Satellite TV service providers use multiple satellites to deliver their content - implying that multiple LNBs are required to receive all television programming supported by a satellite TV service provider.
LNB's use an antenna probe inside the feedhorn to pick up the signal focused by the satellite dish. The probe has to be aligned mechanically in a vertical or horizontal direction or left and right hand circular polarization for DBS satellites in line with the polarization of the signal transmitted by the satellite transponders.
This dual polarization is used by satellites to avoid interference between adjacent channels, and is achieved by assigning even and odd transponders on the satellite, different polarization. LNBF's employ a dual antenna probe setup inside the throat of the feedhorn with one aligned vertically and the other horizontally or left and right.
Switching to the correct polarized probe is carried out electronically via a voltage sent up the coaxial cable by the receiver. Feedhorn Installation Tips Proper installation and adjustment of the feedhorn is critical to system performance. It is particularly important if you are installing a feedhorn that receives Ku-Band signals.
In order to find the correct focal distance for tracking, the feedhorn must be at the correct distance from the center of the dish, properly oriented, centered and perpendicular to the plane of the antenna.
The polar axis is a line that runs through the center of the dish pivot points. It is the axis around which the dish will rotate. Another way to look at it is If your dish is positioned so that it is pointing at it's highest point of travel the zenith of the arc Proper orientation in these terms means that you point the arrow of the polar axis template at 12 o'clock directly in line with the axis.
If you do not have a template, you can get close by siting down the long side of the servo motor; pointing it at about 11 o'clock. This can be done by measuring from the feedhorn to at least 3 different points around the rim of the dish i. The 3 measurements should be equal.
Use the adjustments in the feed support legs or guy wires if you have a buttonhook support to make any necessary adjustments. The easiest way to check this is to use an inclinometer or universal protractor. Check the angle at the center of the dish and across the throat of the feedhorn; the measurements should be the same. When dealing with most prime focus antennas, the number should come out between. If you notice, most of those numbers are also on scale on the side of the feedhorn.
What this adjustment actually does is determines how wide of an angle the feedhorn can "see". If the dish is very deep example: 10ft diameter dish that is 24 in. When that is the case, the focal distance is often only a few inches greater than the depth of the dish.
Therefore, the feed needs to be able to "see" nearly straight to the side of the opening in the throat. Conversely, if the dish is very shallow example: 10ft diameter dish that is 11 in. In that case, the feed would need to have an narrower field of view so it would "see" the whole dish, yet not see past the edge of the dish.
Measurements should be in like units you can't use feet for the diameter and inches for depth. For the example, we will say we have a dish that is inches in diameter D and 18 inches deep d. They are usually indicated by the fact that every other channel is bad. You will notice that on some satellites, only the even numbered channels will come in, while on other satellites only the odd numbered channels will come in. This happens because the probe inside the feedhorn will not turn the 90 degrees that is required to change from a horizontally polarized channel to a vertically polarized channel.
If your satellite system is several years old, the problem is most likely that the servo motor that drives the probe has failed. Here are some steps to take to find the problem: 1 - Use a volt meter to check the voltage at the back of your receiver to make sure that the voltage is coming out of your receiver.
The pulse output is what tells the servo motor how far to turn the probe. You will read from. Then, go out to the dish and remove the feedhorn cover. Disconnect the 3 wires that are connected to the servo motor. If you are NOT getting the same voltage as you had at the receiver, then you have a wiring problem.
If you are getting the same voltage, reconnect the 3 wires, proceed to step 4. If you hear the servo motor turning, but there is no apparent change in the position of the probe remove the throat cover and look inside the throat to see the probe , remove the servo motor and pull up gently on the amber colored drive shaft that couples to the servo motor.
If the shaft pulls out, you will need to send the entire feed to repair. You can usually purchase a servo motor at any satellite dealer. If you find that the servo motor seems to be buzzing all of the time or if you are watching a program that seems to fade out intermittently and will come back by itself or if you change the channel up or down and back, the problem is also likely to be a bad servo motor. But try these steps to determine if the problem is more serious: 1 - Take the servo motor off of the feedhorn and hook it up directly to the back of your receiver.
You must disconnect the wires going to the dish for this test to be valid. If it turns when you change channels and does not drift or buzz when you are not changing channels, that tells you that the receiver and servo motor are working properly and the problem is likely to be noise being pick up by your unshielded pulse line.
The only way to correct this problem is to make sure that the pulse line is shielded and the shield is grounded at one end. You need to replace it. We hope this information was helpful. If you can't solve your polarity problem after following the instructions and tips above, we recommend calling out your local satellite dealer to troubleshoot the system further. Dishes range in size from inch to inch x inch. However, more than the shape or size, the real significant difference between the various types of dishes relates to the number of LNBs, and the number of supported outputs.
Typical satellite dishes can vary from the simple inch dish with a single dual LNB this is a two LNB configuration affixed at a small offset angle in a single housing , to five LNBs and four outputs, with each of these LNBs pointing to a different satellite orbit.
The number of outputs on the dish determines the number of digital satellite receivers that can be connected to that dish to watch different programs on different TVs simultaneously; in this respect, a quad output dish supports up to four different receivers. If you want to hook up more receivers than your dish can accommodate, you will have to use a multi-switch to split up the satellite feed without compromising signal quality.
Some multi-switches allow you to add over-the-air broadcasts or cable feeds, and send both signals to each viewing area via a single coax cable. In this case, you will need a diplexer for each viewing area to split up the signals again. As indicated earlier on, broadcast signals from satellites are split in two different polarizations, and these are differentiated at the LNB. If signals with different polarization were sent over the cable at the same time, they would interfere with each other.
A multi-switch works by taking the input from a dual LNB on the dish and then locks one of the LNB's to always look at the even transponders while the other LNB to always look at the odd transponders on the satellite. The switch then has multiple outputs to receivers. A receiver connected to a multi-switch sends a switching signal back up the coax cable to enable the switch to select the correct LNB it needs to look at.
In the case of multiple 'dual LNBs', the process is the same except that now, each of the LNBs will be looking at a different satellite. If you don't remember when your dish was installed or if you're just not sure that it is a 5-LNB, take a look at your dish and see if it matches either one of the DirecTV satellite dish. If not, you will have to order a new dish. With the slightly smaller inch, you can only pick either one of these satellite slots.
To receive all available DISH Network channels, including all high definition local and national channels from a single satellite dish, you need an MPEG-4 compatible dish antenna.
Note: Deciding on the required number of LNBs, shape and size of your satellite dish, depends on a number of factors, including the area where you live, service provider, and programming package selected.
This is something that is best decided after you speak with your digital satellite TV service provider. Dish Installation Process Now that you have made the plunge and purchased a satellite dish, you need to get that satellite TV antenna up so you can receive all the channels!
The relatively small size of present day digital satellite TV dish antenna systems means that these may be practically fixed just about anywhere. In particular, these compact satellite dishes are especially suitable for city dwellers.
While you may choose to have your new satellite dish installed by a professional, yet the actual installation process is not difficult to do.
The only real difficulty that may arise in the process is when aiming the dish to get the best signal from the satellites. All rights reserved. This image may not be used by other entities without the express written consent of wikiHow, Inc.
Select a flat spot on or around your home. Find a level place that is accessible if you need to clean off or adjust the satellite dish later. If you have space, the safest place for a satellite dish is on the ground. It will have plenty of room to point north or south, depending on where you live. Also, keep the dish away from falling snow or ice, such as from your roof or nearby trees. Try to find a spot close to them to make the wiring process easier.
If you mount the dish on the ground, you will need to dig a trench to run its cables to your home safely. Check for any obstructions blocking the dish's view of the sky. Stand where you plan on installing the dish. Look up to the sky. If you see buildings, trees, or even clotheslines in the way, then find another spot. These obstacles stop the dish from receiving a clear signal, affecting your picture quality. The rod gives the dish more height without it needing to be on the roof.
Satellite dish installers almost automatically go for the roof to guarantee the satellite isn't obstructed. You may need to do this, too, if you can't find an exact spot elsewhere. If you're in the northern hemisphere, the dish needs to point south to receive a signal. If you're in the southern hemisphere, it needs to point north, so keep that in mind when looking for obstacles.
Hold the dish's mount to your home and mark the screw positions. The dish's support is an L-shaped rod with a base plate that fastens to your home. Position the base plate flat against the wall or roof in the location you chose. Look for a series of holes on the plate for bolts. Then, use a permanent marker to note the position of these holes on the roof. Don't try to anchor it to siding since it won't hold. Calculate the size of the pilot holes needed to secure the mount. The holes' exact size and depth depend on the dish you're installing, so reference the components that came with the satellite.
That number will tell you how wide the holes need to be. Create the pilot holes using a drill bit the same size as the mounting bolts. Use a masonry drill bit to break through stone and other rigid surfaces without damaging your drill. The bit needs to create holes that are the perfect size for the bolts. Drill into the spots you marked earlier once you are ready. Make sure the holes you create are straight, so the mounting bolts fit properly. If they are too small, the bolts won't fit.
Erring on the side of caution is better when drilling. You can always widen a small hole. Place the mount's metal plugs into the holes you drilled. Your dish will come with a set of metal plugs that serve as wall anchors. One end of each plug will have a bolt hole in it. Flip the plugs, so the openings face toward you rather than the wall.
You need those openings to secure the mount. When you bolt the wall mount in place, the tails open up, making the plugs harder to remove.
Secure the plugs into the wall with a hammer and chisel. Place the tip of a chisel against one of the bolts. Give the chisel's handle a couple of good whacks to push the bolt into the wall. Keep hammering until the bolt is flush with the wall. Then, repeat this with the remaining bolts. Make sure the bolts are level with the wall, or else the dish's mount won't anchor properly.
Place the metal plugs and hammer them into the wall. Your dish will come with a set of plugs that serve as wall anchors. Position them, so their open end faces out from the wall. That opening is for bolting the wall mount in place. After pushing the plugs into the holes, tap them in with a hammer and chisel. They are what anchors the mount to the wall or ceiling.
If they are loose, your dish could end up crashing to the ground! Bolt the mount onto the plugs in the wall. Position the mount back on the wall, lining up the plate's holes with the pilot holes you drilled. Fasten the bolts by using a cordless screwdriver. Make sure the mount feels secure in the wall before you move on. If you're sure they are in correctly, take them out and recheck the plugs.
Cap each bolt with a metal washer and locking nut. These components prevent the bolts from coming back out of the wall. Slide the washers on first, which are flat metal disks that help the nuts work properly. Then, add the nuts and turn them clockwise with a wrench until they feel tight and no longer move. Be careful not to overtighten the nuts. Stop twisting them when they become hard to move. As long as they are not loose, the mount will also stay in place.
Part 2. Attach the antenna bracket to the low noise block LNB arm. Your dish will most likely come with a flat metal plate to connect the satellite dish to the L-shaped LNB arm and other components. Position the plate, so the prongs are on the left and right, facing you. Hold the LNB arm between the prongs with the tail end extending out past the plate's opposite side. The exact installation process, including the bolts' size, may vary a little depending on the dish you have. Refer to the owner's manual for more specific instructions.
Clip the antenna adjustment panel over the plate's prongs. The panel will look like a square box with one end open. Add a washer and nut on the end of each bolt after tightening them. This slot is what you use to point the satellite up or down. Fit the U-shaped rod inside the adjustment panel. Your dish will have a bent metal rod that fits into one of the slots on the adjustment panel. Slip the rod inside, sliding its prongs through the holes. Ensure the prongs point toward you rather than the tail end of the LNB rod you connected earlier.
Fit a small clamp over it, followed by a washer and nut on each prong. The adjustment panel has 3 different slots. Use the slots to reposition the satellite dish. In most cases, the middle slot is best for setting the dish at the proper angle.
Bolt the antenna bracket to the back of the satellite dish. You have a couple more bolts to add to finish the bulk of the assembly, and this is one of the easiest parts to finish. Line up the holes on the plate with the holes on the back of the dish. Stick the longest bolts you have, usually 2 to 3 in 5. Then, place a washer and nut on the end of each bolt, tightening it with your wrench.
If they feel shaky, carefully separate them and tighten the bolts. One last component, the LNB, controls the dish's functionality. First, slide the handle of the LNB onto the open end of the arm. Secure it with nuts and bolts, then take the LNB out of the box.
It looks almost like a round speaker or flashlight. Position it on the handle, facing it toward the dish before bolting it in place. You may need to loosen the LNB later to readjust it and improve the signal quality.
Connect the adjustment panel on the dish to the wall mount. Fit the dish onto the open end of the support. If everything is attached correctly, it will fit inside or behind the adjustment panel. You can then add the 1 or 2 remaining bolts to fasten these pieces together.
If the dish looks good, then you're ready to position it to communicate with a satellite. If the mount is meant to attach to the back of the panel, your satellite will also come with a pair of clips. Position them behind the support, then add the screws through them to bind the parts together.
Part 3. Select a satellite you wish to connect to. Pick a satellite that is in range of your particular dish. There are numerous satellites out there, but dishes cannot get signals from all of them.
If you bought your dish from a TV service, for instance, you might have a hard time connecting to their competitor's satellites. Tracking sites list the names, which usually include the owning company or the service they provide. If you bought a satellite service, it is possible to receive satellite signals outside that service.
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