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Symposium Probes Tech Problems and Cures

RF noise, SFNs, IBOC time alignment and new FM directions discussed at IEEE BTS

HARTFORD, Conn. — Broadcast plant issues, the growing impact of manmade RF noise on broadcast operations, audio measurements, digital-only AM radio and resolution of problems peculiar to HD Radio were in the forefront of this year’s IEEE Broadcast Technology Society Fall Symposium.

It’s an annual gathering of radio and TV engineering personnel that began in the early 1950s in the nation’s capital. Attendance at the October event topped 200 — a record for recent years — and included students and their professors from Connecticut’s University of Hartford and Quinnipiac University.

Symposium organizers David Layer, Jim Stenberg and Roz Clark, from left, smile after learning of the record conference attendance.BROADCASTERS’ WORST ENEMY
Conference proceedings began with a Wednesday morning welcoming address from BTS President Bill Hayes, then moved to a succession of presentations starting with John Kean of Cavell Mertz & Associates and a look at the latest audio level measurement methodologies, along with a description of measuring devices and techniques employed in broadcasting over 75 years. Kean noted that during this time, more accurate metering devices and measuring technologies have continually helped to create improved listening experiences for broadcast audiences.

Proceedings then shifted to an area in which matters have gotten progressively worse as broadcasting has evolved: radio frequency noise. A special tutorial session called “Manmade RF Noise Issues” was chaired by Glynn Walden, now a consultant to CBS Radio. It featured four presentations on this growing threat to broadcasting and what is being done to address it.

Steve Johnston, director of engineering and operations at Wisconsin Public Radio, described a series of indoor and outdoor FM band noise measurements he had conducted, and how the rising noise floor was affecting listeners.

He noted that many complaints about poor FM public radio reception were directly traceable to new consumer devices purchased by the complainants. His outdoor measurements identified a relatively new and very potent noise generator: traffic lights that have converted from incandescent bulbs to LEDS. Johnston said he had complained to the FCC about this and a field inspector was dispatched to investigate.

Participants travelled from as far as South America, Asia and Europe to attend the three-day event. “He agreed that the levels were excessive, but took no action against the municipality which owned the traffic lights,” said Johnston. “In my view, regulatory agencies have completely lost control of the situation. I haven’t seen very many penalties for those exceeding interference levels.”

Johnston was followed by Tom King, president of Kintronic Labs, who provided an update of anti-noise actions undertaken by a number of organizations, including the Association of Federal Communications Consulting Engineers, the Society of Broadcast Engineers and the National Public Safety Telecommunications Council. He noted that the FCC had established a website for filing complaints about RF interference.

“Current FCC Part 15 and Part 18 rules need to be expanded to address the noise floor spectrum,” said King. “The FCC needs to take action to remediate this situation.”

Amateur radio operators or “hams” were part of the radio communications scene long before broadcasting got started. The largest amateur radio organization in the world, the American Radio Relay League, is headquartered in nearby Newington, Conn., a fact that was not overlooked by symposium organizers. They made sure the program included speakers from that organization.

First up was the ARRL’s CEO Tom Gallaher, who in a luncheon keynote described the mission of the organization and noted the frequent involvement of the amateur radio community in tracking down and helping to resolve RF interference problems.

Gallaher cited a recent example in Evanston, Ill., where keyless entry/ignition vehicles parked in a certain area of the city had become immobilized and cell phones ceased to operate. He said the Evanston police department initially contacted the FCC for assistance but were referred to the manufacturers of the automobiles. In desperation, the police turned to the amateur radio community for help.

Paul Shulins, director of technical operations at Greater Media Boston, describes testing to evaluate the effect of bitrate reduction on rating service watermarks transmitted with program audio. “They called us and several of our people … discovered that the source of the interference … was a very noisy neon light power supply,” said Gallaher. “The FCC finally did send a field engineer out to inspect, but his car wouldn’t start either.”

He was followed by Ed Hare, chief of the ARRL’s test and measurement lab chief, who continued the noise theme with a detailed description of the ongoing work the organization is doing to help track down “unintentional radiators,” including noisy electrical power lines.

“The utilities have blown us off, have blown the FCC off, have blown the NAB off — and this needs to change,” said Hare.

Noise of a slightly different nature was addressed by the NAB’s David Layer in his presentation “All-Digital AM Co-Channel Interference Test Project.” Those results have been reported in past issues of Radio World.

The symposium featured a special session addressing HD Radio “diversity delay” issues. Presentations included “Synchronizing IBOC Broadcast Components for Constant Diversity” by Nautel’s Philipp Schmid; “HD Radio Diversity Delay Field Observations” by iHeartMedia’s Alan Jurison; “Broadcast System Architecture for Maintaining HD Radio Diversity Delay Alignment” by GatesAir’s Tim Anderson; and “HD Radio Time Alignment” by Ben Barber, president and CEO of Inovonics.

Contemporary radio technologies remained in the spotlight with a report on continuing work in implementation of FM single-frequency networks, improvement of FM combiner/filters, and transmission of digital audio from studio to transmitter.

Lynn Claudy of NAB, right, accepts the IEEE Jules Cohen Award for Outstanding Broadcast Engineering from BTS President Bill Hayes. The award is named for the late “dean” of Washington, D.C., broadcast engineers. Also discussed were new methodologies for processing and displaying data from remote monitoring sources, use of FM RDS by power companies in “smart grid” applications and a study of the impact of bit-rate reduction on the “hidden tones” (watermarks) transmitted by stations as part of the Portable People Meter audience rating methodology.

In all, the symposium included some 35 technical presentations.

The event featured a Friday awards ceremony. Joseph Davis, president of Chesapeake RF Consultants, and Tim Laud, senior technical staff member at Zenith Electronics, were presented the Matti S. Siukola Memorial Award, recognizing the best papers delivered at the previous year’s symposium.

Lynn Claudy, NAB senior vice president of technology, was honored at the ceremony as the 2016 recipient of the Jules Cohen Award for Outstanding Broadcast Engineering.

Next year, the BTS Symposium returns to its Washington origin. The Arlington, Va., Holiday Inn will host the event on Oct. 4­–6.

James O’Neal is an IEEE Life Member, a member of the Broadcast Technology Society’s Administrative Committee, the BTS historian and editor of BTS quarterly publication Broadcast Technology.