Tech Corner: Improving digital TV reception

The time has come. You can put it off no longer. The switch-over to digital TV is well underway and the clock is ticking on that relic of the 20th Century – analog.

You’ve been hearing the rhetoric around digital TV for years now. Perfect picture, every time. No more ghosting, static, or rolling. All your reception problems, fixed with the purchase of a TV with a digital tuner, or a digital set-top box.

Well, of course it’s not quite that simple. The digital TV signal uses the electro-magnetic spectrum, just like analog. And that means that unlike when regional UHF broadcasts began in the late 1980s, you don’t need a new antenna to receive digital.

But your antenna does need to receive a quality signal to give you reliable, problem-free digital TV. And that can get a bit tricky.

Reception problems

On an analog station, you can tell very easily when you’re not receiving a perfect signal: you’ll see all those artefacts we’ve long accepted, and which digital TV is supposed to cure. Ghosting, caused by the signal bouncing off terrain. Static and snow. “Move it a little bit to the right, darl!” was the catch-cry of the self-installer, and tweaking would improve the signal to the best ability of your antenna and physical location.

Thing is, digital TV can suffer from the same signal quality problems, but you don’t immediately see it as you watch. Digital TV, by definition, either works or it doesn’t. You either receive a perfect picture, or no picture at all.

Well, that’s not quite true. What you get is perfect image and sound for a few seconds, then everything breaks up into squares, like a dirty DVD. What’s most irritating about this is that a broken digital TV signal is completely unwatchable, unlike a poor analog signal which might have a ghosty image, but perfectly serviceable sound – Australia might field 22 men, but at least you won’t miss the score.