Basic rules for TV signal reception

1. Outdoors is generally better.  Outdoor antennas have a better view of the transmitting station, with no building-induced signal loss. They receive less interference from other household electronic/electrical appliances, and they are less likely to receive reflected ghost signals from the building structure.

2. Higher is better.  The higher an antenna is, the more direct signal it can receive from the TV transmitter, while at the same time reducing the reception of interfering signals from other household electronic/electrical appliances and reflected ghost-causing signals from other nearby structures. The higher the better, but any antenna should be at least four feet above the structure to which it is mounted, and ideally above the roofline.

3. Closer is better.  If a position above the roofline is not possible, the antenna should at least be on the side of your building facing the TV signal broadcast tower.

4. Bigger is better.  The larger an antenna, the more signal it receives. This is especially important on channels 2-6, where the longer wavelength requires a larger antenna in order to be efficiently received. Larger antennas also become directional which reduces ghosting caused by reflected signals coming from the side and the rear of the receiving antenna.

While not difficult to install, antennas are sensitive to installation details. For wood-frame buildings where the antenna will be situated on the roof's peak, the antenna should be at least four feet above the peak. When installed above a flat metal roof, the antenna should be at least ten feet above the roof. For multidirectional antennas, allow for some mounting flexibility so that the antenna can be moved a few feet in each direction in order to obtain the best picture on all channels before a permanent mounting position is selected.

Can I put an antenna in my attic?

Generally, antennas do not perform optimally in an attic. Even when an antenna will perform well outdoors, reception of TV signals in an attic can be made very difficult by interference from other electrical devices. The building's construction can also hinder the entrance of the TV signal or cause reflection of the signal, which leads to ghosting. Depending on building construction, you can expect to lose at least 30% of the signal. In a house with aluminum siding, signal loss could be 100%. Outdoor installation is always best.

What is an amplified antenna and how do I know if I need one?

An amplified antenna can improve a TV set's tuner performance, especially if the antenna is used indoors. Amplified antennas used in yellow color code areas should always be rated for use in these areas. This guarantees that the amplified antenna will not overload the signal. Building construction techniques can seriously reduce the amount of signal that reaches the interior of the building in a yellow color code area, making an amplifier a useful tool.

In dark green color code areas, amplified antennas are highly desirable in order to preserve as much of the received signal as possible, especially when distributing the signal to a VCR and a TV. Also, this can provide some useful compensation for signal loss caused by building construction and position in the building.

In outlying areas a large directional antenna should be used, but this requires amplifiers and rooftop mounting in the blue, violet, and pink color code areas.

What is ghosting?

Many structures can reflect TV signals much like they reflect light. This can lead to the TV receiver "seeing" more than one version of the TV signal. Ghosting results when a TV signal arrives at the receiver via more than one path. Low areas in a neighborhood are especially susceptible to ghosting.

If ghosting is caused by a single structure that creates one distinct ghost image, a medium or large multi-directional antenna may be useful with careful positioning to eliminate the reflected signal. However, the antenna may require different positioning for each channel.

Directional antennas are the most ghost-resistant antennas since they "see" in only one direction and have a tendency not to see the reflected ghost signal. The further away from structures the antenna is located the less likely a problem will occur. Many factors, however, such as the structure's total surface area, the direction it faces, and neighborhood terrain, will influence how much effect the structure will have on TV reception.

Which structures cause ghosting?

Nearby buildings that are higher than the TV antenna or block the antenna's view in the direction of the TV station's transmitter such as:

• Apartment/condominium buildings
• Church Steeples
• School buildings
• Water towers
• Industrial buildings
• Office buildings
• Warehouses
• Large communications/radio/TV towers
• Athletic field lighting towers
• High tension power lines and towers

Which structures do not cause ghosting?

Trees and foliage aren't usually a problem, but in some cases foliage can absorb TV signals and reduce their strength. Therefore, the best antenna locations should avoid foliage in the direction of the TV transmitter. The following usually do not cause ghosting:

• Other homes and wooden buildings that aren't taller than antenna location
• Streetlight or utility poles
• Cellular or PCS poles consisting of a single pole no higher than treetops
• Ham radio antennas
• Other TV antennas