How To Buy a Rooftop Antennaby David Lipscomb
Over-the-air television is an excellent option for free viewing of a wide range of high-definition programming. However in order to receive it, you need the right antenna pointed in the right direction. This is not as easy as in the old analog days, where close enough was good enough. Today's digital broadcasts require precise aiming to minimize picture breakup caused by the directional nature of digital broadcasting. Because digital broadcast operates almost equally in the VHF and UHF bands, your antenna must adequately receive both. Other factors such as surrounding trees and structures create picture loss from signal bounce, called multipath. All of this translates into doing proper diligence in selecting the right rooftop antenna, letting the crystal-clear images to shine though your HD television.
Setting the path to finding the right rooftop antenna starts with measuring the intended antenna-installation height. You'll need to know if it's more or less than 30 feet, because the higher the antenna is installed the less likely the signal is to suffer as much interference as it would at ground level. AntennaWeb is a consumer-information site cosponsored by the Consumer Electronics Association, and it can guide you through the maze of confusing antenna options. Entering your physical address and mounting height helps the site generate the best antenna options for you, each assigned a color code. Match this color to the one on retail antenna packaging to locate the right antenna array for your address.
Directional antennas are generally larger, with the payoff coming in the form of more reception power. However, your local broadcast towers need to be within a 20 degree radius as depicted on a map to maximize the benefits of a directional array. If your location is like many others and has a few antennas outside of this radius, you'll need an omnidirectional antenna. These devices are generally less powerful, but do not require meticulous aiming to the same degree as their directional brethren. Both antennas may be mounted to a rotor to maximize reception in urban areas or in environments featuring multiple opportunities for the signal to bounce around.
You may find that for aesthetic or performance reasons you want your antenna installed in your attic. Make sure that the unit you select will actually fit in this environment. Since the FCC ruled in 1996 that homeowner's associations cannot prevent you from mounting an antenna, you don't need to get the unit off your roof for reasons other than safety, performance or personal preference. Should your home have metal siding, it's best to go ahead and mount the array on your roof as far from the siding as possible. If you have a relatively clear line-of-sight to broadcast towers, you might even be able to use a square directional antenna mounted on a bracket as opposed to a conventional mast. Remember that any antenna performs best mounted as high as is feasible, using the largest possible array. You can plug a signal meter into the output of the antenna using a short piece of coaxial cable, measuring the strength in decibels of individual or multiple channels.
Preamplifiers are effective in mitigating the effects of long coaxial cable runs between the antenna and the primary tuner. If you're 50 to 75 miles away from most of the area's broadcast towers, a preamp is also a good choice. At the other end of the cable prior to entering the tuner, an amplifier boosts the feed, maximizing what signal is available. If you need to split the signal a few ways between multiple tuners, select an amplified coaxial distribution hub as opposed to a splitter.
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