el bandido
02-19-2013, 09:58 PM
You can buy the best dish antenna system in the country, but it will only work as well as the line that feeds it!
Most of us use some type of RG6 to feed our satellite antenna systems. RG6 has a very high signal loss in runs of 100 feet or more. This high loss of signal is not advertised on the cheap rolls of RG6 that you will find in the local Home Depot or Lowes store.
It is common to see 100 feet of an average RG6 rated at 15db of loss at 2200Mhz. The cheap China stuff that is sold in Lowes or Home Depot may be higher than 15db per 100!
I like to calculate loss of a fta satellite feed line at 2200Mhz because this is should be the highest frequency that most fta feed lines will ever operate at.
15db of signal loss is no small amount. A lot of times we will see people go to the expense of installing a bigger antenna dish which only gives a db or two of gain. It is possible in a lot of fta antenna systems to get a bigger gain in the received satellite signal by changing to a better grade of feed line than by increasing the dish size by a small amount!
One advantage of increasing the dish antenna size is the beam width becomes more narrow, and this effect cannot be duplicated by changing or upgrading the feed line.
Most fta feed lines should be suitable for flooding or direct burial because part of the feed line is ran outside to the dish antenna. Outside conduits can flood and it is not a good idea to bury a feed line that is not rated for direct burial. Some feed lines will have the designator U such as RG6U. The U does necessarily stand for underground burial.
CommScope makes a RG11 coax cable that has a low db loss per 100 feet and also has a flood and direct burial rating. I purchased a 1000 foot roll of CommScope 5917 RG11 because I do not want a feed line with a loss of 15db or more! The CommScope 5917 RG11 db loss per 100 feet is advertised to be 6.29 db at 2200Mhz which is what I consider to be acceptable for a fta satellite system.
Some people are not familiar with the installation of RG11. I plan to take some pictures and make some notes while I am installing some of this coax. The connectors for RG11 are more expensive and install a bit different than RG6 connectors but the end result is the same except for the db loss!
It should be noted that not all RG6 or RG11 is good for fta satellite antenna systems. It is common to find RG11 that is only good up to 1000 Mhz. Most of our fta receivers operate between 950 and 2150 Mhz. To be safe, get a coax that is swept to 3000Mhz or 3Ghz.
Attached is a .pdf detailing the CommScope 5917 RG11 cable specs.
I would also like to say Thanks to Mike at MJ sales INC in Pearce, Az. This company will supply professional grade feed line parts to the fta community and will ship to Canada. EB
Most of us use some type of RG6 to feed our satellite antenna systems. RG6 has a very high signal loss in runs of 100 feet or more. This high loss of signal is not advertised on the cheap rolls of RG6 that you will find in the local Home Depot or Lowes store.
It is common to see 100 feet of an average RG6 rated at 15db of loss at 2200Mhz. The cheap China stuff that is sold in Lowes or Home Depot may be higher than 15db per 100!
I like to calculate loss of a fta satellite feed line at 2200Mhz because this is should be the highest frequency that most fta feed lines will ever operate at.
15db of signal loss is no small amount. A lot of times we will see people go to the expense of installing a bigger antenna dish which only gives a db or two of gain. It is possible in a lot of fta antenna systems to get a bigger gain in the received satellite signal by changing to a better grade of feed line than by increasing the dish size by a small amount!
One advantage of increasing the dish antenna size is the beam width becomes more narrow, and this effect cannot be duplicated by changing or upgrading the feed line.
Most fta feed lines should be suitable for flooding or direct burial because part of the feed line is ran outside to the dish antenna. Outside conduits can flood and it is not a good idea to bury a feed line that is not rated for direct burial. Some feed lines will have the designator U such as RG6U. The U does necessarily stand for underground burial.
CommScope makes a RG11 coax cable that has a low db loss per 100 feet and also has a flood and direct burial rating. I purchased a 1000 foot roll of CommScope 5917 RG11 because I do not want a feed line with a loss of 15db or more! The CommScope 5917 RG11 db loss per 100 feet is advertised to be 6.29 db at 2200Mhz which is what I consider to be acceptable for a fta satellite system.
Some people are not familiar with the installation of RG11. I plan to take some pictures and make some notes while I am installing some of this coax. The connectors for RG11 are more expensive and install a bit different than RG6 connectors but the end result is the same except for the db loss!
It should be noted that not all RG6 or RG11 is good for fta satellite antenna systems. It is common to find RG11 that is only good up to 1000 Mhz. Most of our fta receivers operate between 950 and 2150 Mhz. To be safe, get a coax that is swept to 3000Mhz or 3Ghz.
Attached is a .pdf detailing the CommScope 5917 RG11 cable specs.
I would also like to say Thanks to Mike at MJ sales INC in Pearce, Az. This company will supply professional grade feed line parts to the fta community and will ship to Canada. EB