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Radio Show: Walden Expresses Groundwave Concerns

NAB Labs tests all-digital AM on more stations

One of the items mentioned by Acting FCC Chairwoman Mignon Clyburn in the NPRM for revitalizing AM radio concerns skywave protection.

Just before the opening session engineers and attorneys here at the Radio Show in Orlando, Fla. have been debating technical solutions to help AM combat the rising noise floor and other ills limiting AM’s coverage area these days.

CBS Radio’s Glenn Walden said his company’s official position is that it’s not necessary to protect the skywave anymore. Relaxing those protection rules “would allow a lot of stations to come on, but we are concerned about our groundwave,” he said. Doubling an AM’s power would get 3 dB more in coverage, he noted, “but the noise floor is so high you really need something like 10 times the power.” However, a power increase would also increase a station’s electricity bill and their digital conversion costs.

Testing of iBiquity Digital’s all-digital AM technology continues. Beasley’s head of engineering Mike Cooney is now head of NAB’s Technical Committee.

He said in addition to the testing discussed at the spring show of WBCN(AM), Charlotte, N.C., NAB Labs has now conducted all-digital testing on WBT(AM), also in Charlotte and WNCT(AM) in Greenville, N.C.

The data is being evaluated. NAB Labs is looking for other stations to test on, especially Class C AM facilities.

The engineers and attorneys debating the so-called “digital sunrise” also discussed the merits of a receiver mandate to go with that; namely getting Congress to persuade manufacturers to keep including AM in their receivers, including portables. HD Radio portables, for example, are FM-only.

NAB is not discussing a digital sunset; a source told Radio World that technology transitions take time since not all stations can “go at once.” Such transitions are best as an “evolution” and not as a mandate, said this source.