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Typical suggestions for setting up a satellite dish for fta are: Properly aim the dish at the target satellite and adjust the dish for maximum Q signal strength on your fta receiver. These are a couple of very basic steps that can lead to a tv signal being received from the satellite. The signal from the satellite may or may not be at its maximum strength after doing these things.
The lnb is an important piece in any satellite system. The job of the lnb is to receive satellite signals, amplify them, and convert the received signals to a lower frequency that the fta receiver can understand. A typical fta lnb may cost under twenty U.S. dollars and be advertised to have a nf rating of .1db. There may also be some advertisements that say how well the lnb works and that it increases the satellite signal.
All fta lnbs increase the satellite signal because they have amplifiers in them. The lnb that is best suited for a particular dish will be matched as close as possible for the specifications of the dish.
A satellite dish should have a f/d ratio in its spec sheet. About the best matching we can do in a typical offset dish fta system is to find a lnb that has a f/d ratio that equals the f/d ratio of the dish. This is not as easy as it sounds because the spec sheet for some dishes are not easily found, and the f/d ratio of a particular lnb is not easy to find either. A satellite dish system that has the lnb matched to the dish will usually work better than systems where the lnb is not matched to the dish.
The coax or feed line that connects the satellite receiver to the lnb is a very critical area that is often overlooked in fta dish systems. RG59, RG6, and RG11 are all common types of coax cables that are used in fta systems. What type of coax cable you will need depends on the distance between the fta receiver and the lnb. It is a good idea to calculate the loss of your coax cable before you install it. Usually replacing a dish with another one that is a size or two bigger only results in a gain of 2-3 db. Replacing a coax cable that has lots of signal loss with one that is more efficient may result in a signal gain of 5 to 10db, depending on the system and circumstances.
The way to calculate the effective db gain of a satellite dish system is to add all the db gains and subtract all the db losses.
For example, we have a dish that gives 30 db of gain and a lnb that has a rating of 50 db gain. This would give us a total of 80 db in gains.
The same fta system has a loss of 10 db in the coax feed line, 3 db of loss in a switch, and another 1.5 db of loss in the connectors. The total losses in db would be 14.5
Subtract 14.5 from 80 and you have an effective 64.5 db gain for this satellite antenna system.
Noise is a big concern in satellite dish systems. The ground or the area behind the dish has more noise than the sky, so we want the lnb to illuminate as much of the dish as possible without illuminating any area behind the dish. A lnb that is not matched to a satellite dish will probably illuminate either part of the dish or the entire area of the dish, and part of the area behind the dish.
Most fta receivers have a Q signal meter that is supposed to represent the received strength of the satellite signal. In reality, these Q signal meters show the strength of the signal from the satellite, plus the noise that is being generated in the dish antenna system. This is one reason why it is possible to have a Q signal reading of 80 on a 30 inch dish when aimed at a particular satellite and a Q signal of 80 on a 1.2 meter dish aimed at the same satellite signal and using the same fta receiver.
A mismatched lnb may also show a high Q signal reading when the actual satellite signal is poor. I have seen a Q signal of 75-80 with a prime focus ku lnb installed on a 1.2 meter offset dish, but the picture was pixelating. Proper matching of the dish parts is important!
Also, some lnbs work better on long runs of coax over 125ft or 40 meters. These lnbs may show a higher Q signal on a short run of coax when compared to another lnb.
BER can be an abbreviation for Bit Error Rate. In short, a BER signal meter analyzes the received signal for errors. The lower the error rate, the better the signal is being received. I think BER is a much better way of looking at the received satellite signal than the unreliable Q signal meter. It is possible to have a high Q signal reading, and at the same time have a high BER.
Most fta receivers do not have a BER function that works but this feature is beginning to be available in some fta receivers.
Simple and inexpensive things usually work pretty good in a fta dish antenna system. It is a good idea to know how much and where your db losses are in your antenna system. It is also a good idea to match the parts so they will work well together, and at the same time, try to minimize your losses. EB
The lnb is an important piece in any satellite system. The job of the lnb is to receive satellite signals, amplify them, and convert the received signals to a lower frequency that the fta receiver can understand. A typical fta lnb may cost under twenty U.S. dollars and be advertised to have a nf rating of .1db. There may also be some advertisements that say how well the lnb works and that it increases the satellite signal.
All fta lnbs increase the satellite signal because they have amplifiers in them. The lnb that is best suited for a particular dish will be matched as close as possible for the specifications of the dish.
A satellite dish should have a f/d ratio in its spec sheet. About the best matching we can do in a typical offset dish fta system is to find a lnb that has a f/d ratio that equals the f/d ratio of the dish. This is not as easy as it sounds because the spec sheet for some dishes are not easily found, and the f/d ratio of a particular lnb is not easy to find either. A satellite dish system that has the lnb matched to the dish will usually work better than systems where the lnb is not matched to the dish.
The coax or feed line that connects the satellite receiver to the lnb is a very critical area that is often overlooked in fta dish systems. RG59, RG6, and RG11 are all common types of coax cables that are used in fta systems. What type of coax cable you will need depends on the distance between the fta receiver and the lnb. It is a good idea to calculate the loss of your coax cable before you install it. Usually replacing a dish with another one that is a size or two bigger only results in a gain of 2-3 db. Replacing a coax cable that has lots of signal loss with one that is more efficient may result in a signal gain of 5 to 10db, depending on the system and circumstances.
The way to calculate the effective db gain of a satellite dish system is to add all the db gains and subtract all the db losses.
For example, we have a dish that gives 30 db of gain and a lnb that has a rating of 50 db gain. This would give us a total of 80 db in gains.
The same fta system has a loss of 10 db in the coax feed line, 3 db of loss in a switch, and another 1.5 db of loss in the connectors. The total losses in db would be 14.5
Subtract 14.5 from 80 and you have an effective 64.5 db gain for this satellite antenna system.
Noise is a big concern in satellite dish systems. The ground or the area behind the dish has more noise than the sky, so we want the lnb to illuminate as much of the dish as possible without illuminating any area behind the dish. A lnb that is not matched to a satellite dish will probably illuminate either part of the dish or the entire area of the dish, and part of the area behind the dish.
Most fta receivers have a Q signal meter that is supposed to represent the received strength of the satellite signal. In reality, these Q signal meters show the strength of the signal from the satellite, plus the noise that is being generated in the dish antenna system. This is one reason why it is possible to have a Q signal reading of 80 on a 30 inch dish when aimed at a particular satellite and a Q signal of 80 on a 1.2 meter dish aimed at the same satellite signal and using the same fta receiver.
A mismatched lnb may also show a high Q signal reading when the actual satellite signal is poor. I have seen a Q signal of 75-80 with a prime focus ku lnb installed on a 1.2 meter offset dish, but the picture was pixelating. Proper matching of the dish parts is important!
Also, some lnbs work better on long runs of coax over 125ft or 40 meters. These lnbs may show a higher Q signal on a short run of coax when compared to another lnb.
BER can be an abbreviation for Bit Error Rate. In short, a BER signal meter analyzes the received signal for errors. The lower the error rate, the better the signal is being received. I think BER is a much better way of looking at the received satellite signal than the unreliable Q signal meter. It is possible to have a high Q signal reading, and at the same time have a high BER.
Most fta receivers do not have a BER function that works but this feature is beginning to be available in some fta receivers.
Simple and inexpensive things usually work pretty good in a fta dish antenna system. It is a good idea to know how much and where your db losses are in your antenna system. It is also a good idea to match the parts so they will work well together, and at the same time, try to minimize your losses. EB
