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|  Television tuners and demodulators. Products for CATV, UHF & VHF. Channels 1 through 125. Book mark us now, press Ctrl and D at the same time. |
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This item is no longer avalable.
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Not a Descrambler Receives CATV, channels 1 through 125, also VHF & UHF channels 2 through 69. 54 through 806 MHz, Audio and Video Outputs. Includes a built-in channel 3 or 4 modulator. Volume control, antenna or cable input. Infrared remote control. MODEL # PRICE 8155 VIDEO TUNER 120 VAC |
Rear
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Below is an all text version.
| INTRODUCTION: 8155, VOLUME-CONTROL CATV CONVERTER, effectively receives both broadcast TV and CABLE TV signals of VHF/UHF/CATV from 54 to 806 MHz. After separating process. 8155 provides outputs of Audio signal, Video signal, and channel 3 or 4 TV signal to offer user an excellent enjoyment of TV set and monitor. A. MAIN FEATURES & FUNCTIONS: 1. Infrared remote control. 2. Digit-displayed channel number. 3. Digit-displayed volume. 4. VHF/UHF/CATV full bandwidth 54 to 806 MHz. 5. RF output channel 3 or 4 switchable. 6. Inner-set channel quality:181. 7. Offer user free selection of memory for 181 channels. 8. Three channel selecting methods: By CHANNEL up-down keys. By CHANNEL MR key. Key in the desired channel number 9. May control TV switching from 8155. 10. Offer sleep timer: 0,15,30,45,60,75,90 minutes, and the rest time viewing function. 11. Input power 120 V 60 HZ Power consumption: 16 W maximum. Output power AC 120 V, 500 W maximum. 12. Channel-Frequency chart as attached. B. REMOTE CONTROL BUTTONS & OPERATIONS: POWER:(common to both the converter and the remote control). Press once to turn on and again to turn off. If your TV is plugged into the converter: it should turn on in conjunction with the converter. SLEEP: Depress the sleep button, each time will increase 15 minutes. To deactivate the sleep timer depress the sleep button till 0 is shown. After sleep time setting and some minutes later, depress the same button to check the rest time. Depress the button again prior to the display changing in case you like to increase the time. 0-9: Depress the 2 digit number to go to the channel desired. Channel up: Press to scan to the next highest channel. CHANNEL down: Press to scan to the next lowest channel. LCR: Last Channel Recall for viewing the previous channel Push again to go to the new channel just viewed. MEM: General memory guide key. Press to store and again to delete. a. A dot will light when you finish a storing action. b. Apply to often viewed channels. MR: To recall channel from memory. F+: Depress to tune up frequency. Hold it in the freq. will be 3.5 MHz up. F-: Depress to tune down frequency. Hold it in the the freq. will be 3.5 MHz down. ><:Center Fine Tune is used to tune back to the original channel. VOL: To tune volume upward. VOL-: To tune volume downward. MUTE: Depress once to mute, again to recover. ANT: To switch between ANT & CATV. CATV: It is at ANT when the unit is just turned on. Depress the key to switch to CATV Band One small dot in display will be on to express it is at CATV. Notes: a. You can view 88 CHANNEL broadcast programs when the converter is turned on. b. Depress ANT/CATV button, then you can view 99 CATV programs. C. PRECAUTIONS: 1. Never push objects of any kind into this unit through openings as that could result in a fire or electric shock. Never spill liquid of any kind on the unit. 2. Refer all servicing to qualified personnel as opening or removing cover may expose you to dangerous voltage. 3. Unplug this unit from the wall outlet when any object/liquid gets into the unit. 4. Unplug this unit from the wall outlet when the unit is not in use for an extended period of time. D. LOCATION OF CONVERTER CONTROL: VOLUME DOWN -VOLUME UP - CHANNEL DOWN - CHANNEL UP. HRC/IRC/STD switch, located on the bottom of CATV Converter. In USA, most systems set in STD, while some systems use HRC/IRC. This information can be got from CATV Company. If you are unable to get the information, please set the switch at STD. If the picture is not good enough even after fine tuning, please try HRC. If it's still not acceptable, then try IRC. The wrong position on this switch will cause: (a) Basic stations are grainy, snowy, the picture quality is very poor. (b) All stations come in except CHANNEL 5 & 6. (c) Only CHANNEL 5 & 6 come in. E. INSTALLATION: 1. Place the Converter unit on/around your TV set, to make its infrared and display windows visible without any obstacle. 2. Pre-adjust on TV set for receiving channel. In case your TV set is plugged in the Converter, both TV set and the Converter will be activated by depressing "POWER" key on either the remote control or the converter. As the unit is just turned on, the display will show " " then you may adjust TV set. For instance, there is program showing in CHANNEL:7, operate CHANNEL ^ keys to make channel number to show " ", then go tuning your TV set to get the best picture to finish pre-adjust work. 3. Make connections as the following figure. F. REMOTE CONTROL: 1. Battery: 1.5V AA size, X2. 2. Remote control distance: Within 8.5 Point the remote control to the converter. |
| Adjacent Channels Any of two TV channels are considered adjacent when their frequencies are next to each other in frequency or channel number. Amplifier A device that boosts the strength of a television signal. Analog A method of signal transmission in which information is relayed by continuously altering the wave form of the electromagnetic current. Now used in AM radio or most voice telephone circuits. In telephone transmission, the signal being transmitted voice, video or image is "analogous" to the original signal. Antenna A wireless system component that converts wired electrical energy to wireless radio waves, and directs them through the air in some pattern. Antenna Array An antenna comprising a number of radiating elements, generally similar, which are arranged and excited to obtain directional radiation patterns. Attenuation In general terms, a reduction in signal strength. Automatic Frequency An arrangement whereby the frequency of an oscillator is automatically maintained within specified limits. Automatic Gain Control A circuit for automatically controlling amplifier gain in order to maintain a constant output voltage with a varying input voltage within a predetermined range of input-to-output variation. A process by which gain is automatically adjusted as a function of input or other specified parameter. Axial Ratio The ratio of the axes of the polarization ellipse. Backhaul Point-to-point video transmission from a remote site back to a central site for further distribution. Band A clearly defined range of radio frequencies dedicated to a particular purpose. Bandwidth The number of cycles per second (Hertz) expressing the difference between the lower and upper limiting frequencies of a frequency band; also, the width of a band of frequencies. The range of frequencies within which the performance of the antenna, with respect to some characteristic, conforms to a specified standard. Greater bandwidth generally provides for a more robust system because changes in the installation environment will not degrade antenna performance. Bandwidth A range of frequencies on the electromagnetic spectrum. Beam width In a plane containing the direction of the maximum of a beam, the angle between the two directions in which the radiation intensity is one half the maximum value of the beam. Bi-directional Communications between two points where each point both transmits and receives. Bird Slang for communications satellite. Bounce Sudden variations in picture presentation (brightness, size, etc.,) independent of scene illumination. Broadband A descriptive term for evolving digital technologies that provide consumers a signal switched facility offering integrated access to voice, high-speed data service, video-on-demand services and interactive delivery services. Broadband In television system use, a device having a bandpass greater than the band of a single VHF television channel. CATV Cable TV A service through which subscribers pay to have local television stations and other programs brought into their homes from the antenna via coaxial cable C-Band The 3.7 - 4.2 GHz (Gigahertz) frequency band is used for the distribution of programming by virtually all satellite/cable networks. There are 22 C-Band satellites in operation over North America today. They range in power from 5-11 watts per transponder, requiring receive antennas of 5-12 feet in diameter. Beginning in 1992, the fleet was gradually replaced with higher powered (10-17 watt) satellites. This allows the average size of a C-Band installation to be reduced to 90 inches in diameter. Channel A 6 MHz wide portion of the RF spectrum carrying TV video and audio carriers. Clarke Belt The name given in honor of Arthur C. Clarke, to the orbit 22,300 miles directly above the equator where satellites can maintain a stationary position in relation to the earth. Also called geostationary orbit. Coax Short for coaxial cable.  Coaxial Antenna An antenna comprised of an extension to the inner conductor of a coaxial line and a radiating sleeve which in effect is formed by folding back the outer conductor of the coaxial line. Coaxial Cable A type of cable capable of transmitting a range of frequencies with low signal loss. Commonly used for transmitting video and audio in security systems. Coaxial Cable A type of cable commonly used in cable (CATV) and direct broadcast satellite (DBS) television systems. Composed of two concentric conductors (an inner wire and a braided shield) separated by a dielectric material. The whole thing is usually wrapped in another insulating layer and an outer protective layer. Most coaxial cable used in CATV and DBS applications has an impedance of 75 ohms. A coaxial cable has great capacity to carry great quantities of information. It is typically used to carry high-speed data and in CATV (multiplexed TV stations.) Compression A term used to denote reducing the amount of bandwidth needed to transmit video or audio, thus increasing the capacity of a satellite transponder. The reduction in gain at one level of a picture signal with respect to the gain at another level of the same signal. Crosstalk An undesired signal from a different channel interfering with the desired signal. dB Decibels A technique for expressing voltage, power, gain, loss, or frequency in logarithmic form against a reference. Typical references include volts, Watts or Ohms. An analog unit of measure of signal strength, volume or signal loss due to resistance as expressed in logarithmic form. A measure of the power ratio of two signals. In system use, a measure of the voltage ratio of two signals, provided they are measured across a common impedance. Hz. Decibels are calculated using the expression: dB = 10*log(x/y) dBi A ratio of decibels to an isotropic antenna that is commonly used to measure antenna gain. The greater the dBi value, the higher the gain and, as such, the more acute the angle of coverage. dBmV A signal measurement whereby 0 dBmV equals 1000 microvolts across 75 ohms. A recommended signal level for a TV to receive is 10 dBmV. DBS Direct Broadcast Satellite A high-powered satellite that transmits or retransmits signals which are intended for direct reception by the public. The signal is received by a small (typically 18-inch diameter) dish mounted on the sides of homes or on other buildings. Signal content is generally television programing. Decibel A unit to measure the relative levels of current, voltage or power. This is the scale used to measure the strength of a TV signal. An increase of 3 dB indicates a doubling of power. Demodulation The process for retrieving an information signal that has been modulated onto a carrier. Descrambler Set-top box. A device which corrects a signal (often video) that has been intentionally distorted to prevent unauthorized viewing. Used with satellite TV systems. Digital A method of storing, converting and sending data in the form of binary digits ( 0 or 1). In displays, the use of digits for direct readout. In telecommunications, in the recording or in computing, digital is the use of a binary code to represent information. Analog signals (like voice or music) are encoded digitally by sampling the voice or music analog signals many times a second and assigning a number to each sample. Recording or transmitting information digitally has two major benefits. The signal can be reproduced more precisely so digital transmission is much "cleaner" than analog transmission. The second major benefit of digital is that the electronic circuitry to handle digital is getting cheaper and more powerful. Digital Recording Technology that enables video images to be stored on a hard drive or other digital storage medium rather than on an analog medium such as a videotape. Dipole A type of low gain antenna consisting of two (often internal) elements. Directional Antenna An antenna having the property of radiating or receiving electromagnetic waves more effectively in some directions than others. Dish cover A cylindrical weather protection device. Dish Size Refers to the diameter of the dish, or antenna, used in satellite reception. Dish Slang term for antenna. Distortion The deviation of the received signal waveform from that of the original transmitted waveform. Distribution Amplifier A device that provides several isolated outputs from one looping or bridging input, and has a sufficiently high input impedance and input-to-output isolation to prevent loading of the input source. Diversity Antenna An intelligent system of two antennas that continually senses incoming radio signals and automatically selects the antenna best positioned to receive it. Downlink To receive from a satellite also, the dish used for reception. DSL Digital Subscriber Line A generic name for a family of evolving digital services to be provided by local telephone companies to their local subscribers. Such services go by different names and acronyms - ADSL (Asymmetric Digital Subscriber Line), HDSL (High Bit Rate Digital Subscriber line) and SDSL (Single Pair Symmetrical Services). Such services propose to give the subscriber up to eight million bits per second one way, downstream to the customer and somewhat fewer bits per second upstream to the phone company. DTH Direct-To-Home. A term referring to all home satellite platforms. DVR Digital Video Recorders (same as PVR). Dynamic Range The difference between the maximum acceptable signal level and the minimum acceptable signal level. Embedded Antenna Typically an antenna that is enclosed into a product's housing or case, or one that is not readily discernible by a casual observer. The antenna forms an integral, inseparable part of the product. Encryption/ Decryption Encryption is the process of electronically altering a video and/or audio from its original condition. Decryption is the process of returning the video and/or audio to its original condition. EPG Electronic Programming Guide. F-connector The final piece of hardware on a cable designed for CATV or DBS or other signal distribution applications. It is cylindrical with a center pin sticking out, that plugs into the set-top box, cable ready TV, satellite receiver, or VCR. Feedhorn The part of the satellite system that collects and focuses satellite signals reflected by the antenna. Fiber Optics Fiber A shortened way of saying "fiber optic." Fiber is made of very pure glass. Digital signals, in the form of modulated light, travel on strands of fiber for long distances. The big advantage that fiber has over copper is that it can carry far, far more information over much, much longer distances. Field of View The maximum angle of view that can be seen through a lens or optical instrument. Field One of the two equal but vertically separated parts into which a television frame is divided in an interlaced system of scanning. A period of 1/60 second separates each field start time. Filter A circuit that selects the frequency of desired channels through the use of band pass, low pass, and high pass filters remove certain unwanted signals to make room for the insertion of a new modulated TV channel Frequency Response The range of band of frequencies to which a unit of electronic equipment will offer essentially the same characteristics. Frequency The number of times an electromagnetic wave goes through a complete cycle in one second, measured in Hertz. FSS Fixed Satellite Service. Gain An increase in voltage or power, usually expressed in dB. In a given direction, 4 pi times the ratio of the radiation intensity in that direction to the net power accepted by the antenna from the connected transmitter. A measure of amplification expressed in dB. Gain of an amplifier is usually specified at the highest frequency of operation. Ghost A spurious image resulting from an echo. GHz Gigahertz; one trillion cycles per second (a measure of frequency). Ground Plane A conducting or reflecting plane functioning to image a radiating structure. GSO Geosynchronous Orbit; satellites in geosynchronous orbit travel around the earth in an area approximately 22,300 miles from the surface at the same rate that the earth turns, therefore completing one revolution every 24 hours. Headend A cable TV systems control center where incoming signals from satellites and other sources are put into the system. (Head End) The originating point of a signal in cable TV systems. At the head end, you'll often find large satellite receiving antennae. A central control device required within some LAN systems to provide such centralized functions as remodultaion, re-timing, message accountability, connection control, diagnostic control, and access. Headend Homerun Wire The Homerun Wire is most often a single wire (usually an RG6 or RG59 coaxial cable) that runs from each apartment building's meter room to each apartment and is designed to deliver television or telephone services. Some of the modern day Homerun Wires are being used to deliver all services, cable and satellite television, telephone and fax and high-speed Internet connections. High Definition Television Technology that significantly increases the resolution of digital video signals offering vastly improved picture quality over the current NTSC standard. Hum Electrical disturbance at the power supply frequency or harmonics thereof. Hybrid Satellite A satellite that carries two or more different communications payloads (i.e., C-Band and Ku-Band). Hz Hertz Cycle per second; a measure of electromagnetic frequency that represents the number of complete electrical waves in a second. One kilohertz (kHz) is one thousand cycles per second; one megahertz (MHz) is one million; one gigaHertz (GHz) is one billion. Impedance (input or output) The input or output characteristic of a system component that determines the type of transmission cable to be used. The cable used must have the same characteristic impedance as the component. Expressed in ohms. Video distribution has standardized on 75-ohm coaxial and 124-ohm balanced cable. Impulse Pay-Per-View Technology that allows the consumer to purchase a movie or special event instantly via a computerized order processing center. This technology allows for the processing of a high volume of orders in a short time period. Input Impedance The impedance presented by an antenna at its terminals. Inside Wiring That wiring located inside your premises or building. Inside wiring starts at the telephone or cable company's Demarcation Point and extends to the individual extensions. Traditionally, Inside Wiring was installed and owned by the installing company. Interference Extraneous energy which tends to interfere with the reception of the desired signals. IPG Interactive Programming Guide. IRD(integrated receiver decoder) A device capable of receiving and tuning satellite signals. The output of the receiver can be either Baseband video for use with video monitors or RF for use with standard TV sets. Isolation Amplifier An amplifier with input circuitry and output circuitry designed to eliminate the effects of changes made at either upon the other. Isolation Between Antennas A measure of power transfer from one antenna to another - the ratio of power input to one antenna to the power received by the other, usually expressed in decibels. Isotropic A hypothetical antenna having equal radiation intensity in all directions. Jitter Small, rapid variations in a waveform due to mechanical disturbances or to changes in the characteristic of components. Supply voltages, imperfect synchronizing signals, circuits, etc. kA-Band A higher frequency than Ku-Band, operating from 18 to 31 gigaHertz. kHz Kilohertz. Ku-Band The 11.7-12.7 GHz (Gigahertz) frequency band. This band has been split into 2 segments by the FCC. The first is the 11.7-12.2 GHz band known as FSS (Fixed Satellite Service) There are 22 FSS Ku-Band satellites in orbit over North America today. They range in power from 20-45 watts per transponder, requiring a 3-5 foot antenna for clear reception. The 12.2 - 12.7 GHz segment is known as BSS (Broadcast Satellite Service). Satellites in this band range in power from 100 - 200 watts per transponder, allowing the use of receive antennas as small as 12-18 inches. L-Band Potion of electromagnetic spectrum commonly used in satellite and microwave applications with frequencies in the 390 MHz to 1550 MHz range. The GPS (global positioning system) frequencies are in the L-Band. GPS uses 1227.6 MHz and 1575.42 MHz LEO Low Earth Orbit; satellites placed in orbit less than 22,300 miles above the earth. Light Electromagnetic radiation detectable by the eye, ranging in wavelength from about 400 to 750 nm. Line Amplifier An amplifier for audio or video signals that feeds a transmission line; also called program amplifier. Line of Sight An unobstructed straight line between two transmitting devices. Line of sight is typically required for long-range directional radio transmission. Due to the curvature of the earth, the line of sight for devices not mounted on towers is limited to 16 miles (26 km). LNB Low Noise Block convertor. System devise used to amplify and convert satellite signals into frequencies sent to the tuner. Loop Through Also called looping. The method of feeding a series of high impedance circuits (such as multiple monitor/displays in parallel) from a pulse or video source with a coax transmission line in such a manner that the line is bridged (with minimum length stubs) and that the last unit properly terminates the line in its characteristic impedance. This minimizes discontinuities or reflections on the transmission line. Loss A reduction in signal level or strength, usually expressed in dB. Power dissipation serving no useful purpose. Low-Frequency Distortion Distortion effects which occur at low frequencies. In television, generally considered as any frequency below the 15.75 kHz line frequency. Matrix Switcher A device that routes any of its inputs to any of its outputs. Inputs are normally cameras or alarms, and outputs are normally recorders or monitors. A matrix switcher allows a user to control what information is sent where within a large security network. MHz Megahertz, a measure of frequency in millions (mega) of cycles per second. MMDS Multipoint Multi-channel Distribution Service. MMDS is a way of distributing cable television signals, through microwave, from a single transmission point to multiple receiving points. Often used as an alternative to cable-bases cable TV. An MMDS service, "in digital form, will provide more than 100 channels to a radius of approximately 40 miles from the transmitter. The MMDS transmitter delivers video to homes that are in its 'line of sight.' MMDS transmissions are limited by the terrain and foliage of a given market. The microwave signal is received by an antenna on the subscriber's home, then sent down coaxial cable to a box atop the customer's TV set. The box decodes and decompresses the digital signal." MMDS is increasingly being called "Wireless Cable." Modems Acronym for Modulator/Demodulator. Conventional modems comprise equipment which converts digital signals to analog signals and vice versa. Conventional PC modems outputs data in the form of "1's" and "0's" which are represented by varying levels of voltage. The modem converts the digital data signal into variations of the analog sine wave so the data can be transmitted over the device with a digital bit stream. The modulation techniques include some combination of Amplitude Modulation (AM), Frequency Modulation (FM) and Phase Modulation (PM), also known as Phase Shift Keying (PSK). Used in combination, these techniques allow multiple bits to be represented with a single (or single set) OF SINE WAVES). In this fashion, compression is accomplished, which allows more data to be transmitted in the same period of time and which therefore reduces the connect time and the associated cost of the data transfer. Modulation The process of superimposing an information signal onto a carrier for transmission. The process where some characteristic of one signal is varied in accordance with another signal. The carrier may be modulated in three fundamental ways: by varying the amplitude, called amplitude modulation; by varying the frequency, called frequency modulation; by varying the phase, called phase modulation. The creation of a TV channel from a video and audio source for transmission over a distribution coaxial cable network. Modulator The electronic equipment required to combine video and audio signals and convert them to TV radio frequencies (RF) for distribution to other equipment (including televisions) on a cable network. MPEG Motion Pictures Experts Group. Multiplexer A device that can accept a number of camera inputs and almost simultaneously display them on a single monitor. Can be used to transmit multiple cameras over the same transmission medium. A device that accepts video signals from more than one camera and encodes them onto one signal that is sent to a digital recorder or VCR. The multiplexer also decodes the recording so it can play back video from one camera or several cameras at once on a monitor. NAB National Association of Broadcasters. NCTA National Cable Television Association. Noise The word "noise" originated in audio practice and refers to random spurts of electrical energy or interference. In some cases, it will produce a "salt-and-pepper" pattern over the televised picture. Heavy noise is sometimes referred to as "snow". NTSC Abbreviation for National Television Systems Committee. A committee that worked with the FCC in formulating standards for the present day United States color television system. A television industry group that develops standards for standard television broadcasting and receiving equipment in the US. Off-Air Reception of a TV signal that has been broadcast through the air by a TV station. Omni-directional Antenna An antenna having an essentially non-directional pattern in azimuth, and a directional pattern in elevation. Output The signal level at the output of an amplifier or other device. Packet Data A process where stored data is transmitted in discrete units, called packets, allowing for more efficient use of channel capacity and reliability of transfer. Patch Cords Cables used to interconnect electronic equipment often terminated with modular or RCA-type plugs. Patch Panel A panel where circuits are terminated and facilities provided for interconnecting between circuits by means of jacks and plugs. PCS Personal Communications System. Peak Pulse Amplitude The maximum absolute peak value of a pulse, excluding those portions considered to be unwanted, such as spikes. Peak-to-Peak The amplitude (voltage) difference between the most positive and the most negative excursions (peaks) of an electrical signal. A full video signal measures one volt peak to peak. Personal Video Recorder (PVR) Product that tracks viewing habits, records programs and has other interactive features such as pause and rewind. PIFA Planer Inverted F Antenna. Polarization In a given direction, the polarization of the wave radiated by the antenna. Alternatively, the polarization of a plane wave incident from the given direction which results in maximum available power at the antenna terminals. PVR Personal Video Recorder. A consumer device which uses a hard disk drive to record television programs based on the user's preferences. QPSK Quaternary Phase Shift Keying; a digital modulation scheme used in transmission communications that allows increased sending capacity Radiation Pattern (antenna pattern) A graphical representation of the radiation properties of the antenna as a function of space coordinates. Radome An enclosure for protecting an antenna from the harmful effects of its physical environment, generally intended to leave the electrical performance of the antenna unaffected. Resolution (horizontal) The amount of resolvable detail in the horizontal direction in a picture. It is usually expressed as the number of distinct vertical lines, alternately black and white, which can be seen in a distance equal to picture height. RF Radio Frequency The area (or band) of the electromagnetic spectrum where most radio communication takes place, typically from 100 KHz to 100 GHz. A frequency at which coherent electromagnetic radiation of energy is useful for communication purposes. Analog electrical signals sent on cable or over the air. Conventional (broadcast) television and radio, as well as cable TV, deliver RF signals to your television/radio. Ripple Amplitude variations in the output voltage of a power supply caused by insufficient filtering. Satellite Antenna (Dish) A parabolic antenna that collects satellite signals. C-Band antennas range in size from 5-12 feet in diameter; K-Band antennas range from 18 inches to 6 feet. Satellite Programmer A company that produces, packages or distributes video, audio, and/or data services for distribution to the home satellite dish and cable markets. SCPC Single Channel Per-Carrier; an economical way to get multiple signals on one transponder. Scrambling Altering a video signal transmission so it can not be received without an authorized operating decoder. Signal Leakage (Leakage) is a cable TV term. Leakage occurs when certain radio frequencies ooze out of the CATV's coaxial cable in such strength that they are evident outside the home. They might be sufficiently strong to interfere with aircraft navigation. Leakage is really a shielding problem. Smart Card Technology that allows for the upgrade of encryption security through the use of a consumer-installable card containing a new computerized security code. SMATV Dish & DBS Dish The dish-like antenna used to receive satellite signals. SMATV Satellite Master Antenna Television; or private cable; a miniature cable system that receives programming by one satellite dish and serves an entire housing complex, hotel or apartment etc. Splitter A passive device (one with no active electronic components) which distributes a television signal carried on a cable in two or more paths and sends it to a number of receivers simultaneously. Spread Spectrum A means of transmission in which encoded information is carried in discrete packages of information, then spread over a wide bandwidth for transmission to specific receivers that filter out the coded material. Stubby Antenna A short thick monopole. Sun Outage When the sun passes behind a satellite in relation to the earth and it‰s energy momentarily interferes with the satellite signals. This happens two times each year during spring and fall equinox. Superstation A local TV station whose signal is satellite delivered to cable systems and backyard antennas across the country. Switcher A simplified SEG that selects and mixes video signals from two or more sources. TDMA Time Division Multiple Access is one of several technologies used in digital wireless transmissions that increases the efficiency of the network by allowing a greater number of simultaneous transmissions. Networks using TDMA assign 6 time slots for each frequency channel. Devices using the wireless network send bursts of information that are reassembled at the receiving end. Terrestrial In communications parlance, this refers to earth, land or ground-based telecommunications systems. TNC (RP-TNC) A connector type unique to Net WORLD radios and antennas. Part 15.203 of the FCC rules covering spread-spectrum devices limits the types of antennas that may be used with transmission equipment. In compliance with this rule, Net WORLD, like all other wireless LAN providers, equips its radios and antennas with a unique connector to prevent attachment of non-approved antennas to radios. Transceiver A combination transmitter and receiver. Transients Signals which exist for a brief period of time prior to the attainment of a steady-state condition. These may include overshoots, damped sinusoidal waves, etc. Transponder A satellite component that receives and retransmits a TV signal or perhaps many narrower-band data or audio channels. TVRO (Television Receive-Only) An industry term used to describe a home satellite system that only receives and does not transmit satellite television signals. UHF Ultra High Frequency The part of the radio spectrum from 470 MHz to 806 MHz, including TV channels 14 through 83. Uplink To transmit to a satellite for relay; also, the dish used to transmit. Vertical Resolution The number of horizontal lines that can be seen in the reproduced image of a television pattern. VHF Very High Frequency. The part of the radio spectrum from 54 to 88 MHz and 174 to 216 MHz, which includes TV channels 2 through 13. Video Amplifier A wideband amplifier used for passing picture signals. Video Band The frequency band width utilized to transmit a composite video signal. Video Signal (Non-Composite) The picture signal. A signal containing visual information and horizontal and vertical blanking (see also Composite Video Signal) but not sync. Wireless Transmission A technology in which electronic devices send information to receivers using radio waves rather than wiring. Wireless A system without outside wires, for example cellular telephony or satellite television. Zapping Changing the channel by remote control during a program to avoid a commercial. Zipping Fast-forwarding through commercials when playing back a program on a VCR. |
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