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C-BAND FAQ the Beginning Part 2 of a 10 Part Series http://www.fta-n-more.net/forum/viewtopic.php?f=13&t=177	Page 1 of 1

Author:	Digi [ Fri Jun 04, 2010 6:02 am ]
Post subject:	C-BAND FAQ the Beginning Part 2 of a 10 Part Series
How do I get started assembling a home C-BAND satellite system? Part 2 About how much might it cost to put a system together? A home TVRO system once cost as much as $100,000 in 1980! Prices have dropped substantially since then, of course; a "typical" retail price home system (dish included) with professional installation could cost from $1500-$2500 depending on the setup. The good approach these days is to find a decent used system, as many of these are around; many people will actually thank you for "ridding them" of their "antiquated" TVRO system! TVRO systems are NOT antiquated, of course. Reasonably priced used systems can range from free to $250-$300 or so. Exactly what equipment do I need? There are six basic components to a big dish system: the satellite dish, the feed assembly, the low-noise block downconverter (LNB), the positioner/controller, the cable, and the receiver or IRD. The first component is the satellite dish. The satellite dish is unquestionably the most visible component of a home satellite system, and can range from five feet upwards to twelve feet or larger. The "average" size for a TVRO satellite dish is ten feet, but can be smaller in stronger signal areas. Most IRDs have a built in controller for moving the dish. Some receivers require an separate controller, sometimes called a dish mover, to control the position. Satellite dishes are also made of a variety of materials. Aluminum mesh dishes are the most common type, but solid aluminum and fiberglass dishes are not unusual. Each type has its advantages and disadvantages. Mesh dishes are usually less expensive than solid dishes, and easier to transport from the manufacturer and vendor to the installation site. Solid aluminum and fiberglass dishes generally have one primary advantage over mesh dishes. Although usually more expensive, solid dishes are usually better for overall reception quality, particularly with Ku-Band signals. Whatever type of satellite dish, a properly peaked antenna with a dish of the appropriate size should have no problem receiving both C-Band and Ku-Band signals. For locations subject to extreme weather, such as hurricane-force winds, extreme heat, or extremely heavy winter snow, Paraclipse made specially designed satellite dishes (the Classic series) ranging from 12 to 16 feet; these are quite pricey if you can find one, however, ranging from around $1000 to a whopping $7000 for the 16-footer! In terms of size, bigger is usually better for a TVRO system. Satellite signal strengths are almost always stronger in the center of the signal footprint, where an eight foot dish should have no problem receiving both C-Band and Ku-Band signals. The farther from the center of the footprint, the larger the size of the dish needs to be for quality C-Band reception. A twelve foot or larger dish may be needed in fringe areas such as Alaska, Maine, south Florida, Hawaii, and remote areas in Canada. For Ku-Band, size is much less critical and for Ku- Band only systems, a dish as small as 30 inches may work. However, it is usually not advantageous to have a Ku-Band only TVRO setup unless it is a fixed installation for reception of a specialty satellite, such as one with a large amount of international programming, for example. The second component is the feed assembly, which is where the real antenna is located. The feed assembly is used to "funnel" the satellite signal from the parabolic dish reflector to the antenna probe, which relays the signal to the LNB antenna for subsequent frequency conversion and amplification. The term feedhorn is often used interchangeably with feed assembly; this is not entirely accurate, as the feedhorn itself is just part of the overall feed assembly. The scalar ring is used for precision in focal point adjustment in conjunction with the dish reflector. Some feed assemblies are designed to mount two or more LNBs. Such feeds come in two basic types, those that mount one LNB each for each band, C and Ku, and those that mount one LNB for each polarity, vertical and horizontal for most satellites aimed at North America, or right hand and left hand circular for most of those aimed elsewhere. Hybrid types provide some combination of dual polarity and dual band. Multi LNB feeds usually have a separate antenna probe for each LNB. For dual band, polarity is controlled in the same manner as done for a standard single LNB feed, usually with a servo motor to mechanically move the antenna probe to match the desired polarity. Dual polarity feeds (orthomode) have no moving parts, and are used primarily in multi receiver installations to provide all receivers simultaneous access to channels on both polarities, something impossible with a servo actuated antenna probe. A disadvantage to using an orthomode feed is that, without the fine control of the servo motor, signals that deviate from true horizontal or vertical polarity cannot be optimally received unless the dish is fixed upon one satellite, and the feed assembly adjusted accordingly. Another type of feed, called an LNBF, is similar to that used on the little DBS dishes. An LNBF integrates feed, antenna, and LNB into a single electronically controlled unit. The third component is the low-noise block downconverter, or LNB. The LNB is the component that amplifies the very weak signal reaching the antenna from the satellite 22,247 miles above the equator, and converts the downlink frequencies to a lower block of frequencies more suitable for transmission through the cable to the receiver. The standard block of frequencies is 950-1450 MHz. Some early block downconversion systems used a 900-1400 or lower block of frequencies, and receivers designed specially for those frequencies. Older systems used separate components for signal amplification (low-noise amplifier, or LNA) and downconversion (block downconverter). Really old systems didn't downconvert a frequency block for transmission to the receiver, instead sending in only one specific frequency requested by the receiver. C-Band LNBs are rated in degrees Kelvin; Ku-Band LNBs are measured in decibels (dB) instead of degrees Kelvin. For C-Band LNBs, up to 30 degrees K is usually suggested, but this is simply to maximize picture quality. For C-band and a large dish reflector, anything up to 100 degrees is adequate for 99% of the video signals out there, and should give equal or better results to a sub 30 degree LNB on a smaller dish. Only for very weak signals is a sub 30 degree LNB important on C-band. For Ku-Band LNBs, a range up to around 1.5 dB should provide acceptable picture quality. Note that these numbers only apply to analog-only reception or larger dish reflectors; for quality digital reception or smaller dish reflectors, LNBs rated around 20 degrees K or lower for C-Band and 0.7 dB for Ku-Band should be optimal. Make sure that you do some research before buying LNBs for your system, especially if you desire good digital reception; LNB noise ratings alone will not tell you if you have a good LNB or not. For digital reception, just as important or maybe more so is the frequency stability of the LNB. In general, the best bet is to try your LNB(s) and see if the picture quality is acceptable to you. The LNB has an F-type coaxial cable connection for the signal to travel, usually from the feed, underground, and then inside the system owner's home, to the satellite receiver. The fourth component is the dish positioning assembly. This is the physical part that precisely positions the dish when commanded to by the satellite receiver or dish mover. The most common type of positioning assembly is the linear actuator, which connects near its middle to the fixed part of the dish mount, and at its end to the movable portion of the mount or to the reflector. If the satellite system is located in roughly the eastern part of North America, the actuator needs to be aligned with the moving end oriented west; if the satellite system is located in roughly the western part of North America, the actuator needs to be aligned with the moving end oriented east. Refer to your actuator's manual for a visual of these positions or have someone with installation experience help you (not a bad idea, anyway!). Because of the geometry of the polar dish mount, a linear actuator cannot physically move the reflector all the way from one horizon to the other. So, the other type of positioner is known as the horizon to horizon mount, usually some form or worm and sector gear arrangement, which as the name indicates, can track the entire arc between the eastern and western horizons. The fifth component is the cabling. Most installations use a flat ribbon cable comprised of separable sections for each of the necessary functions: 1-two heavy wires for running the actuator motor; 2-two or three small wires to provide dish position feedback to the receiver; 3-two RG-6 coaxial cables for the LNBs; and 4-three small wires to control a servo motor. For installations that use more than two LNBs, a separate RG-6 cable is usually run alongside the ribbon cable for each additional LNB. The sixth component is the satellite receiver. The satellite receiver is arguably the most critical component of any satellite system. The receiver is used to send a picture and sound to your TV or VCR. Some receivers do not contain a dish mover, but many receivers are of the integrated receiver decoder (IRD) variety. Most IRDs contain a built in dish mover to correctly position the satellite dish for view of the satellite arc, tune subcarrier audio (more on this later), and other critical system functions. IRDs are able to not only receive and tune satellite signals, but also either contain an interface for connecting an internal decrypting module for decoding encrypted analog subscription programming, or incorporate a similar apparatus for decoding encrypted digital subscription programming, or both. Most modern IRDs also have at least one remote control to facilitate operation. Many IRD models have a UHF remote and antenna instead of the "standard" infrared remote which allows the IRD to be controlled without even being in the same room as the TV. Some remotes are both infrared and UHF, which allows the UHF portion to be left in another room after using the infrared portion to program a programmable remote for use in the main entertainment area. TVRO receivers are renowned for being quality components for home theater systems. All modern models have composite (RCA) connections to allow connection to devices such as audio/video receivers and external monitors. Some also provide S-VHS connections for convenience with use of other components that have them, even though the composite video connection is capable of providing all the analog signal quality that NTSC video is capable of providing. Okay, I have my equipment. How do I get my TVRO satellite system installed? Easy. Have someone else do it. Pay them lots of money, sit back and when the job is done, watch lots of TV! All kidding aside, many people DO choose to have a professional installation done to avoid the hassle of the installation job. But if you DO do it yourself, you can save a considerable amount of money in parts and labor. http://www.geo-orbit.org/sizepgs/tuningp2.html is a valuable resource discussing polar mount installation. The first step in the installation is to do a site survey. You need to have a clear view to the south in order to properly track the satellite arc. If you are in a thick cover of trees, this will likely affect your reception in some manner. Deciduous (leafy) trees are more problematic in the spring and summer months; conifers (evergreen) can be a problem year round. Even if you plan to do the actual installation yourself, a professional site survey is still recommended. In some instances, a roof mount of some type may be required to get a clear view of the required portion of the satellite arc above any stand of trees. If an acceptable location for dish installation is found, it's time to really get those hands dirty! A simple list of installation hardware and supplies will include a schedule 40 steel pole, several bags of quick-dry concrete (or you can mix some of the regular stuff yourself, if you REALLY want to...), a stepladder, tie wraps, a good set of screwdrivers, wrenches, and other such tools. It is also HIGHLY recommended that you have something for testing signal strength of the satellite signal, such as a dedicated signal strength meter or even an oscilloscope. You should also have an inclinometer when setting declination and offset angles. The most commonly required pole size is 3.5 inches in diameter on the outside. Before you buy one, read the instructions or measure the mount to be sure to get the right diameter. A good rule of thumb is for every foot in diameter of the dish, there should be a corresponding foot in length of the pole. For example, a ten foot dish should have a ten foot pole. Note that part of the pole needs to actually be in the concrete; three feet of pole in the concrete base should work great. Before putting the pipe into the concrete, something needs to be affixed to the bottom of the pipe so that it cannot be twisted by wind load on the dish. Either weld some kind of protrusion to the pipe, or drill a hole through it and stick a bolt or piece of steel rod through. It is highly recommended that PVC pipe be used for cable conduit so that the cabling is protected from the elements, gophers, moles, and any other "varmints" living below the ground. The PVC in the concrete needs to be angled at 90 degrees and only needs to be just inches into the concrete base as the conduit ditch to the system owner's home will only be a few inches deep. 1 inch diameter PVC pipe will suffice, but 1 1/4" or 1 1/2" will make life easier to run long ribbons through. Some hobbyists have an aversion to the PVC technique unless holes are drilled into in the PVC to allow water to drain out. Otherwise, the PVC will fill up with water, and it also makes it more likely that water will seep into the cable at some nick. Before any serious installing can occur, a good hole in the ground needs to be dug for the concrete base. Once dug, it's time to set the metal pole into it. Next, pour the concrete mix into the hole. While the concrete is still wet, insert the PVC pipe to be used for cable conduit, and use a level to make sure the pole is plumb on at least three sides. It will take at least 24 hours for the concrete to completely dry and harden, so don't get into a hurry to finish the dish part of the installation! While the concrete is hardening, unless you did it at the same time you dug the hole for the pole, a shallow trench needs to be dug for the underground cabling; this includes the PVC conduit pipe if used. Lay the cable until it enters the house; make sure to seal entry holes with caulk or other sealer to keep creepy pests and water out. It may be best to adhere to the requirements of your local electrical code when choosing a grounding technique. After the concrete base is good and hard the dish is ready to be mounted onto the pole. If the dish reflector hasn't been assembled, now might be a good time to do this; refer to the dish's instruction manual (if there is one) for assembly instructions. Some designs provide for the mount to be installed on the pole before the reflector is assembled. This is also a good time to connect the feed assembly and LNB(s) to the feed mount. Gently set the mount and/or dish/mount assembly onto the pole. Depending on the size and weight of the dish, and the height of the pole protruding from the ground, this might require three or more people. Point it as close to directly south as possible. After this is done, connect the coaxial portion(s) of your satellite ribbon cable to the LNB(s), connect the servo wires if your feed has a servo motor, and secure the cabling to the dish itself using tie wraps. Connect the actuator arm to the dish and make sure its in the proper orientation. The "hard labor" part of the installation is now done and the system is almost ready to be calibrated to track the satellite arc. But first, the receiver needs to be connected to the proper cables and wires so it can communicate with the dish. No two satellite receivers are exactly alike, but there are some connections that are required by all modern receivers for proper connection to the rest of the satellite system. Here is a list of them: 1. C-Band/Horizontal LNB coaxial input - C-Band or horizontal LNB coaxial cable connects here 2. Ku-Band/Vertical LNB coaxial input - Ku-Band or vertical LNB coaxial connects here 3. Actuator: (red) - Connects to actuator (large red) wire 4. Actuator: (black or white) - Connects to actuator (large white or black) wire 5. Actuator [Sensor]: +5V DC (yellow) (optional, probably not needed) 6. Actuator [Sensor]: Sensor (blue) Connects to actuator (small green or blue) wire 7. Actuator [Sensor]: Shield (gray) Connects to actuator (small brown, tan, or gray) wire 8. Ground: (black) - Connects to polarizer (small black) wire 9. Pulse: (white) - Connects to polarizer (small white or gray) wire 10. +5V, 150mA (red) - Connects to polarizer (small red) wire 11. RF OUT (coaxial) - Coaxial cable out to TV connects here Note that each receiver is different and color-coding may vary. The actuator and polarizer wiring colors also may vary somewhat. Whew! That was a bit tricky! Now connect the receiver to the television and..don't forget to plug in the receiver's power cord! The receiver should now be powered on. Now it's time to calibrate the dish for tracking the satellite arc. This often is the trickiest part of the entire installation. Make sure your satellite dish mount is pointed exactly to the south. Next you must check to see that the west button drives the dish west, and the east button drives the dish east. If the direction is backwards, you'll need to swap the two heavy motor wires, either on the receiver, or on your actuator motor. Next, if your receiver will let you, use your receiver controls to then find the satellite nearest to due south at your location. More commonly the receiver will require you to first set east and west limits. There should be some sort of programming mode on the receiver; this will show up on the television screen as text. If the receiver is brand new, this will probably come up automatically when you first turn it on. If your receiver is used, you'll want to note the satellite name showing when first turned on. If it is the same as the one due south of your location, reprogramming might be very simple. Also if used, the mount might be pointing considerably away from due south, but if that deviance appears to be the same location as the satellite that came up when you powered up the receiver, then also you might have most of your work done already (after ever so slightly loosening the mount on the pole, simply rotating the dish a bit east or west might pop up a picture). If not, most likely you should clear all memory on the receiver before attempting anything else. The following sequence will vary slightly depending on the receiver make and model: 1. Selecting LNB types - Select C/Ku-Band and proper LNB voltage. 2. Setting East/West limits - This tells the receiver the extreme limits of how far the actuator is to move the dish. These MUST be set properly or your dish or mover can be damaged! East limit might be required to be set first, then west. Refer to the receiver manual on the exact procedure for finding the satellite arc. 3. Satellite Programming - Once the arc has been tracked, satellites can be programmed in. In most cases this must be done manually. With some receivers, you need find only two, and then the receiver can find the rest automatically. It may take several hours or more to fine tune the satellite system, particularly for Ku-Band. Just be patient and eventually you will be the proud new owner of a working TVRO satellite system! Congratulations! Okay, I now have my satellite system working. How do I connect more than one TV and receiver to it? There are two main options for a multiple TV setup. You can slave a second TV to the main receiver by splitting the coaxial cable from the "RF OUT to TV" connection so that one cable goes to the primary TV and one goes to the second TV. You can then change channels using your UHF remote. Of course, everyone in the house will have to watch the same channel on both TVs. This setup is not recommended with a IF-only remote system. The other option is to get a second receiver and slave it to the master (main) receiver. The master receiver will have all the connections for positioning the dish, and polarization, if your feed uses a servo motor. DO NOT attempt to dual wire the actuator and/or the servo motor to both receivers as they are NOT designed for this!! This setup allows for viewing different channels on different TVs; however, it is limited to viewing on the same satellite and channels with the same polarity (more on polarity later). For long cable runs you may want to use RG-6 coaxial cable from the splitters to the slave receiver. For shorter runs standard RG-59 cables work fine. All the hype these days is about HDTV. Can I view HDTV signals with my BUD system? Absolutely, yes! For those that haven't yet heard, High Definition Television, or HDTV, is the next generation television broadcasting standard meant to replace the 60 year old NTSC low-definition standard in North America. HDTV has a higher screen resolution than NTSC and uses a wide-screen format with a 16:9 aspect ratio instead of NTSC's 4:3 aspect ratio. The big push for HDTV adoption has been by the National Association of Broadcasters, while only a few cable-type services, mainly HBO and Showtime, have been early adopters of HDTV. The HDD200 is the U.S. model of the 4DTV HDTV add-on. The HDD201 is the Canadian model. They are exactly the same box, they just have different model numbers. The HDD only works with 4DTV or Digicipher equipment (as opposed to VideoCipher II+) as only digital signals can handle the higher data rates needed for HDTV. Besides, HDTV is inherently a digital technology and cannot exist as an analog signal.

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