An extensive study by NPR Labs points to significant trade-offs between the audience reach of digital HD Radio and the amount of interference to analog FM. Even though its transmission power is just 1 percent of analog FM’s, its range for listeners in cars comes close to equaling analog, the CPB-funded study found. But HD reaches areas including little more than one-third as many indoor listeners. To extend its range, the National Association of Broadcasters in January joined other industry groups advocating an optional power boost for HD Radio, permitting stations to emit digital signals at 10 percent of analog transmitters’ power. The FCC has not yet begun a proceeding to consider the change.
NPR took a different tack March 16 in the ongoing assault on the FCC’s controversial plan to license low-power FM (LPFM) stations. Lawmakers and the National Association of Broadcasters have opposed the measure outright, but in a petition for reconsideration and a motion for stay, NPR asked the agency to take another look at some aspects of LPFM and delay implementing the proposal until July 15. Specifically, NPR requested greater protections for translators, radio reading services, full-power stations on third adjacent channels from LPFM stations, and potential digital radio technology. The network says the motion for stay would allow more time for NPR and FCC lab and field tests of interference expected to be caused by LPFM stations. On Feb.
With about 90 percent of the population covered by its signals, public radio has reached all the ”easy” regions and is now filling in the gaps, usually in less-populated areas. Even when there’s money to add repeating transmitters, however, there are often technical glitches. The furor has died down somewhat in recent weeks, but when public radio first came to Chillicothe, Mo., in August 1993, hundreds of people wanted it to go back where it came from. In an area where households without cable were accustomed to picking up Kansas City Royals games and other programming on weak signals from TV stations 70 miles away, the new 100 kw FM signal was so much closer that it blasted the ballgames right off the tube. Though the outrage was new to Chillicothe, similar cases of ”blanketing interference” often had occurred and subsided elsewhere and will arise again in other remote areas as public radio (or kind of station) fills the gaps in the national map of FM service.