A Word About Pre-Amps

Home  >  Electronics Articles  >  A Word About Pre-Amps


 
A Word About Pre-Amps

A pre-amplifier, sometimes called a Booster or Pre-Amp, is a mast antenna mounted amplifier that is used to strengthen the signal at the antenna before the signal has a chance to weaken through the coax cable run between the antenna and the TV.

We strongly recommend the use of a stand-alone signal strength meter to determine whether a Pre-Amp is needed. Although a meter is the recommended method of determining amplifier's needs, if no meter is available you can try this method: Connect your antenna to one TV and point the antenna in the direction that the desired channels come in the best. If some or all the analog channels are not too "snowy", then there is a good chance that a PRE-AMP can help help remove some or all of the "snow" or noise in the analog TV signal.

Note: Digital and HDTV signals are either perfect when you receive them, or you do not see any pictures at all. In other words, you do not see any "snow" or noise in your picture. The one condition that can exist when the signal is border line, is a "freeze frame" or fragmented picture. This condition is common called, "tilling" and will appear to lock on your screen. A Pre-Amp may help boost the signal to the needed levels in this case as well.

Pre-Amps consist of two parts, the actual amp that is mounted at the antenna and the power supply that is mounted inside the house or building. The power supply is often mistaken as an amplifier as it has two coax connectors and an AC plug however this power supply is used to provide voltage through the coax cable to the Pre-Amp. A Pre-Amp can receive power from a Dish Network or DirectTV satellite receiver by using a Pre-Amp diplexer and regular diplexer. The Pre-Amp diplexer supplies power through one port to the Pre-Amplifer. The diplexers allow the antenna and satellite signals to travel down the same coaxial cable. Use of diplexers is only receommended for more experienced installers.