Digital /HD over the air (OTA) reception is not much different than the analog signal we have been using for over 50 years to receive TV, with a few exceptions. As an installer, I would like to share with you my experiences thus far.
To receive OTA digital signal you must have a digital tuner. The tuner can be built into the TV or stand alone as a set top box. The stand - alone digital tuner can provide true HDTV signal to HD monitors, or they can convert received digital signal into analog and provide signal for your current non-HDTV set.
Many times a simple indoor antenna can provide excellent digital/HD reception. Other times a more elaborate outdoor antenna system is required, either way it’s worth it. The type of antenna you choose will be dependent upon your location and the surrounding terrain.
If your current TV antenna provides good analog reception, chances are very good, it will provide excellent digital/HD reception results, with few exceptions. OTA Digital signal is an all or nothing proposition, you won't see double images or snow, and it will come in perfect. On the other hand if the signal is poor it may not come in at all, and that can be where some frustration can begin, if the proper TV antenna is not selected.
In many ways the only difference between digital/HD and analog reception is the tuner itself. Digital and analog signals are both sent from broadcast towers to a receiving antenna. The biggest difference is what each signal is carrying. The digital signal carries data, while the analog signal carries radio waves. Mixed in with each signal is interference. The analog tuner can’t tell the difference between TV signal and interference so it provides both to the TV, possibly resulting into what is called snow or double imaging. On the other hand, the digital tuner receives data that it can separate from interference delivering a near perfect picture to your TV. However, if too much interference is accompanying the digital signal, the tuner may not be able to clearly read the data being sent and you may loose the signal altogether, leaving you with a blank screen.
Digital OTA reception is free to the air, signals anyone can receive at most locations in the United States, using the proper equipment. The antenna and equipment you choose, along with employing the proper installation methods, can play a big role in determining your reception results. The biggest mistake people can make is to choose the antenna they want to work and not the one that will work. Everyone wants the smaller, simpler more compact antenna to work and many times it will. Do your homework, determine the distance and direction of the TV stations you want to receive. Examine your surrounding terrain for a couple of miles in the direction of the TV stations, for hills, dense trees or structures that can obstruct TV signal. Consider the elevation you can install the antenna at and the elevation of the ground itself at your location.
Besides transmitter distances and terrain, the actual channel frequencies the local broadcasters use to transmit the signal to you will determine the type of antenna you will need. There are basically 3 types of antennas, VHF antennas for channels 2 through 13, UHF antennas for channels 14 through 69 and combination VHF/UHF antennas designed for all channels from 2 through 69. To the best of my knowledge there are no locations in the U.S. that are or will broadcast all of the local digital channels on VHF. Some locations are and will continue to broadcast all of the local channels on UHF. Most locations however are or will broadcast on both VHF and UHF.
In a nutshell, to receive over the air digital TV, you must have a digital tuner. Either a set top digital tuner or a tuner that’s built into your TV. When choosing your antenna and equipment. Always consider distance and direction of the stations. Examine the terrain for possible signal obstructions. Evaluate the elevation where the TV antenna is to be installed. Determine what channel frequencies your local broadcaster will use to transmit the signal, now and after the digital transition is complete in 2009 and choose the antenna and equipment accordingly.
Denny Duplessis the author of Understanding OVER THE AIR digital/HD TV Reception and
can be contacted at dithaca@msn.com or you may visit his website
TV Antenna Source at http://www.dennysantennaservice.com
The article Understanding OVER THE AIR digital/HD Reception is the property of the author and TV Antenna Source and can not be reprinted or republished for any reason without the written permission of the author.
©2006 TV Antenna Source
