HDTV Antennas for Dummies

HDTV antennas

In a perfect world, when someone asks the question "How Do HDTV Antennas Work?" you had better believe that the answer should come from someone who has at least some grounding in the principles of the electromagnetic spectrum and current induction. At the opposite end of the information spectrum, we suspect, would be a liberal arts graduate – say, someone with a degree in "film"; someone like Techwalla.com "walla" Stephen Lilley...

Lilley, who'd already demonstrated his unfamiliarity with broadcast television once before, decided that the OQ clearly didn't need all that physics mumbo-jumbo that he (Steve) didn't understand anyway. As a consequence, Stephen punted. That's right, the closest he came to explaining how an HDTV antenna works was this:

"When a television station broadcasts its programming, it is converted from audio and video information into... electromagnetic signals. The antenna receives the signals..." Yeah, Steve, that's the ticket! The antenna receives them! But wait: the OQ asked, "How do they work?" If you ask us, that means, "How do antennas receive those electromagnetic signals?" Lilley clearly had no idea, so he skipped entirely over that part of the explanation and went directly to, "The main purpose of having an HDTV antenna is to receive broadcasts from local television stations."

Yeah, we got that Steve; but how does it work? Well, it's fairly complicated but the gist of it is that an antenna contains wires that generate a tiny current when exposed to the electromagnetic waves being sent by the broadcast tower. Every tiny current has a frequency; and the "chunks" of current with the correct frequency for the television are selected by the television's tuner; and the rest of the circuitry in the television converts all those currents into instructions that display the pictures and make the sounds. The antenna – HDTV, radio, cell phone, whatever – is constantly exposed to the electromagnetic waves, but is tuned to generate currents only from the correct "size" of wave.
That's what our Dumbass of the Day didn't know, which is probably why Lilley didn't even try to explain the physics behind an antenna. Feh.

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