Why buy an antenna?
In this age of advancing technology, when cable and satellite systems dominate the entertainment landscape, it may seem counterintuitive to consider using an antenna to receive TV signals. But in addition to improving over-the-air reception of standard analog TV signals, there are several great reasons to add an over-the-air antenna for HDTV reception.
- Over-the-air HDTV signals are the best you can get. To offer their
expansive channel selections, cable and satellite systems use data-compression technology to maximize bandwidth on their networks. Compression removes selected parts of the picture information, so the signal you receive is of lesser quality. Only over-the-air broadcasts preserve the full resolution of the signal, delivering all the stunning impact of HDTV.
- An over-the-air antenna provides access to more broadcasts. Due to
contract and licensing restrictions, cable and satellite networks may not always carry all local HDTV broadcasts. Adding an antenna can fill the holes in your cable or satellite service. Plus, depending on your location, a high-mounted rooftop antenna may provide access to out-of-town broadcasts, including (for example) sports programming that may be unavailable in your local broadcast area.
- Over-the-air programming is free of charge. Most prime-time network
shows and sports programming are already broadcast in high definition in most major markets. If you own an HDTV with a built-in or external over-the-air HDTV tuner, an antenna is all you need to view these shows in HD with no ongoing costs or fees (assuming digital signals are available in your area).
Outdoor or indoor?
All other factors being equal, an outdoor antenna will always outperform an indoor antenna. Building materials like metal roofing, aluminum siding, household wiring and foil-backed insulation can weaken or entirely block incoming TV signals. It stands to reason that the less stuff is between your antenna and the TV tower, the better your reception will be.
That said, viewers who live near the broadcast towers of particular stations, or those who live in urban areas saturated with broadcast signals, may
find that an indoor antenna meets their HDTV reception needs. An amplified indoor antenna
includes internal circuitry to boost weak signals for better reception where signals aren't so robust. However, the internal amplifier can indiscriminately boost electrical noise and interference as well as the desired signals, compromising picture quality. Thus, an unamplified rooftop antenna is preferable to even an amplified indoor antenna for best performance.
Selecting an outdoor antenna
There is no single type of antenna that will provide optimum reception for all applications. TV reception is dependent upon many different factors, including:
- the availability and strength of the original signal
- the proximity of the antenna to the broadcast tower(s)
- the direction or directions from which signals emanate
- the presence of obstructions between broadcast tower and antenna
- the presence of reflective structures near the antenna.
Help is a click away
Fortunately, the Consumer Electronics Association (CEA) has created a simple, comprehensive online reference to help consumers easily select an outdoor antenna that will provide the performance they expect. www.AntennaWeb.org
offers a self-explanatory, interactive program that identifies appropriate antenna attributes based on the user's location.
When you visit AntennaWeb.org, you'll be prompted for your ZIP code (and, optionally, more specific information like your street address and proximity to tall buildings, airports and other features that might adversely affect reception). Based on this information, AntennaWeb.org will generate a comprehensive grid of TV signals available in your area. Next to each available station on this grid will be a color code (yellow, green, light green, red, blue, or violet). Each of these colors corresponds to a set of antenna performance characteristics that are ideal for receiving that particular station. Armed with these color codes, you can then return to Best Buy and confidently choose an antenna that will work for your location and the channels you intend to watch, simply by looking for the corresponding color code on the antenna package.
Directional vs. nondirectional
It's common, particularly in densely populated urban areas, for most or all local TV affiliates to broadcast from a shared cluster of towers. This makes it easy to isolate a high-quality signal from several stations at once, using a directional antenna.
As you'd expect from the name, a directional antenna is designed to "see" signals that emanate
from a specific direction. Therefore, for a directional antenna to perform its best, it must be aimed directly at the origin of the desired signal(s). Here again, AntennaWeb.org can help. The same grid that provides the color codes for selecting the proper antenna also indicates, for each available station, the compass orientation of the signal's origin with respect to your particular location. You (or your professional installer) can use this information to precisely orient your antenna, optimizing signal reception.
If the signals you want to receive (as indicated on the AntennaWeb grid) emanate from several different locations, a directional antenna may prove unsatisfactory. A multidirectional (or omnidirectional) antenna that "sees" equally (though less intently) in all directions may allow you to receive all these stations.
Tips for proper outdoor antenna installation
Rooftop or attic?
Attic installation does have a few advantages. Obviously, it's easier and less potentially hazardous to climb into your attic than onto your rooftop. It's also true that an attic-installed antenna will endure less environmental abuse than one that's exposed to the elements, and therefore is likely to outlast its rooftop counterpart.
However, the same factors that compromise the performance of indoor antennas (electrical interference from nearby cabling or appliances; reduced signal strength and integrity due to building materials that absorb or reflect the airwaves) also apply to an attic-mounted antenna. Signal strength can be reduced by 30-50% when compared to roof mounting. Compared to an indoor antenna, an attic-mounted outdoor model has the advantage of larger size and greater "gain" to pull in weaker signals. But ultimately, you'll get better performance from a rooftop-mounted antenna.
The higher, the better
The conditions for optimum television reception can be defined as an unobstructed line of sight between transmitter and antenna. This means exactly what it sounds like: the fewer things are in the way, the better the signal will be. Trees, buildings, hills or mountains — as well as low-flying aircraft, if you live near an airport — in that ideal line of sight can all compromise reception quality. Even the curvature of the earth becomes an obstruction at a critical distance; the theoretical limit of TV transmission is about 70 miles.
Therefore, an ideal location for antenna installation is the highest point on your roof that's not blocked by any of these obstructions from the primary source of the signals you want to receive.
Avoid chimney mounting
Though this may be tempting to achieve maximum loft by affixing your antenna to the chimney, it is not recommended. Heat, particles and gases from the chimney can cause performance problems and premature physical deterioration of the antenna.
Keep your distance from metal
Nearby metallic fixtures, external electrical and phone wiring, pipes, gutters, soffits and duct work can all adversely affect the electrical properties of an antenna. For best results, look for a location that's as remote from these features as practicable.
Use the right cables, and keep them short
The cables that connect your antenna to your tuner can't be eliminated, but they can have the same negative effects as any other nearby metallic object. To minimize signal distortion, find as direct a route as possible and eliminate slack (this will also reduce the danger of damage from high winds). If at all possible, run a single length of cable (rather than multiple shorter runs, spliced together).
75-ohm coaxial cable is superior to flat, 2-conductor 300-ohm cable in terms of both signal conductivity and interference rejection. Even if your home has a pre-existing run of 300-ohm cable, retrofitting with 75-ohm RG-6 cable (as opposed to the thinner RG-59) is highly recommended.
When in doubt, hire a professional
Best Buy's expert professional installers can handle practically any installation. Call our Sales & Installation Hotline at 1-800-276-5107 to schedule yours. Visit our Home Theater Installation page
to learn more about Best Buy's complete range of professional installation services.