Information About ™Diplexer |
| CATEGORIES ABOUT DIPLEXER | |
| wireless communications | |
| broadcast engineering | |
| amateur radio | |
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Diplexers generally differ from '''Duplexers''' in that Diplexers are generally used to separate whole frequency ranges while '''Duplexers''' tend to separate small frequency differences. For example, a certain '''Diplexer''' may have two output ports, and one input port. Port A (Input), port B (Output 1) and port C (output port 2). Port A may be connected to a device that produces multiple frequency ranges, for example HF (High Frequency - Less than 30 MHz) and say VHF (Very High Frequency - 130 MHz - 174 MHz). The '''Diplexer''' might be used to separate these two "bands" (HF & VHF) into two different antennas. In our example port B may handle all frequencies below 50 MHz while port C handles those frequencies above 50 MHz. A Duplexer might have the same three ports as the Diplexer mentioned above, but would typically be used to separate frequency differences as small as 600 kHz. A three port diplexer is also known as a Triplexer. INDUSTRIAL Diplexing is extremely useful in reducing the number of to prevent Intermodulation and keep Reflected Power ( VSWR ) to a minimum for each Input transmitter and Frequency . While diplexers can combine a relatively wide Bandwidth , the major limitation comes with the antenna itself, which must be sufficiently Wideband to accept all of the Signal s being passed through it, and transfer them to the Air Efficient ly. One of the most massive diplexers in use is atop the Empire State Building in New York , where over a dozen Radio Station s transmit through one four- Panel Antenna . Diplexers are also used to combine the Audio and Video Carrier s for Television , and also for non- Broadcast applications such as Amateur Radio . Regardless of the actual application, the end purpose of the diplexer is still the same: to aggregate signals and reduce infrastructure. Another example of their use is in the TV broadcast industry in the electronic news gathering (ENG) vehicles (i.e. the "TV truck" you see when there's news going on). Diplexers are used to combine power, control & transmission signals from the inside of the truck, and send them up to the mast mounted RF equipment. By combining the signals onto one cable, the number of cables and conductors that must be run up the mast is reduced, conserving precious space in the conduit, and decreasing the weight load on the truck and mast. RESIDENTIAL Small diplexers are also used in the home, allowing Direct Broadcast Satellite TV signals from the Dish to the Receiver to Piggyback on one regular Coaxial Cable , along with lower-frequency signals from an outdoor Terrestrial TV antenna for local channels. This is extremely useful in homes which are already pre-wired, as it eliminates the need for the difficult installation of unsightly extra cables. However, the cables must be the higher-quality RG-6 , as the less-expensive RG-59 will not pass the high Intermediate Frequency (usually 950 to 1450 MHz) which the LNB outputs from the Feedhorn . In this case, one diplexer joins the two signals together. Another diplexer then separates the signals to the receiver of the TV set, and the IRD of the DBS set-top box. More complex systems have a distribution Amplifier , which allows each IRD to access multiple LNBs with different antenna Polarization s. These usually have an antenna input and a diplexer, so that the antenna signal is also distributed along with the satellite. Diplexers are also commonly used to combine UHF and VHF frequency signals (that is to say: TV and FM radio) onto one downlead which can then be split back into its component parts as required. SEE ALSO EXTERNAL LINKS |
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