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March 2008
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Digital TV converter boxes: First Look
Previews of the Magnavox TB100MW9, Insignia NS-DXA1, and Zenith DTT900

Magnavox TB100MW9
Magnavox TB100MW9
With the digital TV transition less than a year away, digital-to-analog converters have started showing up in retail stores. These set-top boxes convert digital transmissions pulled in by an antenna into analog signals that can be accepted by an older tube TV and other display sets that don't have a built-in digital tuner. Such TVs must be hooked up to one of these boxes to continue receiving free over-the-air TV after Feb. 17, 2009, when U.S. broadcasters must discontinue analog transmissions and broadcast only digital signals.

You can find more helpful advice on our DTV-related posts on our Electronics Blog.

We tested three of the first digital-to-analog converters to hit the market: the Magnavox TB100MW9 ($50 at Wal-mart), Insignia NS-DXA1 ($60 at Best Buy) and Zenith DTT900 ($60 at Circuit City). If you buy any of those early model boxes, you can use the $40 coupon offered by the government, reducing your out-of-pocket cost to $10 or $20. You can use the coupon for any model on the government's list of eligible DTV converters.

All three converters did what they're supposed to—they provided access to over-the-air digital TV programs when we connected them to a rooftop antenna at our Yonkers, NY, labs. Picture quality from all three was decent, but with slight differences, and there were variations in features that might sway you to one or the other.

We tested three important points:

  • The sensitivity of the tuner, indicating how low a signal level the box can receive and still provide a clear, continuous picture (when reception is marginal, the picture could break up or freeze and audio will be intermittent, or you'll see only a black screen that says low or no signal.)

  • The quality of the images they pass along to your TV

  • And features that add to convenience or ease of use.


Zenith DTT900
Zenith DTT900
Digital tuner capabilities. In addition to seeing what the converter boxes could do with off-air broadcasts, we tested to see how well each box performed when we fed it progressively weaker signals. All three boxes did an equally good job with weak signals, comparable to several late-model 42-inch flat-panel HDTVs we tested. (One important note: While the converter boxes can pull in HD and standard-def digital channels, they'll convert HD programs to standard-definition analog.) The three converter boxes we tested all have a signal-strength meter, accessible via the remote, to help you adjust the antenna to the optimal position.

Picture quality. We hooked each box up to the same TV, a picture-tube set with no digital tuner. With all three boxes, picture quality was decent from the RF output and slightly better when we switched to the composite-video output. The Zenith and Insignia (Best Buy's store brand) models—which are made by LG Electronics and appear identical cosmetically and functionally—produced a slightly better picture than the Magnavox. None had picture quality as good as you'd get with a decent HDTV, but the differences won't be that noticeable on a relatively small screen. It's not worth buying a new TV unless you're ready to change for other reasons.

Connection quirks. When we connected the RF and composite outputs to the TV simultaneously—which you might do to hook up a TV and VCR, for example—the Zenith and the Insignia showed "fixed pattern" interference noise on the composite-video feed. That didn't occur with the Magnavox. The composite-video output of the Insignia also showed an intermittent image blurring on some programs with the sample we tested.


Insignia NS-DXA1
Insignia NS-DXA1
Simplicity. We found all three boxes easy to use. Basically, you plug the cable from your antenna into the box, and then hook up the box to the TV using either the RF/antenna connection or the composite-video output. A "Setup Wizard" or "Install Guide" with each box appears the first time the box is turned on, scanning to see what channels are available in your area. You set the TV to channel 3 or 4 and then use the remote that comes with the converter box to change channels.

Format fixes. The converters enable you to adjust the size and shape of the programs coming in, which may be either wide-screen (if they're HD broadcasts) or squarish (the 4:3 ratio of standard-def programming). On an older analog set with a squarish screen, standard-def programs will fill the screen just as they do now. If you're tuned to a station broadcasting HD programming, you can choose to watch wide-screen programs in the letter-box mode (a smaller version of the full image with bars at top and bottom) or you can zoom in to fill the screen by cropping off the sides of the image. The Insignia and Zenith have a button on the remote that lets you adjust the aspect ratio. With the Magnavox, you have to use the remote and the on-screen setup menu.

Useful features. The Insignia and Zenith boxes have an electronic program guide that lists the program title and run time for the current and next programs for all channels. The Magnavox's guide shows the program title, run time, and a brief summary of programs only for the channel you are watching.

On all three boxes, you can use the remote to change the channel and adjust the volume. The Insignia and Zenith also have channel-up/down buttons on the box itself, so you can change the channel from the box. With the Magnavox, you can change the channel only using the remote. With the Insignia and Zenith, you can control the volume level of the audio outputs (via RF or stereo jacks) using the converter box's remote. With the Magnavox, you can adjust the volume only on the TV itself. None of the boxes have a menu button on the box itself, so you won't be able to change settings without the remote.

All three boxes have advanced Closed Caption user controls that allow you to change the font type, size, color, border, and opacity and the background's color and opacity. While you can connect a VCR between the box and the TV, and program the VCR to record an off-air broadcast at a specified time, you must manually set the converter box to the desired channel. That means you can't program the VCR to record two different channels in your absence, say channel 7 at 8 p.m. and then channel 11 at 9 p.m. You would have to be there to switch the box to channel 11 for the second recording.


These converter boxes are all capable of handling their basic function reasonably well, and they'll enable you to use an analog TV after the switch to all-digital broadcasts. They should give you access to just as many digital TV broadcasts as an HDTV, and all provide acceptable picture quality. Based on our tests of the first boxes to arrive in stores, the Insignia and Zenith converters provide a slightly better image and some added features that make them more convenient to use than the Magnavox. The Zenith and Insignia performed closely overall, but the Zenith didn't show the same quirks as the Insignia did when we used the composite-video output, so we would choose the Zenith. Still, if you want optimal picture quality from digital broadcasts, you'd be better off buying a decent digital TV.

There are higher-priced, full-featured converter boxes available, but they're overkill for use with an analog TV, which can't take full advantage of their capabilities. Also, such boxes don't qualify for the government coupon for DTV converters.

If you have an HD-ready TV or a computer monitor with video-friendly capabilities, the Samsung DTB-H260F would be a good choice. It produced a very-high-quality video signal that yielded a highly detailed picture and features HDMI and component-video connections. But the $40 government coupons cannot be applied to its $170 price tag since the Samsung converter isn't on the official list of eligible converter boxes.