820 WNYC(AM) plans to conduct an all-digital MA3 test of AM HD Radio next month.
The test is pending FCC approval, but its owner, New York Public Radio, expects to receive the go-ahead.
NAB is supporting NYPR’s effort, and its Vice President of Advanced Engineering David Layer says all-digital AM is becoming a more viable piece of technology for broadcasters. He cited the increased presence of HD Radio in the marketplace. Fifty-eight percent of new cars in North America ship with the technology, according to Xperi.
On the day of the test, Dec. 8, Steve Shultis, Jim Stagnitto and Dannie Raghunath from NYPR’s engineering team plan to drive around New York City’s perimeter in what Shultis described as a “corkscrew” route. They will assess the digital signal’s performance in the outer boroughs of the city and then turn inward to areas like downtown Brooklyn, Manhattan’s Wall Street and Lower Broadway. The trip will conclude by going directly north through midtown. Representatives from Xperi will also be present, and the HD Radio developer will provide a vehicle and equipment to measure and record observations during the test.
“We need to see how this sounds in the urban canyons,” Shultis, NYPR’s chief technology officer, explained, characterizing the chance as groundbreaking to test HD-only AM in a major urban setting like New York City and the surrounding Tri-State region. He complimented the diligence of his two lead engineers, Stagnitto, NYPR’s director of engineering, and Raghunath, its assistant director of engineering, RF system, on the project.
820 WNYC runs 10 kW directional daytime and 1 kW directional at night. Under the test, WNYC will turn off its analog transmitter and run the IBOC digital standard exclusively. The main transmitter to be used is a Nautel XR12 using an AM IBOC digital Nautel exciter, provided by Xperi. Shultis says the power level will be set according to the IBOC AM mask measurement method with support from Nautel representatives to determine the precise level.
NYPR and NAB see this as a doubly beneficial opportunity, as Hubbard’s all-digital 820 WSHE(AM) in Frederick, Md., operates on the same frequency. Shultis is especially curious about WNYC(AM)’s HD performance in its back-lobe directional null southwest of the transmitter site. In areas like New Jersey, he has received reports of WSHE’s HD signal decoding over WNYC’s analog signal. “I’d expect our HD signal to decode instead during the test, but it’s those kinds of scenarios we’ll be watching for,” he said.
Layer said NAB will conduct drive tests through WSHE’s northern coverage area to check for any interference. “It’s the first opportunity to characterize co-channel performance between stations,” he said.
WSHE is one of a small handful of AM stations operating with the MA3 all-digital mode; in fact Radio World knows of only two doing so full-time at present, the other being 1260 WYDE(AM) in Birmingham, Ala., owned by Crawford Broadcasting. 1470 WYGG(AM) in Egypt Lake, Fla., experimented with the mode, as have 650 WSRO(AM) in Ashland, Mass., and 1230 WFAS(AM) in White Plains, N.Y., but each is now silent.
Shultis has also reached out to SBE’s NYC Chapter 15, inviting members to submit reports on test day. “It works out well that it’s a Sunday, as traffic should be light and we can all cover a lot of ground,” he noted. He welcomes feedback from listeners and hobbyists and indicated WNYC will run on-air promos about the test as the date approaches.
With the medium being examined in the public sphere, as bipartisan support continues to roll in for the proposed AM Radio in Every Vehicle Act, Shultis says he sees this exercise as very instructive.
“I think the question that’s on everyone’s mind is if AM can stand a chance against the volatile world of electromagnetic interference,” he said.
WNYC, under Shultis, was an early adopter of the IBOC standard for both its main 93.9 FM signal and the initial hybrid AM form. It began testing HD Radio on FM as early as 2003. 820 AM primarily simulcasts 93.9 FM’s programming.
MA3 was authorized by the FCC in 2020, which NAB says it was instrumental in securing.
(Read NYPR’s FCC authorization request to test the MA3 format.)
