saajid
07-13-2011, 11:18 PM
Satellite Dish Installation Guide
Selecting your Dish Antenna for Satellite TV Reception
It is important to invest a little bit of some thought here prior to choosing your satellite dish to avoid unnecessary expense later on; the type of satellite dish you use - and receiver - will eventually determine the kind of TV programming you will be able to receive.
Low Noise Block-down Converters: A few basics
Equally important is deciding on the number of LNBs. LNB's/LNBF are low noise 'block' down-converters. An LNBF is an LNB with an integrated feedhorn. Most LNB's in use today are actually LNBF's. The term 'low noise' relates to the quality of the amplification and mixing that takes place inside the LNB.
LNB's sit in front of the actual parabola of the dish, at the end of the arm projecting from the satellite dish. Their purpose is to receive, amplify and down convert the required 'blocks' of microwave frequencies to lower 950MHz to 1.45GHz L-band frequency signals; these are then sent to the satellite TV receiver or IRD (integrated receiver decoder), via RG-6 coax cable.
The number of LNB's determines the number of satellites a satellite dish can 'see' since a separate LNB is required to receive signals from satellites in different orbital positions. 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.
Different Types of Satellite Dishes
Currently, DirecTV offers eight type of dishes while DISH Network has ten. Dishes range in size from 18-inch to 36-inch x 22-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 18-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.
You cannot split a satellite TV signal through an ordinary RF splitter as used in terrestrial TV reception. 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.
http://www.practical-home-theater-guide.com/image-files/satell9.jpg
When choosing your satellite dish, do not buy the round dish if you are getting a new DirecTv system - only the slightly larger oval or rectangular antenna dishes will able to pick up all D@veTV standard and HD programming.
These satellite dishes come with 5 LNBs to receive both KU-band (101
Selecting your Dish Antenna for Satellite TV Reception
It is important to invest a little bit of some thought here prior to choosing your satellite dish to avoid unnecessary expense later on; the type of satellite dish you use - and receiver - will eventually determine the kind of TV programming you will be able to receive.
Low Noise Block-down Converters: A few basics
Equally important is deciding on the number of LNBs. LNB's/LNBF are low noise 'block' down-converters. An LNBF is an LNB with an integrated feedhorn. Most LNB's in use today are actually LNBF's. The term 'low noise' relates to the quality of the amplification and mixing that takes place inside the LNB.
LNB's sit in front of the actual parabola of the dish, at the end of the arm projecting from the satellite dish. Their purpose is to receive, amplify and down convert the required 'blocks' of microwave frequencies to lower 950MHz to 1.45GHz L-band frequency signals; these are then sent to the satellite TV receiver or IRD (integrated receiver decoder), via RG-6 coax cable.
The number of LNB's determines the number of satellites a satellite dish can 'see' since a separate LNB is required to receive signals from satellites in different orbital positions. 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.
Different Types of Satellite Dishes
Currently, DirecTV offers eight type of dishes while DISH Network has ten. Dishes range in size from 18-inch to 36-inch x 22-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 18-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.
You cannot split a satellite TV signal through an ordinary RF splitter as used in terrestrial TV reception. 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.
http://www.practical-home-theater-guide.com/image-files/satell9.jpg
When choosing your satellite dish, do not buy the round dish if you are getting a new DirecTv system - only the slightly larger oval or rectangular antenna dishes will able to pick up all D@veTV standard and HD programming.
These satellite dishes come with 5 LNBs to receive both KU-band (101