Do you have a question about HDTV, digital TV signal broadcasts, or antenna reception? This FAQ file provides the answers to these frequently asked questions about TV antennas.
The cord-cutting phenomenon continues to grow as more people want to be free from expensive cable TV. If you’re planning to cut the cord, you’ll probably have a lot of questions about TV antennas and over-the-air television. To get these answers to you as quickly as possible, we’ve compiled this list of our most frequently asked questions as well as our answers to each. If you need further clarification on any of these answers, or have other questions, feel free to call our product experts at 877.312.4547. We’re always happy to help you better understand TV antennas and cord-cutting.
How can I pick up over the air (OTA) digital and HDTV broadcasts?
There are currently two ways to receive your local stations:
- An over the air only digital receiver that only receives the local channels. These can be purchased at any electronics chain for about $299-$399. One advantage to this is that there will be no monthly fees.
- An HDTV with a built in OTA tuner. You will find that these “integrated” HDTVs cost $300-$600 more than an “HDTV-ready display.”
Are all digital channels on UHF?
No. Currently, 91 percent of broadcasting DTV stations are on UHF. A few cities, such as Chicago and Las Vegas, have DTV stations on VHF and UHF. While many DTV stations are now occupying UHF broadcast channels, the plan might allow some broadcasters to move back to their original VHF or UHF TV channels once the transition to DTV is complete; however, this might not occur for another 10-15 years.
How is reception in distant or “fringe” areas? Will I get a fuzzy picture?
When it comes to digital television, it’s an “all or nothing at all” proposition. Once the signal is acquired, a steady stream of data assures you´ll get a perfect picture and great audio. If that bit stream is interrupted, however, there will be nothing but a blank screen. In areas with lots of buildings or obstacles, multi-path distortion can cause a “cliff effect” to kick in. The fix is to use a higher-gain antenna assuming the multi-path can be tamed. Work is being done to determine the optimal designs for improving error correction in set-top receivers.
How do analog TV broadcasts and DTV compare to each other?
There are some similarities. Both use VHF and UHF broadcast frequencies. While analog and digital television broadcasts have a modulated carrier wave, the way that signal is modulated is entirely different. Analog TV uses an amplitude-modulated (AM) signal for pictures, and frequency modulation (FM) for audio. DTV signals use digital “packets” to transmit pictures and audio. The modulation system currently being used for DTV in the U.S. is eight level vestigial sideband (8VSB). As terrestrial digital/HDTV broadcasts become more prominent, UHF antennas will play a larger role because the majority of the HDTV/digital channel allocations will be in the UHF frequency band.
What cities have digital VHF Stations?
One potential problem with re-using low VHF (2-6) and high VHF (7-13) TV channels for DTV is the possibility of interference from other signals during certain times of the year. “Skip” might bring in distant broadcasts on the same channel and create interference. The physical size of low VHF and high VHF antennas is much larger than that of a UHF antenna. DTV broadcasts use the same channels (frequencies) as regular analog television.
What is a Yagi?
Although not the original inventor, the Yagi antenna is credited to Hidetsugu Yagi, A Japanese physicist. The Yagi antenna was designed to improve the gain of the antenna concentrated in one direction. The directivity is accomplished with added elements called directors and reflectors. The Yagi has high gain, is very directional, and has narrow bandwidth. In simple unidirectional antennas such as the Yagi, frequency bandwidth is inversely proportional to antenna gain. One way to increase the frequency bandwidth of a simple antenna, such as a Yagi, is to increase the diameter of the antenna conductors. The greater the conductor diameter, the wider the band. Increased conductor diameter also has a second benefit, which is that it increases the physical strength of the antennas.
What is the difference between UHF and VHF antennas?
The most obvious difference between VHF and UHF antennas is the size. A half wave dipole for channel 2 will be 10 times longer than for channel 28. This means that a much more elaborate UHF antenna can be constructed without the antenna becoming physically unmanageable. With more elements added to the UHF antenna, higher gain and directivity can be obtained.
What is a bow tie antenna?
A bow tie antenna is another name for a UHF fan dipole antenna. By using triangular elements instead of rods, the bandwidth is greatly increased, to cover the entire UHF band. Additionally, the mesh reflector of the bowtie is more efficient than the rod reflector as it is lower in weight and has less wind resistance.
What is a corner reflector Yagi?
A corner reflector is a popular UHF reflector that has a very high front-to-back pickup ratio for reducing reception from the backside. This is particularly important if you don’t want interference from stations to the rear of the antenna. The driven element is placed at the center of the corner angle that affects the power gain, directivity, and impedance. Combined with Yagi type directors, this increases the gain and directivity of UHF antennas over the entire UHF band.
My wife won't let me put one of these things on my roof. Can I install an antenna in my attic?
Yes you can. Just keep in mind that one layer of asphalt shingles + roof felt + 3/4" plywood roof deck = 50 percent reduction in signal strength. Plus, if you have metal- or aluminum-backed insulation in the walls or under the roof, the signal most likely will be blocked. You´ll have to remove the insulation or install the antenna in a different place. Also, you´ll still need to make sure that the narrow end points toward the transmitter of the TV station.
My Homeowners association prohibits antennas on the roof. What can I do?
Show them the Federal law concerning antennas, homeowners, and their rights. In 1996, The FCC affirmed the rights of homeowners to place antennas on property they own or control. (Masts higher than 12 feet above the roofline may be subject to local permitting requirements.) The law basically states that homeowners association covenants cannot prevent you from installing antennas or dishes. The rule “prohibits restrictions that impair the installation, maintenance, or use of antennas used to receive video programming.”
How far can I be from the transmitters and still get a good signal?
Getting reliable UHF DTV reception beyond the curvature of the earth (approximately 70 miles) is difficult. The good news is that terrain has a major impact on reception. Going over water is about the best it gets, since water is generally flat and has positive impacts on temperature for sending the signal along. Still, beyond 70 miles – unless you can get direct line-of-sight to the transmitters – the number of things that can negatively impact reception are numerous. Just keep this in mind and be prepared to accept that what you want might not be possible.
I have read ads for a TV antenna that can pick up stations 200 miles away. Is this possible?
Under extremely rare circumstances, a TV antenna could possibly pick up stations 200 miles away. However, rarely is an antenna going to get terrestrial television broadcasts over such a distance. Theoretically, it would be possible if you lived on top of a mountain and the broadcast towers were also on a mountain. At normal elevations, however, the curvature of the earth limits effectiveness to about 70 miles for UHF band signals. Low VHF band (2-6) can bounce further than this; but currently, only about 7 percent of digital TV channels are on the VHF band. Most digital TV channels are on the UHF band, which is line-of-sight transmission.
What about HDTV antennas sold at the electronic chain stores? Won't these work?
Maybe, but often times, these antennas are no better than a coat hanger. Very few antennas sold in these electronic chain stores have much success with digital reception. They usually have poor gain on the frequencies where digital broadcasts occur and have a difficult time with multi-path distortion. Most utilize low-grade amplifiers that introduce noise on the line or are shaped to be aesthetically pleasing but are contrary to the principals of digital TV reception.