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New member Username: LearningsatsSacramento Post Number: 1 Registered: Aug-05 | OK, I know there will be someone who will call me stupid but I am totally new to satellites and I need to learn a few things that I always see on forums or other sites so I will know what to get and what others are talking about. Please explain the following terms for me: 1. What is an LNB? I think its the little round things that point back toward the dish. If so, how many types of LNBs are there and what do each do? 2. Are there any real differences in the many satellite receivers I see advertised such as Pansat, Fortec, Digiwave, etc when it comes to getting FTA stations? Does one give you access to more FTA stations than another? 3. In dry weather can a 30 inch dish pull more stations than an 18 inch dish? Does the extra size just help bring clarity during rainy weather? If someone could help me with just these few questions I think I will be off to a good start in the satellite club. Thanks, David |
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LK Unregistered guest | Yes,those are the LNB's...they actually receive the satellite signals,not the dish...the signals bounce off the dish towards the LNB (remember geometry)and then a cable from the LNB carry the signal to the receiver. There are basically 2 types,universal (linear) and standard (circular)..One picks up lower frequencies,the other higher frequencies..Each satellite has transponders of groups of 13,which sends different frequencies for different channels.. No there is Basically very little difference in FTA receivers,its like cars,they all do the same thing,get U to your destination..access to more channels is entirely based upon how many LNB's and satellite dishes U have and how they are aligned towards all the various satellites listed at lyngsat. com...obviously the best thing is a motorized big dish with many LNB's.. Bigger is better with dish sizes,so 30 is better than 18...the bigger dish can pick up weaker signals from various satellites in all weather.. |
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LK Unregistered guest | LNB= Low Noise Block...and is the actual antennae |
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New member Username: LearningsatsSacramento Post Number: 2 Registered: Aug-05 | Thanks a lot LK |
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Big Bwana Unregistered guest | Actually they both pick up the same frequencies not higher and lower it's all Ku band signals just one's polarized horizontal and vertical ( Bell/ Dish/ DTV ) and the others Clockwise and counterClockwise ( Starchoice, Voom, And old DTV equiptment, and those C Band add on units for FTA ) This is not Including the new Stacked LNB's which don't change from horizontal to vertical or clockwise to counterclockwise, they simply place it on a high output band 2,450 MHz. Or the Reversed LNB's used on the Tordorial dishes ( same as other LNB's only they are reversed because of a second reflector ) and LNB would be used in other signals like C band X band or K band but most people won't play in those areas. and with the FTA's you can get options like C Band not that there's much on the old C Bands, and you can get upgradeable unit's but there are all pretty much the same. and the 18 or 30 inch the 30 is better but a good small dish like a 24 inch channel master, Fiberglass or a 12 inch RCA radar unit will do just as good. ( Some of the pressed Steel dishes 24 inches and larger are not much better due to manufacturing tolorances and cost cutting ) and a 1.8 Meter channel master is the cats a$s. |
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Anonymous | WOW ! |
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LK Unregistered guest | Circular & Linear LNB's: What's the difference? -------------------------------------------------------------------------------- OK everyone, put your polarizing sunglasses on. What's the difference? Answer: About -3dB or half the signal level. Now take your sunglasses off. Notice how bright it is in here? The difference in brightness is an example of using the wrong lnb type. Circular and Linear polarization refer to the characteristics of the radio wave that is transmitted by the satellite towards your dish/LNB. Below are links to visual comparisons of Circular (Left or Right-hand) and Linear (Vertical or Horizontal) polarization. http://www.barco.com/projection_sys...r&circulair.jpg http://repairfaq.cis.upenn.edu/sam/icets/VHB6-6.gif Circular polarization refers to a wave of radio signal rotating in a spiral. This spiral can be rotating in either the clockwise ("R"ight-hand) or counterclockwise ("L"eft-hand) direction. Think of an approaching airplane as the plane's propellar is moving towards you. The following example satellites (visable in N.America) are transmitting with a circular polarized signal: EchoStar 3 @61.5°W http://www.lyngsat. com/echo3.html Nimiq 2 @82.0°W http://www.lyngsat. com/nimiq2.html Nimiq 1/3 @91.0°W http://www.lyngsat. com/nimiq1.html EchoStar 6/8 @110.0°W http://www.lyngsat. com/110west.html EchoStar 7 @119.0°W http://www.lyngsat. com/echo7.html EchoStar 1/2 @148.0°W http://www.lyngsat. com/148west.html How do I know they are circularly polarized? If you click on any one of the links for the satellites above you will notice that under the first column labeled as "Freq. Tp" you will find one of the following single letter designations: "R" = right-hand (=circular polarization) "L" = left-hand (=circular polarization) So what about linear polarization? Linear polarization refers to a wave of radio signal rotating in a single plane. Think of an approaching helicopter as the helicopter's main rotor is moving towards you. It is rotating in a single, horizontal plane. The same approaching helicopter's smaller rear rotor is rotating in a single, vertical plane. In our satellite case it can be either in the "H"orizontal or "V"ertical plane. The following example satellites (visable in N.America) are transmitting with a linear polarized signal: SBS 6 @74.0°W http://www.lyngsat. com/sbs6.html AMC 5 @79.0°W http://www.lyngsat. com/amc5.html AMC 9 @85.0°W http://www.lyngsat. com/amc9.html IA 6 @93.0°W http://www.lyngsat. com/ia6.html IA 5 @97.0°W http://www.lyngsat. com/ia5.html AMC 1 @103.0°W http://www.lyngsat. com/amc1.html AMC 2 at 105.0°W http://www.lyngsat. com/amc2.html EchoStar 9 @121.0°W http://www.lyngsat. com/echo9ia13.html Again, under the first column labeled as "Freq. Tp" you will find one of the following single letter designations: "V" = vertical (=linear polarization) "H" = horizontal (=linear polarization) Now that you understand the difference between the two satellite polarization types please put your polarizing sunglasses back on. Hmmm, a little harder to read this right? Well, that's what happens to your receiver when you try to use a linear polarized LNB to receive a circular polarized satellite signal and vis-a-versa. About a 50% loss of signal! Armed with the invaluable information you now possess, by using this link http://www.lyngsat. com/america.html you can determine for yourself what type of LNB you will need for each satellite. If you need a circular polarized LNB look for words describing it as "DSS" or "DBS" or "circular" or a combination of these terms. If you need a linear polarized LNB look for words describing it as "FSS" or "FTA" or "linear" or a combination of these terms (FYI: All Universal LNB's are linear LNB's). |
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LK Unregistered guest | Understand LNBs: Standard Linear, Circular, Stacked, and Universal. LNB and LNBF? -------------------------------------------------------------------------------- There are 2 different groups of KU band satellites, FSS (Fixed Satellite Service) and DBS (Direct Broadcast Satellite). DBS satellites are the type satellites used by DN, DTV, BEV, and VOOM, and the band is authorized for use in North America. They operate from 12200-12700 MHz, and their polarity is circular. FSS satellites are thought of as general purpose satellites and is the home of many different broadcast media and many different types of signals. The FSS satellites are placed worldwide around the globe. The frequency is 10700-12700 MHz and the polarity is linear. Here in NA we primarily use the portion of the band from 11700-12200 MHz. A few signals from satellites over the Atlantic can be found in the 11200-11700 MHz portion, but there are not very many. Linear polarity satellites broadcast their signals with the waveform being sent from the antenna either in the vertical plane (oriented up-down) or the horizontal plane (oriented left-right). This allows twice the amount of channels to be transmitted by the satellite in the same amount of bandwidth, as the signals from the opposite polarity are attenuated enough so that they don't interfere with each other. Circular polarity satellites send their signal in a corkscrew pattern, and the polarity is determined by the direction of rotation of the signal, either right hand or left hand. When the signal is reflected from the dish, it enters what is called a feedhorn. The feedhorn, or feed for short, focuses the received signal down a tuned tube, which is called a waveguide. We sometimes refer to the waveguide as the THROAT of the feedhorn. At the end of the waveguide is the entrance to the amplifier. The amp usually has 2 probes that is each oriented to correspond to the horizontal and vertical polarities, and is switched by the amplifier according to which polarity is needed. A circular feedhorn has a small device that transforms the circular signals to either horizontal or vertical signals for processing by the amp. The amplifier is generally called an LNA (low noise amplifier). The amp does it's job and amplifies the very weak microwave signal, and then it's passed on to a device called a downconverter. A microwave signal has extremely high loss when trying to send it down a regular coax. After just a few feet there would not be much signal left because of this loss. Lower loss coax could be used, but it would be extremely expensive. The downconverter "converts" the signals to a much lower frequency so that relatively inexpensive coax can be used to get the signal from the dish to the receiver. Todays technology has allowed the combining of the LNA and downconverter into the same box. This is called an LNB, or Low Noise Block converter. And feeds are now being integrated with LNB's into a single assembly known as an LNBF. C Band dishes work on basically the same principle above, except the feeds and dishes are MUCH bigger, and use a much lower frequency of 3400-4200 MHz. They can also be either linear or circular polarity. You must have the proper LNBF for the type of satellite you want to receive. A DBS LNBF won't receive much of anything in the FSS band, and vice versa. 2 LNBF's are required to receive both bands. There are generally just 1 type of DBS LNBF, but there are 2 types of FSS LNBF's, standard and universal. A standard LNBF will cover a single portion of the FSS band, usually 11700-12200. It has a single local oscillator frequency, which is usually 10750 MHz. A universal LNBF is an offshoot of LNBF's that are mainly used in Europe, where they have a need to tune several sections of the KU FSS band with a single LNBF. They will tune 10700-12700 MHz. and they have 2 seperate local oscillators at 9750 and 10600 MHz, which will allow the LNBF to tune a large expanse of spectrum. The receiver uses a special signal to tell the LNBF which of the local oscillators it should use for the frequency it needs to tune. See this post for more information and my thoughts about universal LNBF's... Some of this stuff might be a little difficult to understand, as it's a lot of information in a short space. As you learn about terms in satellite TV, maybe this will be a reference you can come back to and help you understand things a bit better. The standard Lnb's set frequencies are: FSS Ku-band linear LO 10750MHz DBS circular LO 11250MHz An euro-'universal' LNB will have two LO's and may be configured using the default values stored in the receivers A stacked LNB uses the standard frequencies for vertical/right-circular polarisation, then move up values(depends on the oscilator) for the horizontal/left-circular transponders. For DBS 12.2-12.7 GHz For FSS 11.7-12.2 GHz LNBs. Oscillator runs to 24600. For FSS 11.2-11.7 GHz LNBs Oscillator runs to 23600 Actually,they are used for lower and higher frequencies as well!..linear (lower) vs circular (higher) |
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Anonymous | Any help would be appreciated I just heard about fta receivers and got one, but I have no idea how to point the dish could anyone explain a fairly simple way |
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New member Username: Rcdriver11Post Number: 1 Registered: Aug-05 | also do I need any software with my receiver I have a pansat 3500 |
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Big Bwana Unregistered guest | LK. some one's been reading, now what do you know about LO Jamming ? ( Neat russian trick for wiping out SAT Tv for miles and miles, with only a small 1 to 2 Watt transmitter ) And as for the LO the Maxim tuner is very atapable, and it's used in both DTV, Echostar, Motorolas and even the Play Station ( Japan Version ) Yes it to has a SAT tuner built in And DVD Burner ) It's all in the software controling. people might remeber way way bad in the day when you had to change LNB's on dish because of the switch over, some thing about people not understanding turn your LNB CW or CCW a few degrees. Go Figure ( the new ones From Cal Amp are able to adjust themself ) |
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Unregistered guest | I am also a newbie and have hooked up pansat 2500a I am getting a level of 80% and quality of 75% but still no stations when i do a scan most channels are $... do i need to get the quality and level higher for stations??? Please Help Newbie Thanks |