A: Don't get yourself killed.
Seriously, there are two hazards you might underestimate
1. The risk of falling. If you don't regularly work on a ladder, you won't know how easy it is for something to go wrong when you're up high.
2. The risk of electrocution. TV antennas often require long masts. You don't have to be that close to an electric line for a misstep to make that mast fall across the line, and then you're fried (maybe). So be careful or get a professional installer.
Q: What are the basic rules for TV signal reception?
A: 1. Outdoor is generally better. Outdoor antennas456棋牌 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.
456棋牌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.
Once the type of antenna you need is selected using this guide, careful attention must be paid to its installation. 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.
Q: Can I put an antenna in my attic?
A: 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.
Q: What is an amplified antenna and how do I know if I need one?
A: 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.
456棋牌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 and violet color code areas.
Q: Are there some areas not suitable for TV antennas?
A: High-rise buildings can cause a severe ghosting environment. While most of these cases can be solved by suitable directional antenna selection, there are a few cases where an antenna may not provide workable reception.
456棋牌White color code areas are also not suitable for TV antennas. These are generally in very rural areas where the signal is too weak. A professionally installed tall tower, satellite-delivered network stations or lifeline cable is recommended in these cases.
On occasion, some households may find that the recommended antenna type does not provide a suitable picture. This may be due to placement or installation of the antenna, obstacles local to a particular household which interfere with reception, or other issues. While most of these cases can be solved by a suitable directional antenna, there are a few cases where an antenna may not provide workable reception. Distant, outlying areas in very rural locations may not receive a strong enough signal to provide an adequate picture.
Q: Do all TV antennas pick up all TV stations?
A: No, all TV antennas do not pick up all stations. There are several different types of antennas. Which type of antenna is right for you will depend on what signals are available in your area and which ones you want to receive. Antennaweb.org is designed to suggest categories of antennas that will receive the stations predicted for your location.
Q: What does it mean when there is a "-DT", "-LP" or "-CA" after a call sign?
A: "-DT" stands for Digital Television. During the transition from analog to digital TV, stations will broadcast both an analog signal and a digital signal. The station's call sign followed by "-DT" indicates that this is the digital signal for the station.
456棋牌"-LP" stands for Low Power and "-CA" stands for Class A. According to the Federal Communications Commission (FCC) web site, the Low Power Television Service (LPTV) was established by the FCC to provide opportunities for television service for locally-created and community-oriented programming. An LPTV station is limited to broadcasting at an effective radiated power of only 3 kilowatts for VHF channels and 150 kilowatts for UHF channels. LPTV stations MUST NOT cause interference to the reception of existing or future full-service television stations and must accept interference generated by such full-service stations.
Class A stations are a particular type of low power station. Class A licensees will have "primary" status as television broadcasters, thereby gaining a measure of interference protection from full-service television stations, even as those stations convert to a digital format.
Q: What is the importance of antenna in a wireless communication system?
A: Antenna works as transformer, it has two modes of operation as Transmitter and as a Receiver. In transmission mode, the antenna transform the electrical signal guided by the wire or (wave guide) into a propagating free space wave. In reception mode, it does the reverse process, it captures the electromagnetic wave and transform it to electrical signal.
Q: What's best high gain wifi antenna?
A: 456棋牌Some of the most powerful antennas are the 30 dbi grid, and then for even more dbi, the dish antennas are really good. I'm making a homemade wifi dish antenna from an old satellite dish, lots of fun.
Use a low loss cable to connect your antenna and keep it as short as possible. Wifi signals really degrade over cable. For example, if you have 20 feet of cable, you may lose half your antenna dbi just from the cable.
456棋牌If you want to use backtrack, you will need a wifi card that supports monitor mode and packet injection. Look for something with an Atheros chip that is supported by madwifi, and has at least 200mw power.
The cantenna is a directional antenna, so it only works in the direction that it is pointed. Your router antenna is omni-directional antenna, and so it works in all directions. The two have completely different applications.
Q: How Do I Choose the Best Mobile Antenna?
A: A mobile antenna is a type of antenna that generally gives adequate signal even when one is on the road. There are several variables to consider when choosing the best mobile antenna. These variables include the places where you live, where you work, and where you visit regularly, along with your geographical location, and the available frequencies operating in the area. Knowing the various kinds of mobile antennas456棋牌, and how they are mounted can also help you make your choice. Other things to consider are your budget and your technical skills in setting up the antenna.
When choosing a mobile antenna that matches your needs, it is usually advantageous to first determine what kind of environment your antenna will be dealing with. You can try looking around the area surrounding your home, your workplace, and the places you regularly visit. These are places where you will more than likely use your mobile antenna. It is often advisable to take note of the layout of the place and obstructions present in these places. By doing this, you can narrow down your search to a few specific types of antennas.
There are various kinds of mobile antennas. These include the portable ones, the hidden ones, and the mounted ones. If you prefer a hidden antenna, you can choose one that matches your needs. Mounted antennas can be mounted on top of your vehicle, on the glass, or in a movable base. Some mobile antennas work best when they are mounted and reach a considerable height, while others may work well when hidden.
Aside from portability and convenience, you also need to select the mobile antenna that can adapt well with your surroundings wherever you go. An antenna that can change bands and frequencies without requiring too much effort from you is often a good choice, especially when you are looking for a car antenna. A remote-controlled mobile antenna is another one you can select. This is frequently a better choice if you drive around a lot and if you do not have time to stop and re-adjust your antenna in order to change frequencies. A convenient mobile antenna that does not require a lot of maintenance while on the road is generally the best choice.
456棋牌It is also necessary to choose an antenna that matches your budget requirements. Asking more experienced individuals about your specific antenna needs can often guide you in choosing the right antenna that is well within your budget. The installation of your chosen antenna may also require some skills in electronics and in handling different kinds of construction hardware. You can choose to do the installation or you can ask someone with technical skills to do the installation for a certain fee.