There are two kinds of amplifiers that are primarily used for off-air terrestrial TV signals, PRE-AMPLIFIERS and DISTRIBUTION AMPLIFIERS.

A PRE-AMPLIFIER, sometimes called a BOOSTER or PRE-AMP, is a mast or 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.   However sometimes a TV or satellite receiver's signal strength meter can suffice.  Each TV or Satellite receiver signal meter can vary and it’s reading may only be relative to how the meter is calibrated.   Typically however, you will want to see the signal reading above the 80 % range.   Although the meter is the recommended method of determining amplifiers 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 of the analog channels are not too “snowy”, then there is a good chance that a PRE-AMP can 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 picture 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 commonly called, “tiling” 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 DIRECTV satellite receiver by using a PRE-AMP and REGULAR DIPLEXER.   The Pre-amp diplexer supplies power through one port to the Pre-amplifier.   The diplexers allow the antenna and satellite signals to travel down the same coaxial cable.   Use of diplexers is only recommended for more experienced installers.  

A DISTRIBUTION AMPLIFIER, often referred to simply as an AMP, is mounted indoors usually in a central location.   Its primary function is to distribute modulated TV signals to multiple locations.  Typically the best method of determining whether you need a distribution amp is to use a signal strength meter to test each TV outlet.   The goal is to have at least 0db of signal present at each outlet for each channel you’re trying to receive.   If there isn’t sufficient signal at each outlet a distribution amplifier can, in many cases, solve the problem by amplifying the signal. 

If a meter is not available, you can try this.   First, remove any signal splitters that may be connected to the TV antenna and connect the antenna directly to one TV.  If the TV reception is good on the one TV, reconnect the splitter or splitters and check the reception on the other TV's. If you see a noticeable difference between the TV being connected directly to the antenna and when the splitter or splitters were connected, then a DISTRIBUTION AMP may solve the problem.  Again, without a meter, this is a trial and error method.

There are many different types of DISTRIBUTION AMPS, some are designed to amplify OFF-AIR TV ANTENNA signals only and some are designed to amplify OFF-AIR and CABLE TV channels. The Amplifier is inserted between the ANTENNA / SOURCE and the splitter or splitters.  Some Amplifiers actually have built in splitters.

NOTE: Pre-amplifiers and Distribution amplifiers only work properly when they have enough, and not too much, signal input into them to function correctly.   They cannot actually produce signal and if too much “noise” rather than signal is provided at the input, then the output will be amplified noise.     We always recommend a qualified installer with the proper equipment to achieve the best results.