EDN Writer Tries Off-Air DTV – Part Two

By Doug Lung
published

Electric Design News (EDN) senior technical editor Brian Dipert continued his tale of off-air TV reception in postings last Friday and this Thursday. Last week Jack Antonio, chief engineer at Reno, Nev. Station KTVN, along with his assistant, Eric Brown, visited Dipert, who was having trouble receiving the station, even though he was able to receive other stations on Slide Mountain, outside Reno.

It turned out the cable in his house was attenuating the high VHF DTV signals by 8 dB. After reviewing the specifications, the engineers confirmed that the Clearstream 2 antenna from Antennas Direct was a UHF-only antenna. Dipert asked Antennas Direct Founder and President Richard Schneider to explain the company’s claim of “consistent gain” through the entire DTV channel spectrum. Schneider responded that designing an antenna that would cover both bands without compromising UHF reception turned out to be harder than expected. The solution they came up with was to redesign the antenna balun to allow the feed line to act as a high-band VHF antenna. The ClearStream 5, a high-band VHF only antenna, is recommended for viewers in fringe areas with high-band VHF reception problems.

In my RF Technology column in the Sept. 3 issue of TV Technology magazine, I’ll look at spectrum usage after Feb. 17, 2009. One quarter of all U.S. TV stations will then be using VHF channels.

See Brian Dipert’s Thin-Air ATSC (And NTSC): An Engineer Visit and An Antenna Reposit for the full story. Also see Thin-Air ATSC (And NTSC): The De-Boost (or Over-Boost) Debacle describing Dipert’s experiences with TV preamplifiers.

Doug Lung
Doug Lung

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.