Whether you're a commercial installer or just a hobbyist, you may have decided that an amplifier and polarity locker are the right choice for you. A polarity locker powers the dish and makes sure that the four cable lines coming down to the SWM are specifically set to only carry the frequencies and polarities needed (each line only needs one of the four possible ones.) An amplifier, like the Sonora SA-6AL shown above, normalizes the signal and makes sure it's strong enough to go all the way to the SWM. Both are good ideas for any installation where there's a long run from SWM to dish, and in commercial installations, they're critical.
Traditional wisdom has always been that you put the amplifier first, and it is powered by the polarity locker. Recently, commercial installers have begun to talk about a new installation scheme where the polarity locker is closest to the dish and the amplifier comes afterwards. This would mean the amp needs its own power supply.
Why would this be a better installation? Locking the polarities before introducing noise into the system sounds like a good idea, and even the best amplifier adds some noise to the line. Using separate power supplies also means that if the polarity locker goes down, it's not taking the amplifier with it. That also makes sense.
There are some very highly placed people who really think this is a better way to go, and DIRECTV's latest installation documents now show the polarity locker first with the amp after it. What do you think? If you have a working installation with the amp first would you move it? Are you inclined to change the way you install new commercial systems? Let's hear from you!