DTV Reception 35 Miles From the Transmitter—Does it Work?
After I mentioned readers’ response to the question raised by the Centris study on DTV reception—does it work over 35 miles?—I’ve received even more e-mail messages with evidence supporting both yes and no answers.
Responses covered reception in markets from Boston to Los Angeles and even included a report on DTV reception from a reader with a travel trailer who used an antenna mounted on a 13-foot mast. Many of the readers commenting on reception used tower-mounted large antennas with preamplifiers.
Not all were successful in receiving DTV. One reader in Livingston, Texas, has a 65-foot tower and is able to receive more than 25 analog TV stations, but has had no success receiving DTV.
The most common UHF antenna was an eight-bay bowtie, often used with a Channel Master CM7777 or CM7775 preamplifier, although fair number of responders used dual VHF-UHF antennas. Some readers reported they were able to get some distant analog reception on indoor antennas, but didn’t have any success picking up DTV stations beyond 35 miles with small indoor antennas. In some cases attic-mounted antennas with a preamplifier provided DTV reception over greater distances.
There weren’t enough reports of VHF DTV reception to draw any conclusions, except that viewers outside Chicago were often able to get decent UHF reception, but were unable to get solid reception of low-band VHF DTV on Channel 3 from Chicago. An engineer at WBRE-TV (Wilkes-Barre, Pa.) said that he had reports of good reception of DTV Channels 11 and 13 from viewers more than 60 miles away, and that rabbit ears worked out to about 25 miles.
Readers in the areas around Washington, D.C., enjoyed excellent DTV from stations more than 35 miles away. One reader in Vienna, Va., said that while his neighbor’s trees blocked reception of Washington’s WJLA-DT and WUSA-DT, he was able to receive the same network programming from affiliates in Baltimore.
Another reader in Charlestown, W.V.. reported he was able to receive all the Washington (60 miles distant) and Baltimore (70 miles distant) stations at his house, which is located in a valley. He used two stacked 8-bay bowtie antennas up 25 feet and a preamplifier to achieve this. While the UHF DTV reception was solid, UHF analog reception was unwatchable due to multipath and noise.
Some of the reports commented on how tricky it could be to get solid DTV reception. One commenter, a broadcast engineer living in northern California, said he was able to get acceptable reception of VHF analog signals, but found UHF DTV signals could drop out for up to 15 minutes. Others commented on a how a small change in antenna orientation could make the difference between solid reception and no reception.
In my opinion, all the readers responding to my question had more experience with TV reception than the average viewer. As noted, most were using outdoor antennas and most had preamplifiers. While urban viewers are likely to experience great results with indoor antennas, analog TV viewers in rural areas may have problems if their antennas aren’t aimed correctly or if signal levels are low.
One concern is that the average over-the-air TV viewer with a marginal, but acceptable, analog signal will find their DTV converter box works perfectly some of the time, but that the picture can disappear without warning. When I switched Telemundo Network’s satellite distribution from analog to digital in the early ‘90s, a common complaint from operators at small cable systems was that after they had hooked the digital satellite receiver up to their small satellite dish and were amazed at the excellent picture they received, the signal disappeared the next day! They felt the problem had to be at the uplink, as they had a perfect picture one day, and then nothing the next. “Smart” antennas should help with DTV reception, but the models I’ve seen were not designed for reception in weak signal areas near the edge of a station’s coverage area.
As broadcasters, one thing we can do to help is educate viewers that reliable reception requires a little more work to achieve reliable reception than analog TV. Rural viewers should know they will likely require a preamplifier and for reception of UHF DTV stations may have to install a new and larger DTV antenna. Consumer electronics manufacturers can help by designing “smart” antennas for weak signal areas. Finally, DTV sets and converter boxes must have easy-to-use displays for adjusting antennas for the best reception. I like the approach AutumnWave took with the software for its USB DTV tuners—audio beeps that indicate when the antenna is peaked.
Is DTV reception possible more than 35 miles from the transmitter site?
Is it easy?
Probably not, especially at distances of 60 miles or more, unless a high-gain antenna and preamplifier are used. The good news is that many viewers are likely to live within 35 miles of the transmitter site and will be able to use indoor antennas, especially “smart” antennas, to achieve reliable DTV reception.
The consumer reviews on Walmart’s Web site for the Magnavox DTV converter box indicate that many viewers are having no problems making the switch to DTV and were, as I expected, amazed at the picture quality. Review headings include: “Amazing Experience,” “Good Picture,” “Clear Picture and Sound” and “Great Product.”
Not all were successful—one reviewer wasn’t able to receive the same number of channels on the Magnavox he was had with his DVR and returned the box. Another said that out of the nine broadcast stations in his area, he was only able to receive two and they weren’t ones he watched. Negative comments, for the most part, focused on the limited features, device problems (bad audio on the RF out) and overheating that were unrelated to DTV reception.
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Doug Lung is one of America's foremost authorities on broadcast RF technology. As vice president of Broadcast Technology for NBCUniversal Local, H. Douglas Lung leads NBC and Telemundo-owned stations’ RF and transmission affairs, including microwave, radars, satellite uplinks, and FCC technical filings. Beginning his career in 1976 at KSCI in Los Angeles, Lung has nearly 50 years of experience in broadcast television engineering. Beginning in 1985, he led the engineering department for what was to become the Telemundo network and station group, assisting in the design, construction and installation of the company’s broadcast and cable facilities. Other projects include work on the launch of Hawaii’s first UHF TV station, the rollout and testing of the ATSC mobile-handheld standard, and software development related to the incentive auction TV spectrum repack.
A longtime columnist for TV Technology, Doug is also a regular contributor to IEEE Broadcast Technology. He is the recipient of the 2023 NAB Television Engineering Award. He also received a Tech Leadership Award from TV Tech publisher Future plc in 2021 and is a member of the IEEE Broadcast Technology Society and the Society of Broadcast Engineers.