Intro to Satellite Dish Cabling

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Satellite cable is typically called 'all-in-one' or 'direct burial (DBC)'. It is comprised of two RG-6 coaxial cables, a bundle of three color-coded 18, 20 or 22 gauge stranded wires for the feedhorn servo motor, and a bundle of five color-coded stranded wires for the actuator - two 12 or14 gauge for motor control and three 18, 20 or 22 gauge for sensor control. DBC cable is designed to be buried directly into the ground, without being run in conduit, though do not bury the cable until your system is completely connected and performing properly. Buy enough DBC to go up the pole of the dish and out to the center; it is best to make the wire one long piece as splices are a potential future trouble spot for corrosion and entrance for moisture into the system and a splice will also attentuate signal slightly.

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Remember, in wire gauge, the smaller the number then the larger the wire diameter.You will be able to run your system comfortably with 250 feet of cable and should not have a problem at 300 feet. Using a quality receiver receiving strong satellites the RG-6 coax will be 'ok' at 350 feet but it will be close to requiring an upgrade of all stranded wiring. For cable runs (distances) over 300 feet I would go for 12 gauge motor wires and then 20 or 18 gauge sensor wiring (whatever comes in the DBC bundle). If the DBC bundle contains the thicker motor and sensor wires and still contains RG-6 (which is 'ok') then use an in-line signal amplifier on the RG-6 LNB runs if you are encountering weak signals. Over distance, higher frequencies lose power/signal strength/definition, i.e. attenuate,.quicker than lower frequencies so it is conceivable the Ku line would need a line amp whereas the C line would not, all other things being equal. If in doubt, check with your cable supplier and equipment provider for their exact recommendations on length of cable run and size cable/wire to use.

Coax cable consists of an inner solid wire, conductor, which carries both the DC voltage to power the LNB and the signal from the LNB to the receiver, and the conductor is surrounded by a plastic or foam insulator (dielectric) and then covered with an outer 'grounding' foil sheath and then covered by an extra braided sheath and then the entire cable is coated by a durable outer plastic covering which is typically black, or pink if plenum fire retardant cable. The dielectric core establishes the impedance of the cable and serves as an insulator between the centr conductor and grounding sheathes; coaxial cable for satellite TV video is a 75 ohm impedance cable. To use RG-6 coax cable, an 'F' end connector (the same connector used for VCR connections) is attached to each end of the coaxial cable; it is a rather simple procedure which I have performed many times using a pair of pliers to crimp the connector to the cable rather than purchase a speciality coax 'F' connector crimp tool (of course no one recommends this). Be sure that the center conductor does not short out, i.e. touch, to the outer ground sheath as this will definitely kill signal passage and possibly blow the receiver's fuse and could conceiveably damage its internal power supply; just 'skin' back the sheath and clip it so that it can not contact the center conductor - a simple thing to do. If you are using RG-11 cabling be sure to get the 'F' connector for that size cable and even I recommend to use the proper coax crimping tool to install end connectors on RG-11 rather than use pliers. Also use a professional crimp tool when installing for commercial accounts and especially for your customers where plenum cable is employed. When end connectors are installed, pull on them by hand to ensure they are crimped well.

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For a single LNB feed, only one coax cable is used from the LNB to the receiver. For a dual LNB feed, i.e. no polarotor motor, a coax cable is run from each LNB to the appropriate connection at the back of the receiver - two coax cables are used. For a dual feed going to a single receiver the LNB connections are easy to install as the receiver will have two labeled LNB input coax ports - both a horizontal C-band port and a vertical C-band port. If each LNB output is to go to multiple receivers, i.e. a receiver by the TV in the main room and a receiver by the TV in a bedroom, then you will need to pass each LNB coax through a power passing splitter (in other words, you will need a power passing splitter for each LNB); be sure not to use a regular, in-house, low frequency splitter but a special splitter rated for the range of output frequencies of the LNB. A power passing splitter has dual purposes: to pass DC power (from the receiver) to operate the LNB through one port and to split the output received signal from the LNB for use with multiple receivers. The coax port that passes DC is to be connected to the receiver that controls movement of the dish. Don't forget to place a terminator on any unused splitter ports.

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Two cables are also used for a corotor feed. For a corotor feed going to a single receiver the LNB connections are easy to install as the receiver will have two labeled LNB input coax ports - both a C-band port and a Ku-band port (sample receiver wiring for corotor system). When a dual C/single Ku feed is used then three coax cables are required - the two with the DBC bundle and an extra coax run alongside the DBC bundle (sample receiver wiring for dual C, single Ku system). Two extra coax cables are required when a dual C/dual Ku feed is used for a total of four cables. Because receivers only have two input ports, if three or four coax inputs from the LNB to the receiver are used then you will need an electronic dual polarity satellite control switch for each LNB. It takes in both polarities, i.e. two coaxes, from each LNB then outputs a single coax to the back of the receiver with the polarity of the channel requested by the receiver (as you change channels you are in reality changing polarities and this switch coordinates that information to the LNB). Each set of horizontal and vertical LNBs will require this switch. The electronic switch is powered from the back of the receiver in accordance with receiver manufacturers instructions (see example combiner/control box for C-band LNB in this example receiver wiring for dual C, single Ku system). For receivers that do not have capability to power the switch, the switch can be purchased with an external DC power supply. NOTE: Control switch is placed in-line after the power passing splitter if more than one receiver is used - make a diagram of the coax paths from the LNBs to the receiver if you are slightly confused on the configuration of power passing splitters and control switches. Just remember, you will need a splitter port for each receiver and a control switch per receiver for each set of dual polarities brought down from the feed.

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One important thing to remember, no cable will forgive you if you put a staple or nail thru it!!, Also coax cable is not forgiving to being kinked so always loop roll coax and never bend it; and nothing kinks easier than RG-59. Damaged coax cable can detrimentally alter signal impedance and cause undue attenuation at certain frequencies (remember that channels are really nothing more than frequencies). I do not recommend using RG-59 cable for anything; it is the 'skinniest' cable available for video application and for some reason it is the favorite (because it is cheapest, I guess) of architects and construction managers to use to prewire a house. Besides kinking easiest and having a flimsy center conductor, RG-59 is a waste of money as it attenuates signal too quickly over any distance to be useful. Do not pay any attention to people that say RG-59 can be used for distances up to 100 feet - RG-59 is a waste of time to use; it kinks easier, has a flimsy center conductor (yes, I know you can purchase RG-59 with thicker center conductors but why bother when RG-6 is available) and it looses signal too quickly. NOTE: For all 'F' connectors - those for LNB connections, for insertions, for VCR connections - use the solid one-piece crimp style and not the two-piece style shown in the RG-59 photo above. A two piece connection is a definite aggravation.

In-line and distribution amps are sometimes required for long or undersized cable lengths. If you do have a problem with weak signal from the LNB to the receiver due to long coax distances, i.e. you arrive on a site and find it wired to the dish with undersized coax, such as RG-59, you can put an in-line UHF amplifier (900 -1750 MHz range) on the coax; it is powered by the center conductor of the coax (like the LNB) and typically comes in +10 and +20dB ratings and uses 'F' end connectors. If you are at the limit of RG-6 length, from receiver to dish, and should go to RG-11, you use an in-line amp. As a fact, if you stay under 200 feet on your RG-6 DBC, you will be fine with LNB signal and power to the sensor and actutor assemblies.
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If distribution wiring within the house is prewired with RG-59 (heaven forbid) then use the lower frequency (5-950 MHz) in-line amp on the coax - options include amps powered with an external DC power supply and by in-line DC (check your application and talk with your supplier to determine your need). If you are distributing signal to multiple TVs around a large house, you can use, for instance, a simple 25dB gain distribution amplifier which takes one combined line in and sends one combined line out. For use around a small to medium hotel or apartment complex, you can use an adjustable 60dB gain distribution amp which offers acceptance of combined or individual inputs and offers separate attenuation control for low band VHF, high band VHF and low band UHF. These type units are typically adjustable in 10dB input attenuation units and have individual output gain adjustments and offer front panel feature selectivity and control. NOTE: All frequencies given are for North American designations and products shown are typical examples of market availablity.

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