07:26 PM PDT on Friday, April 28, 2006

By ROBERT MAK / KING 5 News

In just a little more than two years, the federal government is taking away the TV channels we've used for decades.

On February 17, 2009, your old TV set won't be able to get any signal over the air.

The switch to HDTV has millions of Americans buying new sets already. Here's the basics on what's available.

We asked Hans Brackmann at Magnolia Audio-Video to lay out our choices.

Brackmann started by showing us the rear projection TV sets that sit on the floor.

They look bulky and heavy, but the technology has come a long way. They're very light.

"Yeah, there's not much to it," Brackmann said.

Many of them use LCD - liquid crystal displays - the same technology you see in computer laptops.

The image is projected from the back.

"You have basically, your light source, and your LCD panel back here, it will reflect off a mirror, which is probably right back through here that will reflect it up on to the screen," Brackmann said, gesturing at the TV.

The downside of projection LCD's is that they're not as bright or as clear if you view them from an angle.

Another kind of projection TV is called DLP. It's a semiconductor with two-million microscopic mirrors.

Some complain these DLP screens can have a very slight rainbow effect, but others insist the picture is better.

"So our blacks are going to be blacker, our whites will be whiter, so we get a more even spectrum of color if you will," he said.

If you're still not sold on a projection TV, your other option is the flat-screen. It's more expensive, but it's thin enough you can hang it on the wall.

There is no mirror and there is no projection. It's just a panel.

In the world of flat panels, there are even more choices to make.

The smaller ones tend to be LCD. As you get larger than 42 inches, you see more plasma screens. They're heavier and they use more power, but their contrast is richer.

"So what we get is a lot more color intensity to it, it has a lot more brightness overall," Brackmann said.

Before getting too far Let's recap.

There are two major types of HDTV sets. In the category of rear projection, there's liquid crystal technology VS. the DLP chip.

Both are similar in price. It's really which one looks better to you.

In flat-screen TV's you have LCD's and plasma sets, which start around $1,500.

Another option, for under $1,000, is to get an HDTV set with an old-fashioned tube inside.

But they're heavy and being phased out.

Yet another option, is the front projector if you've got the room and a big screen.

The prices of HDTV sets have been dropping dramatically.

Experts predict prices will continue to fall as the 2009 deadline approaches and manufacturers battle for your business.

Editor's note: Robert will take an in-depth look at HDTV this weekend on KING 5 News Up Front, Sunday at 4:30 p.m. on KING and 10:30 p.m. on KONG 6/16.