Some digital VHF stations are cutting power up to 95%
June 8, 2009; ST. LOUIS - While people may know that 24% of DTV stations are reverting back to their original VHF channel assignments, few are prepared for the dramatic power reduction for some of these stations, resulting in millions of Americans losing DTV reception. To meet the demand for reliable digital reception, Antennas Direct created the ClearStream 5, a powerful antenna for low -power, high VHF DTV channels; channels 7 to 13.
"For years, there have been warnings about the problems with DTV broadcasting on the VHF band; lower fractional bandwidth, increased interference from noise and adjacent markets, and the reluctance of customers to install significantly larger, performance -compromised combo UHF/VHF antennas," said Richard Schneider, president of Antennas Direct. "But now things have become even worse because some VHF stations have cut their ERP (effective radiated power) by 95%, making reception nearly impossible. With all these factors at play, we predict that a huge percentage of the country will lose VHF DTV reception."
In fact, widespread VHF signal loss was the reason Louisiana Media Co. recently decided to revert back to it UHF DTV channel assignment. The media company petitioned the FCC to restore WVUE Fox's UHF digital channel 29 assignment and terminate its VHF channel 8 assignment in order to reach the "significant number of viewers" who reported complete signal loss while the station was transmitting on the VHF band.
"Typically, VHF frequencies propagate better than UHF signals, but the reduction of ERP on the VHF band in some cases is so sever, the channel becomes nearly unwatchable," Schneider said. "We've designed the ClearStream 5 with the highest possible gain for channels 7 to 13 to offer consumers the best chance for receiving high VHF DTV in those low -powered markets."
"The assumption was that ATSC (digital) broadcasting can be 10 times more efficient than analog, that transmitter power could be cut, electric bills would be slashed and the station could maintain the same coverage area, but that's not how it ended up," he said, "Yes, digital does offer efficiencies, but not nearly enough to make up for the dramatic reduction in transmitting power that we're seeing across the country."
While viewers wait to see if the estimated 400 VHF DTV broadcasters decide to increase power or move to the UHF band, Antennas Direct will be shipping the Clearstream 5 high -band VHF antenna to afford them higher reception rates. The C5 will be the most powerful compact VHF antenna ever offered, with a nearly uniform gain of 8.4 dBi for high VHF channels 7 -13. Also, the efficiency of the ClearStream 5 allows a significant majority of the available broadcast signal to reach the incoming antenna cable without being lost to impedance mismatches.
Antennas Direct designed the 28 -by -23 -inch square loop antenna to be 80% smaller than typical VHF antennas, which can have a width of over 100 inches. Its small size makes the C5 easier to install as a supplement to UHF antennas. Each ClearStream 5 comes with a low -loss UHF/VHF signal combiner.
The ClearStream 5 has a reception range of up to 65 -plus miles and will retail for $119. It will ship late June.
Range: 65 + miles.
Design: Square Loop with Tuning Bar
Size: 23"w x 23"h x 11.5"d
Target: High VHF Channels 7 -13 (174 MHz - - 216 MHz).
Typical Gain: 8.4 dBi.
Beam Width: 70 degrees
Antennas Direct is a St. Louis -based manufacturer of over -the -air antennas specifically tuned for core DTV frequencies. Its ClearStream antenna series has been widely recognized by broadcast engineers and industry publications for its superior design and performance for DTV. Antennas Direct, a 2008 Inc. 500 fastest -growing company, has invested major resources into the discovery and implementation of new antenna technology and continues to test and modify antenna designs, raising the bar by which antenna performance and appearance are measured. Visit www.antennasdirect.com for more information.