Set by program: Presumably sets the aspect ratio as the content maker requests.
Letterbox: Keeps wide-screen programs in their original form, but adds black bars on both the top and bottom of the picture.
Cropped: Maintains the proper aspect ratio, but literally crops out of the extreme right and left sides of the picture.
Squeeze: Doesn't remove any part of the picture, but distorts the aspect ratio, making people look tall and skinny.
The DTT901 also doesn't have a problem displaying a full wide-screen image if connected to a wide-screen TV--which is a step-up over the RCA DTA800.
The DTT901 also has what's called analog pass-through, which means that it's capable of letting an analog signal pass through its RF output, to your TV that has an analog NTSC tuner. While it's a nice addition to the feature set over its predecessor, the DTT900, its usefulness will be limited for most users, since after February 17, 2009 the vast majority of analog TV broadcasts will stop. There are, however, some low-power analog stations that will continue to use analog broadcasts, and some people may still be able to pick up some international analog TV broadcasts if they currently receive them.
The DTT901 has a basic set of connectivity options. There are two RF-style F connectors, which are the connectors that have the screw threads on the outside and the small hole inside. One is an antenna input and should be connected to the antenna using a coaxial cable. The other F connector says, "To TV (RF)," and is a video output. This means you can send analog video and audio from the DTT901 to your TV by connecting a coaxial cable. In addition to the F connectors, the DTT901 has a composite video output, along with stereo RCA analog outputs--the standard yellow, red, and white outputs. If your TV has the proper inputs, you should use this output, as it offers superior audio and video quality over the RF connection.
Mostly everything you need to get the DTT901 running is included in the box. There are two cables--an RF cable and a composite video cable with stereo audio cables. We definitely appreciate the composite video cable, as both the RCA DTA800 and the GE 22730 stingily only include an RF cable. A single AAA battery for the remote is also included in the box.
While the DTT901 includes all the critical features you'd want on a DTV converter box, there are some extras missing. Some of the DTV boxes--such as the RCA DTA800--include an option to use with a Smart Antenna, which is a special kind of antenna that supposedly is able to reposition itself to get the best reception. We haven't been able to test this functionality on any of the boxes yet, but the Smart Antennas we've seen are so expensive we find it hard to believe it's worth the money for connecting to such a bargain DTV box. There are also a few DTV boxes--such as the Channel Master CM-7000--that feature an S-Video output, which can provide better video quality than that composite video. This should only matter if you currently have a TV that has an S-Video input.
Reception performance on the DTT901 was solid. We were able to tune into all of the major stations from our Manhattan location and we very rarely saw artifacts because of reception problems. We also tuned in from Queens, New York, and signal quality was just as good. Remember, you'll only be able to tune into the free stations broadcast over the air--that means no Comedy Central, CNN, and so on. From our Manhattan location, we were able to tune into the major networks (CBS, NBC, Fox, ABC), plus PBS, The CW, My 9, and some religious and Spanish channels. The channels you can actually receive depend on your location, and you can use tools such as AntennaWeb or TV Fool to help determine what channels you can expect to get.
In terms of video quality, we were pretty impressed with the Zenith DTT901. Switching back and forth between the GE 22730 and the Zenith DTT901 while watching The Price is Right we saw a substantial difference. The image from the GE 22730 was filled with jaggies and other image distortions, while the DTT901 looked comparatively smooth and jaggy-free. This difference was apparent on all the other channels as we flipped around, indicating it was a difference in the boxes' overall video performance and not just on a particular program.
One minor issue we did run into was some strange audio behavior, such as sibilant noises, like s's, sounding harsh and, occasionally, washed out, like an overcompressed MP3. While this was very noticeable on the DTT900, the effect is considerably lessened on the DTT901. While it's still a minor issue--and those sensitive to audio quality should steer clear--we're guessing many people won't mind or notice.