If you have an analog TV and analog Comcast cable service without a converter box, and you turn on WGBH-TV-2 right now, you're going to see something very wrong: video of normal WGBH programming, accompanied by audio of WGBH's continuously-looping Ready for Digital TV special.

The picture says "This TV is DTV Ready" while the sound says, from time to time, "This TV set is not ready for the switch to digital TV in February 2009". Also, the picture is shrunk down and enclosed in a black box.

WGBH says this is a "Comcast engineering problem", not a problem with WGBH's broadcast or with your TV set.