What is LNB and where it is installed on the dish?
LNB is abbreviated as Low Noise Block. The LNB is an arrangement of low-noise amplifier, local oscillator frequency mixer, and an intermediate frequency amplifier and is installed on the front side of the dish to receive the microwave signals from the satellite. This is a small box suspended on one or more short booms and also feed arms in front of the dish reflector at its focus. Feedhorn pick the microwave signal from the dish and is fed to a section to a waveguide. There are metal pins extended beyond into the waveguide at right angles to the axis and it works as antennas and supply the signal to a PCB inside the LNB’s protected box for better functioning. The lower frequency IF output signal comes out from a socket on the box to which the coaxial cable attaches.
This device is comprised of two types the Linear LNB and the Circular LNB and are easily available from both online and offline shops. On purchasing this you must be careful that a circular feed LNB will not recognize a satellite that requires a linear feed LNB. Different satellite service provider use these popular devices like ExpressVu and Star Choice are famous service providers in Canada, ExpressVu uses a Circular Feed LNB and Star Choice uses a Linear Feed LNB. Similarly in USA Dish Network and Directv uses same type as ExpressVu use. Before you buy you must check its compatibility with your dish so that you may get the best results.
How LNB works?
Low noise blocker gets it power from set top box or from the receiver which is placed inside the house. As this device is installed on the front of a satellite dish so it receives the very low microwave signals from the satellite which amplifies it and then converts the signals to a lower frequency band and then sends them down the cable to the indoor. It is very significant to have the right LNB for the right satellite. This low noise refers the quality of the first stage input amplifier transistor. LNB works as the quality is measured in units which are known as noise figure, noise temperature or a noise factor and both noise factor and noise figure can be transformed into noise temperature. LNB with Noise Temperature which is equal to 100K is far better as one with 200K. C band LNBs tends to have the lowest noise temperature function, whereas Ka LNBs have the highest. This spirit power is sent up the same coaxial wire that holds the obtained indications down to the receiver, getting rid of the need for a separate power wire.
This also works as a filter to reduce noise and distortion in the image and sound. The expression Block submits to the exchange of a block of microwave frequencies as obtained from the satellite which is down-converted to a lower range of frequencies in the wire to the receiver.Â This device owns a potential to transfer the signals received from a variety of downlinked banks like C and Ku to the L band. Low noise blocker works better when it is installed and covered properly to get the best and clear output on your TV screens.