An LNB, or Low Noise Block, is an amplifier which receives the radio signal from the satellite after it has been reflected by the satellite dish.<\/p>\n
In addition to amplifying the signal, the LNB also converts the signal to a frequency usable by the In-Door-Unit.<\/p>\n
The functions of the LNB were at one time provided by two separate components, a Low Noise Amplifier (LNA) for signal amplification and a block downconverter for downconversion.<\/p>\n
Most LNB’s used for satellite television include an integrated feedhorn. An LNB with an integrated feedhorn is known an an LNBF.<\/p>\n
All C-band LNB’s have a local oscillator (L.O.) frequency of 5.150 GHz but Ku-band LNB’s may come in many different frequencies, typically fro 9.750 to 12.75 GHz. This means that if you’re attempting to watch a Ku-band service you must set the decoder’s frequency using a bit of simple math. The formula to set the decoders frequency is the downlink frequency minus the local oscillator frequency.<\/p>\n
The quality of C Band LNB’s are measured in degrees Kelvin, with a lower number representing a higher grade LNB. Ku and Ka band LNB’s are measured in decibels, with a lower number also representing a higher quality LNB.<\/p>\n