Frequently Asked Questions
Q: What is O-T-A television and how does it work?
A: Over-the-air television is a term used to describe television signals that are broadcast by your local television broadcast towers (as opposed to a cable or satellite signal). Since 2007, these signals are broadcast using digital signals, as opposed to the analog signals, which were in use prior to 2009. There are currently 3 ways to pick up your local stations:
Q: Are all Digital Channels on UHF?
A: No, not all channels are on UHF. While Many DTV stations are occupying UHF broadcast channels, there are many stations providing VHF broadcast channels as well. For more information, please visit www.antennapoint.com.
Q: How is reception in distant or "fringe" areas? Will I get a fuzzy picture?
A: 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 - just 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.
As far as distance is concerned, getting reliable UHF DTV reception beyond the curvature of the earth (approximately 70 miles) is difficult. Terrain has a major impact on reception. Going over water is the best-case-scenario since water is generally flat and has positive impacts on temperature for sending the signal along. That being said, beyond 70 miles, unless you can get direct line-of-sight to the transmitters, obstacles which impact reception negatively are inevitable.
Q: Getting VHF stations is a problem for me. I get everything else fine.
A: Many stations that have reverted to VHF assignments have dramatically cut their transmitter power, in some cases by over 90%! Some stations mistakenly thought they could save money by cutting their power while reaching the same number of viewers. In other cases the FCC imposed reduced power limits to stations that reverted to their old VHF assignments in order to prevent interference with adjacent markets. There has been a misperception among some station owners that while dramatically lowering DTV transmitter power, they could serve the same coverage area as analog, and this has turned out to be incorrect. Many stations who have reverted back to VHF are now finding themselves with significantly reduced coverage areas and fewer viewers after switching to VHF.
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" may bring in distant broadcasts on the same channel and create interference. Low VHF (2-6) digital broadcasts are particularly prone to interference and are often hard to receive reliably, regardless of what model of antenna is used. Note: The physical size of low VHF and high VHF antennas is much larger than that of a UHF antenna.
Q: What is a Yagi?
A: The Yagi antenna is credited to Hidetsugu Yagi (although not the original inventor), A Japanese physicist. The Yagi 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 like the Yagi, frequency bandwidth is inversely proportional to antenna gain. One way to increase the frequency bandwidth of a simple antenna like a Yagi, is to increase the diameter of the antenna conductors. The greater the conductor diameter, the wider the band with increased conductor diameter also has a second benefit, it increases the physical strength of the antennas.
Q: What is the difference between UHF and VHF antennas?
A: 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.
Q: What is a Bow tie Antenna?
A: 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. It is also lighter in weight and has less wind resistance.
Q: What makes a ClearStream™ antenna different from other antennas?
A: Whenever you design an antenna for a narrower range of frequencies, you can expect dramatic improvements in performance. Our ClearStream™ series of antennas are tuned specifically for the core DTV channels. ClearStream™ antennas are also less prone to interference and will ensure the best signal reception.
Q: Can I install an antenna in the attic?
A: Sometimes, for various reasons, it is necessary to install your antenna in the attic. However, keep in mind that one layer of asphalt shingles + roof felt + ¾" plywood roof deck = at least a 50% reduction in signal strength. Plus, if you have metal or aluminum-backed insulation in the walls or under the roof, the signal will most likely be blocked. You'll have to remove the insulation or install the antenna in a different place. In addition, although the antenna is inside, you'll still need to make sure that your antenna is pointing toward your local TV broadcast towers. Visit antennapoint.com to find your nearest towers, and visit our page Attic Installation Tips for more information.
Q: My Homeowners association prohibits antennas on the roof, what can I do?
A: In 1996, The FCC affirmed the rights of homeowners to place antennas on property they own or control.* You can read the FCC ruling here: http://www.fcc.gov/mb/facts/otard.html*. The law basically states that homeowner 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."
*Masts higher than 12 feet above the roofline may be subject to local permitting requirements.
Q: I have read ads for an antenna that can pick up stations 200 miles away. Is this possible?
A: Under extremely rare circumstances, a television antenna could possibly pick up stations 200 miles away. However, an antenna is only very rarely 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 pretty much 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% of digital TV channels are on the VHF band. Most Digital TV channels are on the UHF band - which is line-of-sight transmission.
Q: My channels display as 2.1, 5.1, 7.1 etc. So I need a VHF antenna, right?
A: Digital channels are a method of transmitting more than one independent program stream simultaneously from the same digital television station on the same frequency channel. The practice is sometimes called "multicasting", thereby using the second digit to support multiple program streams over-the-air. This allows TV stations to transmit one or more subchannels over a single digital signal.