• Converter boxes allow those with older televisions to view digital programming.old television image by inacio pires from Fotolia.com
  
  As of June 2009, all of America's full-power television stations broadcast only in digital format. While digital television -- or DTV -- offers high-definition images and improved audio quality, the new format means that those with analog televisions must use digital converter boxes to access over-the-air television channels. Numerous companies manufacture DTV converter boxes, all of which serve the same basic purpose. The boxes differ, however, in the features they offer.
  
  

RCA

• RCA's base model DTV converter is its DTA800B box. In addition to basic digital signal conversion via its Smart Antenna hardware, this box offers an electronic program guide that displays info such as program titles, run time and show descriptions. Included closed captioning options feature adjustable font sizes, colors and transparencies. The box displays digital signals in letterbox and zoomed aspect ratios. The DTA800B1 replaces RCA's former DTA800B model, adding an analog pass-through to the unit. This pass-through allows analog -- or non-digital -- broadcast signals to pass through the converter box and be tuned by analog televisions. Both boxes come with an analog TV compatible remote.
  
  

Zenith

• Zenith offers the DTT900 model DTV converter, which features program guides and closed captioning options. Additionally, Zenith's box features a "Set by Program" option that automatically adjusts aspect ratio to the programming. The box directly tunes new digital channels and displays signal strength onscreen to help users optimize their antenna positions. The Zenith DTT900 includes a remote that can turn analog TVs on and off. It also comes with composite video and stereo audio cables, as well as an RF cable. Zenith's DTT901 adds an analog pass-through feature, but is otherwise identical to the DTT900.
  
  

General Electric

• The General Electric Company, or GE, produces a line of digital television converter boxes including GE 22729, 22730, 23333 and 23334 models. While the GE 22729 features adjustable closed captioning, a program guide and a Smart Antenna connection, the 22730 box adds direct tuning and an advanced program guide that displays several hours worth of programming. General Electric's 23333 and 23334 boxes feature analog pass-throughs and are ENERGY STAR compliant.
  
  

Magnavox

• Magnavox's DTV converter box line-up includes the company's TB100MW9 and TB100MG9 varieties. The Magnavox TB100MW9 DTV box features an advanced electronic program guide, direct digital tuning features, a signal meter, adjustable aspect ratios and customizable closed captioning options. In addition to these features, the Magnavox TB100MG9 model digital converter box adds analog pass-through capabilities. The boxes themselves feature no buttons, so they rely entirely on their included remote controls.