Multi LNBFs and Receivers Setup

Connecting multiple dishes to one or more receivers is possible.  Below you will find some examples and drawing of how to achieve your purpose.  If you have any questions, don't hesitate to post your inquiry on our tech support forums.

What is DiSEqC? DiSEqC is an open standard that stands for Digital Satellite Equipment Control. Why DiSEqC? In order to squeeze more channels into a given frequency band width, channels are transmitted with vertical OR horizontal polarization. The conventional LNB known as the "Marconi (polarization) Switching LNB" responds to the supply voltage to change the polarization. If the supply voltage going up the dish cable is less than 15 volts, the LNB will "see" only vertically polarized transmissions. If the voltage is more than 15 volts, it will "see" only horizontally polarized transmissions. The older type of LNB had a separate polarizer to do this job and was able to use the voltage to select High Band or Low Band operation (by changing the internal oscillator frequency). So the modern LNB has a problem if it has to switch between two frequency bands. The problem was overcome with the introduction of the "Universal" LNB. The "Universal" LNB switches polarization with voltage but it also switches its internal oscillator for "High Band" when it "hears" a 22kHz tone. Specifically, the oscillator changes from 9.75 GHz to 10.6 GHz. Recently manufactured receivers incorporate a 22kHz tone generator which is menu-selectable on a per-channel basis. The tone comes on automatically if you program a channel for a higher frequency. Older receivers require an external tone generator box in order to make the "Universal" LNB select High Band. The external box can be controlled by a manually operated switch or by some feature of the receiver which will put a voltage onto its control wire to switch it on. An alternative use for the 22kHz tone is to control an external switching box which feeds signals from one of a pair of LNBs into the receiver. For example, you could have two separate LNBs on a dish connected to a switching box which is itself connected to the receiver by a single coaxial cable. When the box "hears" a 22kHz tone it swaps to the other LNB. DiSEqC is an extension of this idea. It relies on a switching box which detects the 22kHz tone pulsing rapidly on and off. In this way, a specially designed receiver can control numerous LNBs through a DiSEqC switching box. How DiSEqC Works DiSEqC messages are sent as sequences of short bursts of 22KHz tone modulated on the LNB power supply carried by the coax cable from the LNB input on the receiver (the master). Messages comprise a number of digital bytes of eight bits each. Each bit occupies a specific time and the proportion of that time filled with the 22KHz burst determines whether that bit is a 1 or a 0. The first byte is the Framing byte. The first five bits in this follow the pattern, '11100' to allow listening devices (slaves) to synchronies to the signal. Some of these may change with later versions of DiSEqC. The sixth bit is set to 0 if the message is a command from the master or 1 if it's a reply from a slave. Bit seven is set to '1' if a response is required or 0 if not. The last framing bit signals whether this message is a re-transmission of a message for which a reply has not been received. The second byte indicates which family of devices the message is for. The first half (four bits) indicates the type of device (LNB, switch, positioner etc) and the second half the particular type. In each half of this Address byte a value of 0 means the message is open to all. Next comes the Command byte. This actually tells the listening devices what to do. This is followed by a number of Data bytes to pass on numbers relevant to the command (such as the angle required from a separate polarizer). For control of simple mini-DiSEqC switches, one of two tone bursts, generated with a sequence of nine DiSEqC '1' bits and a 12.5ms burst of 'raw' 22KHz tone. DiSEqC applications DiSEqC system has been designed primarily to meet the problem of two-satellite, two-band systems with ease. It has dedicated outputs to select polarity, satellite position and frequency band. The option output can be used along with the satellite position output to select up to 4 LNBs on a multi-feed system.

the Satellite System Grounding the satellite system to the central building ground helps protect it and other components from lightning damage. Different brands of satellite systems may have special grounding requirements. However, dish installation should comply with local codes and the National Electrical Code (NEC). Refer to your satellite system’s user guides for any other additional grounding information. Grounding the satellite system is something you can probably do yourself. But if you’re not sure, you should contact a qualified electrician. Acceptable central building ground points  • Grounded interior metal cold water pipe within five feet of the point where it enters the building. • Grounded metallic service raceway. • Grounded electrical service equipment enclosure. • Eight-foot grounding rod driven into the ground (only if bonded to the central building ground by #6 or heavier bonding wire). You can buy a grounding rod at Home Depot or Lowes. • Other acceptable grounding electrodes that comply with sections 250 and 810 of the National Electrical Code (NEC) IMPORTANT Routing and Grounding the Cables 1. Attach the grouding block  to the side of your house close to the point you have chosen as the coaxial cable entry point. You may have to use anchors, togglers, or wood screws depending on the surface on which you are mounting the grounding block.  Step 1: CAUTION:  It is extremely important to ground the dish AND the coaxial cables to a single point in the central building ground. A nearby lightning strike can easily damage an ungrounded dish, the receiver and your TV. Connecting both ground wires to the same point in the central building ground meets code requirements and provides the best protection for your equipment. Attach the grounding block to side of your house at your designated entry point.: The United States National Electrical Code specifies that coaxial cable that is exposed to lightning shall be connected to the grounding system of the building as close to the point of cable entry as possible. 2. Route the coaxial cable and messenger (ground) wire from the bottom of the mast to the grounding block.  3. Make a 3"- 5" drip loop using cable clips at the grounding block. This will prevent water from running into the connection at the grounding block. 4. Place some silicone grease on the connector and connect the coaxial cable to the grounding block 5. Secure the messenger ground wire the grounding block.  6. Locate the central building ground. 7. Use a grounding wire (#10 copper or #8 aluminum) that will extend from the grounding block to the central building ground. Attach the grounding wire to the grounding block by placing it through the wire hole in the grounding block and tightening the screw. 8. Route the grounding wire from the grounding block to the central building ground, and connect to the central building ground. Cable Routing Tips • If you are routing the • If you are routing the wire or cable above the ground, use cable clips to secure the two to a wall or surface. grounding wire in an area where people or animals are not likely to come in contact with the cable. • Whether you live in the city or the country, Make sure you route the grounding wire along the ground, make sure the wire is buried deep enough so that it will not be damaged or uncovered.