text: The Dawn Of HD Radio (washingtonpost.com) washingtonpost.com - When WHUR launched "high definition" digital radio this year, it advertised the move several times an hour on air. It slapped the "HD Radio" logo on its letterhead and employee jackets. It drove around town in a specially outfitted van inviting people to listen to the crisp, no-static sound. And it tutored consumer electronics retailers about the technology.