A lot of power is lost by the time the compressed, digital signal travels back from a satellite 22,300 miles out over the equator. The dish is a parabolic reflector and serves as a passive amplifier - the first stage of amplification. The signal that hits the dish is reflected to the LNBF at the focal point, located out in front of the dish. A 24" dish has almost double the gain and since heavy rain blocks the signal, it's very important with DirecTV systems, in some areas, like Florida.

LNBF = Low Noise amplifier Block downconvertor Feedhorn. Today, LNB is the common term. The LNB is the most critical electronic part of a satellite system. A better LNB can improve audio/video quality.

The front part of the LNB is the feedhorn. It's like a funnel that catches the signal that bounces off the dish. The transponders (channels) are polarized circularly, odd number channels going one way and even numbers going the other. Voltage from the receiver in the house switches from 13V to 18V and changes the polarity automatically, when you change the channels. The LNB amplifies the signal and converts it down from the 12 GHz range to 950 - 2,000 MHz.

The downconverted signal can then be run through a high quality RG-6 coaxial cable into the satellite receiver. A dual LNB has two connectors, so you can connect two receivers. With a Magic Switch, (see Multiple Receiver Installation on the link below), you can add more receivers.

There are two primary factors in the LNB to bring in the best audio/video. Noise Temperature, which is measured in degrees Kelvin and amplification, or gain, which is measured in Decibels and calculated logarithmically. High gain is of no value unless the noise temperature is very low. Although they try to make every part perfect, nothing is ever perfect. There are many component parts in an LNB and all have plus or minus tolerances, so there can be big differences in the audio/video quality you see inside. All LNB's that come with 18 inch dish satellite systems provide a good picture and most have a 90 day warranty. The commercial Dual LNB has a 5 year replacement warranty, higher gain and lower noise and when installed with the 24" dish, reception is fantastic.

Certain commercial accounts, like Sports Bars, won't settle for anything less than the best. Can you imagine a bunch of rowdy guys, drinking beer all day and then losing the signal in a middle of a football game?

To help prevent any problems, we offer a commercial Dual LNB that is made to our specifications and checked on a spectrum analyzer. Although individual print outs are not available, typically, these LNB's show 60+ dB and 18 Kelvin.

This is more than twice the gain and a much lower nose temperature than many factory LNB's. Plus, it comes with a five year replacement warranty and built in lightning protection. List price for the 24" dish and a commercial Dual LNB is $299, but your cost is $145 + $25 shipping.

NOTE: 24" Dishes are aimed about 3 degrees higher than 18" dishes. This may help to get over trees and other obstructions.