What's on Top of TV Towers, Anyway?
August 13, 2008 4:24 PM
I came across some interesting information the other day that I thought I would pass on to you.
We’ve all seen the broadcast towers keeping vigilant watch over this great land of ours, with their comforting rhythmic red lights throbbing throughout the night, or the towers that have the pulsating and piercing white strobe lights silently but pointedly announcing their presence.
But have you ever wondered exactly what was on top of those tall and lean sentinels? I had always wondered what the antennas looked like that were mounted on top of these giants.
I gained some insight into that when I was researching KITU-TV and KITU-DT. I found the specifics on a dual adjacent channel antenna that KITU was proposing for its analog and digital broadcast needs. The digital is on channel 33 and the analog is on channel 34.
The antenna is 47.8 feet tall (50.8 feet tall when you include the lightning rods) and has a red warning light on top. It is 16.4 inches in diameter and has an aluminum climbing pole (I presume to change the light bulb. No way! Not me!). It is bolted to the tower with 16 1¼-inch bolts on a 20-inch bolt circle, and it’s painted aviation orange.
The analog transmitter inputs 29.25 kilowatts of power for an ERP (Effective Radiated Power) of 1,170 KW and the digital transmitter inputs 12.5 KW for an ERP of 500 KW. There is an application pending to go to an ERP of 1,000 KW.
But here is the real kicker, and this I would have never guessed: The antenna weighs 8,400 pounds. That’s more than 4 tons of antenna sitting on top of a tower that is rising 1,023 feet above the ground.