TechMan, being a geek, is always excited when new tech toys come on the market.

Such a thing is happening, as digital-to-analog converter boxes are showing up in stores in advance of the switchover to all digital broadcast TV in 2009.

If you're regular reader, you know we've talked before about the switchover (Go to post-gazette.com/techman and find the article from Jan. 19 in the archive section.)

Let's get some facts out on the table. You need one of these boxes if your TV does not have a digital tuner (sometimes called an ATSC tuner) and you get your television reception through rabbit ears or a roof or mast antenna. If this describes you and you don't have a box, starting Feb. 17, 2009, your TV will get nada, nothing, snow.

If you have cable, satellite or FiOS TV, or a TV, DVR or TiVo with a digital tuner, you don't need to buy anything.

Check carefully. If your set says "digital monitor" or "digital ready" or "HDTV ready," it does not necessarily have a digital tuner. It should say somewhere that it has a digital tuner.

For those without digital tuners, the converter boxes cost between $40 and $70 for basic models.

Out of the goodness of its heart, Congress has approved up to two $40 coupons for each household for as long as the money appropriated lasts.

These are not rebate coupons. You must have them in your hot little hands when you buy the converter(s). It is illegal to sell or transfer them to someone else.

To get a coupon go to www.dtv2009.gov or call 1-888-388-2009. The coupons expire 90 days after issue.

What you get when you buy a basic box is a digital tuner to replace the analog tuner on your TV. That means one television per box. The converter will probably have a remote and onscreen menu. Fancier (and more expensive) models may include the ability to record digital TV.

A digital converter box will not give you digital cable channels or any other cable channels. It is still picking signals out of the air, only now they are digital signals.

Finally, I come to the point of this column: How you can convince a skeptical spouse that you need to spend $20 (with coupon) for this toy even if you have cable.

If you have analog TVs in your house that are not hooked up to the cable for whatever reason (you didn't want to drill holes or you were too lazy), you will probably need a converter box.

Ditto for the little TV without cable in your deer camp cabin or summer cottage or RV.

There is no reason to delay. Most TV stations are broadcasting in digital right now. The picture is better and you can get subchannels, additional channels from the same station. One local station for example, is using a subchannel to show TV from the 1950s and succeeding decades.

But you may need to improve your antenna. Some studies have shown areas that are hilly (can you say Western Pennsylvania?) may have problems getting digital signals.

An excellent source of info on all this is www.dtv2009.gov.

So don't wait until the last minute. You don't want some poor sucker (like you) crawling on your roof on Feb. 16, 2009, trying to put up an antenna during an ice storm.