Broadcasters Pull Together

CBS helps five New York stations return to DTV broadcasts

For the first time since 9/11, five New York City broadcasters will begin full-power, over-the-air DTV broadcasts. That’s thanks to CBS, which is letting competitive stations transmit their signals through its Empire State Building antenna.

WABC, WNBC, WWOR, WPIX and WNET lost their DTV facilities when the World Trade Center was destroyed. With available real estate atop the Empire State Building and WCBS willing to grant access to its DTV antenna, the stations decided it was a logical place to build DTV facilities.

“The [new facility] is a tribute to the engineering and construction crews that have worked overnight 1,300 feet above the ground for two years,” says Dave Davis, WABC New York general manager. “Lawyers arguing in a room is one thing, but the credit really goes to the engineers.”

Indeed, this massive DTV project has been in the works more than two years.

The key physical complements are two signal combiners from Dielectric. The six transmission signals are fed into the combiner on the 85th floor, filtered, then output to the antenna and subsequently to viewers.

Getting the combiner in place was only one of many issues that had to be addressed. A radio transmitter for a small FM station had to be moved down the hall, a process that proved more difficult than initially believed. Then the negotiations with the building for transmitter space—as well as preparing the upper floors with backup power, electric and fire suppression—took additional time. Finally, to seal the deal, all stations had to agree to vote on how they would handle potential conflicts, such as interference or when to switch to the backup system.

“In general, it hasn’t been technology issues that have been the long-lead items,” says Bob Seidel, CBS vice president, engineering technology, who headed up the project. “It’s been negotiations, agreements and lawyers that have affected our pacing.”

The groundwork for the system was actually laid in 1997, when WCBS was putting its DTV antenna in place. After consideration, it decided to put a multi-purpose antenna in place so it could operate different frequencies from one antenna.

“Since we knew we were going to be a very early adopter of DTV in New York, it made sense to put one up that would be broadband-capable,” says Bob Ross, CBS senior vice president, East Coast Operations. “We also knew it wouldn’t be easy to erect the antenna. This way, we could put it up once and use it forever.”

A big boost to WCBS was that it already had a five-bay antenna in place at the Empire State Building. That one was taken down and replaced with a two-bay antenna, freeing up three bays for the multichannel UHF antenna that is now home to the majority of New York’s DTV signals.

Work, however, didn’t begin until the stations sorted out their analog-transmission problems following 9/11. WABC, for example, has an analog and digital transmitter located at 4 Times Square. Those transmitters will now serve as backup; WABC will move its primary analog transmission to the Empire State Building. WABC’s system, like those of the other four broadcasters, was less than ideal in terms of market coverage. That left the stations open to WCBS’ proposal to share antenna space.

“The answer came back yes, and that was the beginning of a pretty long series of negotiations with Empire and [the stations],” says Ross. Deals were struck, with costs split equally among the six stations.

This week, low-power tests will measure performance and ensure that the antenna can handle the move to high power. The week of Dec. 13, the facility will be up and running to accommodate some high-power testing, although not all stations have finished installation of their transmitters. Davis says WABC will be at full power by the end of the year. “For the first time since 9/11, we’ll be able to broadcast at our full licensed power.”

The end of the project actually has ramifications outside of New York.

Throughout the project, WCBS(DT) signed off at midnight to accommodate workers. The problem: WCBS(DT) is used by DirecTV to serve the entire nation. “At midnight, the country goes dark. Once the work is completed,” says Seidel, “we’ll be 24/7.”