals to promote interchangeability. The IEEE publishes many journals and conference proceedings related to video engineering and image processing.
IEEE Scale: A scale that expresses the levels of voltages in a video signal according to IEEE standards and the recommendations of the TV Broadcasters and Manufacturers for Coordination of Video Levels. 140 IEEE units corresponds to the peak-to-peak amplitude of the composite video signal, including 100-unit-high picture and 40-unit-high sync signals. For a 1-V peak-to-peak video signal, the picture signal occupies 0.174~0.7V and the sync signal 0.286~0.3V.
Ikegami: Japanese Camera manufacturer that leads the industry in low light television cameras
Illuminance: Also Illumination. The density of luminous flux incident on a uniformly illuminated area, measured in foot-candles (lumens per square foot) or lux (lumens per square meter).
Image: An optically reproduced scene. In video, the image formed by a lens on the camera's imager is transformed into an electronic signal that gives rise to a corresponding picture on the monitor.
Image analysis: The use of digital computers to derive numerical information regarding selected image features, such as contour lengths, areas, shape, size distribution, etc.
Image averaging: A way of reducing snow and other random picture noise by averaging the pixel brightness in several successive video frames. Achieved with a digital image processor or by photographic integration.
Image convolution: In manipulating an image with a digital image processor, the substitution of the gray value of each pixel with another gray value that takes into account the gray values of the neighbouring pixels. The convolution mask, or kernel, used to calculate the influence of the neighbours, determines the degree to which the picture is sharpened or smoothed by the convolution process. Contrasts with point operation, where the gray value of each pixel is transformed without considering the neighbours.
Image enhancement: A procedure for manipulating the video signal to sharpen of otherwise improve the video picture.
Image histogram: Also Histogram. A graph that depicts the number pixels displaying (range of) gray value. Histograms can be used for manipulating look-up tables that control the image contrast, and for measuring the number of pixels (i.e., the areas) that have selected gray values.
Image intensifier: A light-in light-out vacuum tube device capable of amplifying low light images. The tube consists of a photocathode on the input and a phosphor on the output and sometimes a microchannel plate for increased gain characteristics. They are made in two different types: inverter and proximity focused. The inverter type electrostatically focuses and inverts the image inside the tube. The proximity focused type has all of the elements closely spaced, has no need for focus electrodes and is much more compact. See Gen I, Gen II, and Gen III Intensifier.
Image processing: Generally refers to digital or analog enhancement and geometric manipulation of the video signal. Contrasts with image analysis, which emphasizes the measurement of image parameters. See also Image analysis, Image enhancement.
Image segmentation: In digital image processing, the partitioning of the image into non-overlapping regions according to gray level, texture, etc.
Image Sensor: See CCD
Image thresholding: A procedure that eliminates shades of gray from regions of a video picture above or below particular gray levels, replacing them instead with solid white or black. Used in digital image processing; also in analog circuits to "key in" a second scene with special effects generator.
Impedance: The resistance to flow of an electrical current. The impedance of a circuit can vary with frequency, depending on the values and arrangements of its inductive and capacitative components. For a circuit to receive or transmit a signal with minimum loss, especially important in the RF range, the impedance's of its input and output circuits must match the impedance's of the devices, including cables, to which they are connected. See also Hi-Z, Seventy-five-ohm termination.
Infrared light: British astronomer Sir William Herschel discovered infrared radiation around 1800. He used a prism and a sensitive thermometer to detect "invisible" light found just below the red portion of the spectrum. The term infrared (meaning "below red") came into use because it describes where you find it on the electromagnetic frequency spectrum.
Infrared illuminators: A electronic device use to direct Infrared light (invisible light) that can be detected by the pickup tube of an intensified CCD Usually made of diodes arranged in sequence or halogen globes passed through special glass.
Infrared Lasers: During the years of 1975 to 1979 many scientists and institutions worked in the initial development of a family of gas lasers known as the "Excimer." Those pioneers and institutions included Charles Chase (Tachisto), Terry Mckee (Lumonics), Dirk Basting (Lambda Physik), J.J. Ewing, Ralph Burnham, Robert Sze, Richard Slater (Avco), Charles Rhodes, Paul Christensen, and others representing the United States Government Laboratories. All contributed significantly in the early development of Infrared Laser technology.
Instrumentation camera: The type of camera used in scientific and industrial imaging, as distinct from cameras that are designed for surveillance applications, as consumer products, or for studio and electronic news gathering.
Integration: The act of accumulating signal or charge on a video sensor such as a CCD. Usually done by inhibiting readout via electronic control of the scan.
Interface: In relation to human communication with a computer, the appearance of the screen via which the interaction occurs. Also: the boundary between two devices or programs in a transmission path. At an interface, the circuitry and/or software routine is standardized so as to allow information to pass from one device to the other. The interfaces themselves must be compatible for standardization to occur.
Interlace: The arrangement of the raster lines in standard video where the alternate (odd- and even- ) scan lines generated by the successive vertical sweeps fall in between each other. See also Non-interlace.
Interscene dynamic range: The greatest ratio of image contrast that may be achieved by a video detector by adjusting the gain, black level, and gamma for each occurring scene. From the lowest to the highest contrast images.
Intrascene dynamic range: The ratio of image contrast (black to white) that can be achieved by a video detector when set at a specific operating point. Unlike the dynamic range of the detector, which is greater since the camera can be adjusted for each specific operating point.
Inverter tube: See Image intensifier.
IRE scale: Now called the IEEE scale, since IRE (Institute of Radio Engineers) was absorbed by the IEEE. See IEEE scale
IRIS: The term comes from the human equivalent which is the part of the eye that controls the amount of light that enters the eye. In video it's an adjustable aperture built into a camera lens to permit control of the amount of light passing through the lens.
IRIS mode: Usually indicates which type of iris lens connection is made to the controlling camera, Either DC or Video or both. Most cameras are compatible with both types of lenses.
Jack (Audio): Use to connect audio input or output. Several different types available.
Jammer RF: Jams Radio frequency waves in a given area. Use to stop unwanted RF signals transmitting from or to a location.
Jitter: An instability of the video picture where the lines jump up and down for short distances (or appear to do so) at several hertz. Jitter may be seen on individual lines or on the entire picture. The jitter may be inherent in the video signal (e.g., in freeze frame when there is movement between fields), may arise out of misadjustment of the H and V HOLD controls, or may be caused by raising the monitor BRIGHTNESS and CONTRAST controls to high.
Jumpers: Function selectors for determining channel frequency on GCHQ Video Transmitters, Channel 1,2,3 or 4.
K: The small k is the SI standard for kilo, or one thousand. That's how the general public use it, and it is often used in computing in the same way: for instance with 'kHz'.
There is Mercury, Lead, and Electrolytic liquid in all Circuit boards inside LCD TV's. Do not Burn...
Best to turn into recycling center
CRT TV's have LEAD incased inside the screen. There is Mercury inside circuit boards
No faqs found in this category
Most TV's are now coming equipped with Fiber link audio connectors requiring a fiber out cable. The problem most people are running into is that the surround is RCA left and right.
The sollution is a "optical converer" It has a fiber to analog audio conversion allowing you to connect RCA cables to your surround ayatem.
Yes, You will need a HDMI splitter for your TV to get more than one HDMI input?
See our HDMI Accessories page!
Different solutions require different types of HDMI cables depending on the specific feature (or speed rating) you require for your application. The newest cable, "HDMI with Ethernet" (as defined in the version 1.4 test specification) is FULLY compatible with all previous HDMI cable versions.
Do I need "Ethernet HDMI"? For most home theatre and computer applications, the answer is "no". A small number of advanced 3D Blu-ray players and Home Theatre receivers are now finally providing support for HDMI v1.4 (aka "HDMI with Ethernet" or "HEC"), but still even FEWER devices are actually making use of this specific feature. Nearly all our current HDMI cable stock is now "HDMI with Ethernet". Any device needing an HDMI cable can use HDMI with Ethernet cable as it is fully backwards compatible. This cable feature allows your internet-ready entertainment devices, from gaming consoles to Blu-ray Disc players and more, to share an internet connection without any need for a separate Ethernet cable. Devices connected by the HDMI Ethernet Channel will be able to exchange digital content in its native format, enabling recording, storage, and playback options across a connected system, with no need for a separate Ethernet cable. The HDMI Ethernet Channel accommodates current and future IP-based networking solutions for consumer electronics, such as UPnP, LiquidHD, and DLNA. HDMI with Ethernet is the ideal one-cable solution for connecting devices in these advanced home-networking environments using network protocols TCP/IP, UPnP, DLNA, LiquidHD, and so forth.
Do I need "Audio Return Channel" or "ARC"? ARC was an added feature to the version 1.4 standard. A typical use for ARC allowed for the audio produced by a TV (attached using an off-air antena, for example) to be fed back to a receiver for in-bound processing. "Return" then refers to the audio stream being returned upstream to the A/V receiver using the same HDMI cable that is normally used from the receiver to "send" a video and audio signal to the TV. Previous to this feature being implemented, one would need a seperate audio cable (a legacy left and right RCA cable, or newer Toslink audio cable) that would then OUTPUT from the TV and feed back into the receiver. Back to the question then. Do you NEED this feature? This can be useful if you have an off-air antena attached to your TV to receive free TV channels, or if you have a TV that is supporting newer streamed media services (such as NetFlix, or Amazon Video On Demand). In order for this feature to work, your TV MUST support "HDMI ARC", your receiver must support "HDMI ARC", and you must have a newer HDMI cable made using the newer version 1.4 standards - or look for an HDMI cable advertised as "HDMI with Ethernet".
What is CL-2 and CL-3? CL-2 is an abbreviation for "Class 2" as it refers to the wiring code in the USA. Many states require low voltage cables to be "CL-2" rated in order for them to be installed inside the wall. A CL-2 rated cable has a slightly different outer insulation with a different fire rating. A CL-2 rated cable can also be used outside the wall. Class 3 is a rating for cables over 300 volts. As HDMI cables only have 5 volts, a 5 volt HDMI Class-2 cable actually meets Class-3 specifications - but will still be called and labeled a CLASS 2 cable.
What is AWG? AWG is an abbreviation for American Wire Gauge. The SMALLER the number, the thicker the copper wire. A 22 AWG HDMI cable is almost twice as thick as a 24 AWG. A copper wire's thickness for a longer length HDMI cable helps reduce the resistance. Longer HDMI cables tend to be made from thicker copper wire. Other factors - such as a silver tinned coating on copper wire add to a cables conductivity.
Do I need a STANDARD SPEED or HIGH SPEED HDMI Cable?Nearly ALL HDMI devices need only standard speed support. "Standard Speed" means that the cable can sustain data speeds of at least 4.92Gbps as tested by HDMI LLC. Some newer Blu-ray players, and nearly ALL 3D Blu-ray players need a HIGH SPEED HDMI cable. They sustain speeds of at least 10.2Gbps due to the higher volume of video and audio data it must transfer. Some of our HDMI cables have been lab-tested to reach speeds of up to 15.2Gbps. However, as of the v1.4A specification, cables are only certified and tested to meet either 4.92Gbps (standard speed), or 10.2Gbps (high speed). Think of a cable that can reach speeds of 15.2Gbps as an over-sized garden hose: As the faucet can only output a maximum amount of gallons per minute, putting an over-sized hose on the tap will not get the lawn any wetter! Some of our NEWER HDMI cables (our ELITE HDMI cable line, for example) can now reach tested speeds up to 20.7Gbps. Currently, there are no devices making use of such incredible bandwidth capabilties - however, devices in the future may start to call for this expanded bandwidth. Buying a cable with beyond 10.2Gbps can somewhat "future-proof" your purchase.
What is the difference between a DIRECT HDMI connection and a MULTI-SEGMENT HDMI? How does this affect my cable selection? A multi-segment HDMI cable connection uses MORE than one HDMI cable to connect from the original SOURCE equipment (such as a Blu-Ray Player) and a TV. Intermediate equipment - such as an A/V receiver, HDMI Switch, or HDMI Splitter may be placed in-between the source equipment and TV. When you use more than one HDMI cable to ultimately connect from the source equipment to the TV, a significant amount of added electrical resistence as added to the circuit compared to a "direct HDMI connection". A direct HDMI connection would use a single HDMI cable connected to the SOURCE equipment and be attached directly to the end TV. Let's look at the following two examples:
Why is a CERTIFIED HDMI Cable important? Only about half the vendors (store-fronts and websites) sell truly CERTIFIED HDMI cables. CERTIFIED means that cables have been tested by Silicon Images and HDMI LLC, and they meet or exceed testing specifications set out by a specific test version (such as 1.3B or 1.4A). ALL our HDMI cables, and HDMI related products are certified. We refuse to purchase cables or products that are not. Ask your store if they can produce the actual HDMI certification document. All our HDMI cables have this document available on-line or by request. Yes, there are CHEAPER HDMI cables for sale. Certification and an ISO quality process ensure you are getting a top quality product from My Cable Mart at a reasonable price. Don't be fooled by $1.00 cables on E-Bay!
»Encoding rate is about 5 times greater
(Better quality picture!)
•Aspect ratio is 16X9 vs. 4X3
(Wide screen view!)
•Audio is most often Dolby AC3
(Higher quality sound!)
»Encoding rate is about 5 times greater
(Better quality picture!)
•Aspect ratio is 16X9 vs. 4X3
(Wide screen view!)
•Audio is most often Dolby AC3
(Higher quality sound!)
(Better quality picture!)
•Aspect ratio is 16X9 vs. 4X3
(Wide screen view!)
•Audio is most often Dolby AC3
(Higher quality sound!)
Between 600-700deg optimal.
NOTE: The amount of TIME you deliver the heat will impact the rate at which the solder will flow and or be removed.
Other considerations are wheather an sensitive IC is nearby.
If there are solder conections on both sides of the board
Yes, We have roll around carts with TV stands that can accomodate upto a 70" LED TV,
We are open from Tues thru Friday by appointment and Saturday 10-5pm for all resedential TV repair walkin customers
Yes, Look at our SERVICES drop down and select Electronic/TV repair policy.
Any size 12v solar panel will charge a car battery. The question is how long will it take? From a dead battery a rough estimate-
No, Sirrus/XM has to be mounted outside faceing the SW sky. XM/Sirrus transmits a scattered beam allowing the antnna to work in most enviroments outside.