Coping with limits
By Michael Grotticelli -- Broadcasting & Cable, 11/25/2001 7:00:00 PM
New York's local stations have relocated transmission facilities at the Empire State Building knowing that they may never replicate their pre-Sept. 11 NTSC coverage. Power levels are limited by the physical foundation that holds the antennas in place, which, in turn, limits a station's ability to reach viewers on the fringe of its coverage area. Questions remain about how to physically locate the analog and digital transmitters and antennas for 12 TV stations and up to 20 analog FM radio stations on a 70-year-old architectural landmark. At the Empire State Building, WNET is using a low-power Lar can transmitter operating at about 10 kW, significantly less than the approximately 50 kW the public station was at on the World Trade Center.
WNET Vice President and Chief Technology Officer Kenneth Devine spoke with B&C about the hurdles involved.
Why did you move from Alpine, N.J.?
We can't cover the five boroughs of New York from Alpine, N.J.; there's very limited coverage into Queens and Brooklyn, which is a big issue since we have a lot of viewers there. We expect to improve our situation by moving, but we do not expect coverage to be anywhere close to what we had. It's the outer coverage that I think will be lagging for quite some time.
Why can't all stations operate on Empire at full power?
The mast on Empire is 200 feet, and it's full. As a practical matter, getting the physical space to put enough antennas to radiate sufficient power for all of the analog and digital channels in New York is questionable at best.
It is possible, but it might involve literally taking the top of the building off and doing serious reinforcement to tie the additional load into the foundation. The Empire State building is an architectural landmark, so that may not be practical. And we'd still have the problem of where everyone would operate from while this construction work is going on.
There is no engineering issue. To get a standard 3 MW UHF station on-air, you need a certain antenna with a huge amount of gain. Currently, there is simply not enough space on Empire to facilitate that.
How will you operate from Empire?
Initially, WNET will locate its transmitter on the 81st floor, with Dielectric panel antennas side-mounted on the corners of the building, giving us omnidirectional coverage. We're also using the transmitter room of WNYE-TV for our transmitter.
As you get further up the mast antenna, power levels can be increased, and signal coverage gets better. We hope to put out about 50 kW once a four-port combiner antenna is installed [sometime next month]. We'll be sharing it with WABC-TV, WWOR(TV) and WPIX-TV, which are all VHF stations operating in the high band. We'll use WABC's antenna, now located at Empire on the former WPLJ-FM aperture on the mast. [WABC-TV and WPIX-TV are currently on-air from there.]
It's important to note that, under any scenario, Empire will remain a part of our facilities, and most stations' in New York, for a long time.
Why can't another tall building be used?
For New York's stations, Empire is the only practical choice. World Trade Center was 1,750 feet; Empire is 1,250 feet, with a 200-foot mast, so it's 350 feet lower. The next-largest building in New York is about 800 feet. Also, the other buildings do not have the structure at the top to support a broadcast tower.
Will insurance cover what you've lost?
It's unlikely. Although everyone is fully insured, I think there's a question about what was covered. The fact that the building fell down was never anticipated by anyone. Our DTV antenna on WTC, which was jointly shared by five stations, cost roughly $400,000, but it cost $8 million to install it there. I don't know that the $8 million is a recoverable item. It's hard to say, but I would imagine that there's going to be some legal wrangling before this is over.
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