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WYGY’s HD Radio Conversion Detailed

Susquehanna Station Provides Lessons for Group's Digital Rollout Plans

CINCINNATI What if converting to digital broadcasting was as simple as flipping a switch?

This was the dream scenario envisioned by Susquehanna Radio Corp. managers when they considered whether to begin broadcasting an HD Radio signal on WYGY(FM), a recently-acquired station in the Cincinnati market.

Country-formatted WYGY, a 50-kilowatt Class B FM station, has the distinct advantage of being within earshot of the Mason, Ohio, headquarters of Harris Corp.’s Broadcast Communications Division.

When Harris engineers needed a test bed for their implementation of Ibiquity Digital Corp.’s HD Radio system, WYGY fit the bill. With a grant of special temporary authority from the FCC in hand, WYGY began broadcasting IBOC on Oct. 16, 2002, albeit with no audio in the digital signal.

“It worked out well for us,” said Gary Liebisch, radio transmission applications engineer with Harris. “We had previously worked with (collocated) WLW to test one of our AM transmitters, so we were familiar with the site.” Even better, Liebisch said, “you can actually see the tower from our building.”

The RF technical plant of WYGY uses a high-level combined design, with the digital signal from a Harris Z16HDs transmitter and the analog signal from a Harris HT-25 CD transmitter feeding an ERI 10 dB combiner on the way to the ERI antenna. Feeding the combiner, the total analog power is 23 kilowatts, with 2,100 watts from the digital transmitter.

Project extension

“It was easy,” said Norm Philips, Susquehanna’s director of tchnical operations, reflecting on the project. “All the hard work had already been done.”

Because the HD Radio RF transmission system was already in place, it was only a matter of supplying an appropriate audio feed to the transmitter.

“We had just finished building our new studios three weeks earlier,” Philips recalled. “This was a logical extension of that project.”

Susquehanna engineers installed an Intraplex T-1 system to provide a 44.1-kilohertz digital signal from the new studios to the transmitter site and an Omnia-6 DAB audio processor to complete the transmission chain.

The significance of the installation of this symbolic “missing link” was not lost on Telos/Omnia, headquartered in Cleveland, and Omnia founder and Telos Systems President Frank Foti was on hand to make final adjustments.

The installation reportedly went smoothly, and the station was up and running with HD Radio in about 20 minutes. The only outstanding technical issue related to the digital operation, according to Philips, is the “surprising amount of heat” generated by the reject load in the tight quarters of the transmitter room. He plans to relocate the load to an adjacent room to alleviate the problem.

One concern for early adopters of HD Radio that hasn’t been a problem for WYGY so far is interference.

One consulting engineer contacted Radio World privately to say he heard interference from WYGY to WORX(FM), Madison, Ind. on 96.7 MHz. But Philips says that the station has received no direct complaints of interference from listeners or other stations.

Aside from press releases and limited coverage in local media and industry publications of the Oct. 16, 2002, HD Radio launch, there has been no promotion of the digital broadcasts on WYGY. It doesn’t make much sense to promote the technology to the listening public until HD receivers become available, Philips reasons, especially since “we don’t even have a receiver yet.”

‘Black magic’ time

For a short time, at least, Susquehanna engineers and management had an opportunity to listen to the digital broadcasts on a prototype Ibiquity receiver. Philips was pleased with the improved audio quality of the HD Radio signal, especially in the high end.

As with most A-B testing, he said, the differences between WYGY’s analog signal and the digital were most pronounced when switching from the higher-quality (HD) audio to the lower-quality (FM) audio: “It sounded like something was missing when we switched back to analog.”

Now Philips is waiting, “just like everyone else,” for retail receivers to arrive on the market so he can listen to WYGY’s digital signal again.

After putting his first HD Radio station on the air, Philips is clear about what makes a complex system such as this go together smoothly. “Have a factory engineer there to bless it,” he recommends, since “there’s still a little bit of black magic” involved in getting everything to work together.

Philips found that verifying the RF mask is more difficult than with analog, and because there’s no modulation monitor to verify that the system is working properly, he believes the expense of having a factory proof conducted is money well spent.

Harris and Susquehanna were still working out equipment costs, both overall and for the proof, in early April. The original agreement for the equipment was between Salem and Harris; Salem owned the station when the gear was installed for IBOC test purposes. Now Susquehanna is using the gear 24/7 to run HD Radio.

Susquehanna took advantage of Ibiquity’s 2002 license fee waiver program for early adopters of HD Radio, so that fee was waived.

As more stations plan to come on the air with HD Radio, Philips would like to see manufacturers offer these services on a market-by-market basis, allowing several stations to share the expense of travel and engineering time by coordinating transmitter site visits.

As for the future of digital radio as a business, Philips is cautiously optimistic. Eventually, he forecasts, “it’s a distinct possibility” that WYGY and other stations will broadcast an all-digital signal, once enough clock radios, personal stereos and other low-cost receivers are available in digital versions.

“But by then,” he adds with a chuckle, “I’ll be retired.”

How the data broadcasting capabilities of the HD Radio system will be put to use is less clear. Philips is looking to Ibiquity, its data application development partners and data service providers to lead the way.

“There are so many schemes to make money with this,” he said, but these plans seem to run counter to the recent downturn in existing data services businesses. “SCA revenue is drying up for everybody,” he said, “and I haven’t seen a business plan (for HD Radio data services) that makes sense.”

More complexities ahead

The experience of WYGY’s digital conversion is a tough benchmark to meet for Susquehanna’s other stations. The group has inked deals with Harris to provide HD Radio equipment for its two San Francisco FM Stations, KFOG and KSAN, and Philips is knee-deep in planning the build-out.

“We’ve got to do a lot more work in San Francisco than we did at WYGY,” he said, citing concerns about air conditioning, physical space and transmitter line samples, as he starts thinking again about his current projects.

Looking farther down the line, Philips muses about Susquehanna’s Class C stations in Dallas and Atlanta, where the digital conversion plans have yet to take shape.

“Separate antennas look like the way to go,” for stations such as these where the power lost in a high-level combiner can be a significant operating expense, he said, with a hopeful note in his voice. He’s awaiting the results of experiments by Bonneville and other station owners using the space combining approach before making that decision.

Clearly, Philips has his work cut out for him. But he can always look back with fondness at how easy things were in Cincinnati.