By Kim Hart
Washington Post Staff Writer
Wednesday, June 17, 2009
Five days after the national transition to all-digital television, WUSA, the area's CBS affiliate (Channel 9), and WJLA, the ABC affiliate (Channel 7), have disappeared from screens around the region.
The stations were the only two in the Washington area to move their digital signals from UHF to the VHF frequencies they once used for their analog broadcasts. That has left thousands of viewers like Steve LaRochelle, of Silver Spring, without access to "CSI" and "Oprah."
LaRochelle received the stations perfectly before the digital transition on Friday, when all full-power stations permanently turned off their analog signals.
But now, "they don't even register after a rescan," he said, although he is able to receive Baltimore's ABC channel.
Bill Lord, vice president of news at WJLA in Arlington, said the station has received more than 350 calls from viewers who are having reception problems since Friday's transition. It is holding an online chat at noon today on WJLA.com to answer questions. WUSA could not be reached for comment.
The sudden loss may be due to viewers trying to capture VHF signals with a UHF antenna.
LaRochelle said he bought an antenna a couple of years ago after upgrading to a digital TV, but he didn't realize it was a UHF antenna. "Nor did I realize WJLA and WUSA were going to be switching back to a VHF signal," he said.
To receive all the available digital stations, consumers should install an antenna that can receive both UHF and VHF broadcasts. Indoor antennas should have extendable poles, or "rabbit ears" for VHF reception and a loop for UHF.
"Even then it requires some moving around from place to place in your house to get the signal right," Lord said. "We've told people quite often that they have to rescan their converter boxes two or three times to lock in the station."
The Federal Communications Commission is looking into reports of lost stations in several markets, including Chicago and Philadelphia. In some cases, stations may have to increase power levels or add translators to extend the signal to more viewers. About 20 percent of the calls to the agency's DTV hotline were from viewers who had lost at least one station.
More than 480 stations across the country are now airing broadcasts on VHF stations, FCC spokesman Mark Wigfield said, and 216 stations were operating on those frequencies before the transition. WJLA, for example, was broadcasting its analog signal on Channel 7 and its digital station on Channel 39 before the transition. (Viewers should not have noticed the change.) When it turned off its analog signal, it moved its digital signal to the Channel 7 slot in the VHF band of frequencies.
As a result, some digital tuners and converter boxes are still trying to pick up programs on the old digital station. Wigfield suggests trying a "double rescan," which involves unplugging the antenna from the converter box or TV, rescanning, turning off the box or TV, then turning it back on, plugging the antenna back in and rescanning once more. The process should clear the tuner's memory so it can locate the digital frequency.
But it may not clear up all reception issues for consumers. After performing a "double rescan," LaRochelle said he was able to pick up Channels 7 and 9, but only at weak signal strength.
In general, VHF signals travel further and more efficiently over hilly terrain. UHF signals often travel better in cities because they are less sensitive to interference, the FCC said.
Michael Young, an electrical engineer and George Mason University professor, said the "double rescan" method will force TV sets to pick up every signal within range. But he acknowledges the complexity of getting adequate reception.
"This even confuses me, and I'm a radio expert," he said.