Stabbert: ‘We Evaluated It’

http://www.radioworld.com/pages/s.0121/t.8848.html

Martin Stabbert — don’t call him Marty — said his company was ready to go on at night on Sept. 14, the first date AM IBOC nighttime operation was allowed.

In calls and a memo prior to that, he told his chief engineers, “...if your plants are ready to run at night, please do. BUT - let’s monitor the results carefully. To the extent we end up with substantial IX that we can ourselves cure, we will...”

He told me, “I also said if we find issues, or are not 100% satisfied with the performance we will address that at the appropriate time.”

It took some time to get feedback. “I would imagine some people listening the first couple of nights wondered what was going on but didn’t call the station, especially since the (nighttime) launch was over a weekend.”

Some stations had no complaints, he said, and roughly the same number did.

Listeners who have complained say they hear hiss and adjacent-channel stations say they hear noise on the channel, he said, adding that most of the impacted adjacents are stations Citadel owns.

After ‘Stepping Back,’ What’s Next?

http://www.radioworld.com/pages/s.0121/t.8849.html

Citadel and Ibiquity are figuring out the next steps — and who will pay for what.

Stabbert said Citadel employees have been measuring the effects of AM nighttime IBOC subjectively — by ear — so far; it’s working with Ibiquity to determine what equipment and resources are needed to figure out a resolution.

That may involve some on/off testing and/or reducing the injection of the digital energy into one or both sidebands.

“We have a general idea of what’s going on; as we step back, we can do empirical testing with Ibiquity,” Stabbert told me.

Citadel Halts AM Nighttime IBOC Operation Amid Complaints

http://www.radioworld.com/pages/s.0121/t.8847.html

There are a lot of unknowns at this point in the Citadel AM IBOC nighttime situation, but one thing is clear: Something is going on and the company wants to work with Ibiquity to get to the bottom of it.

Citadel Director of Corporate Engineering Martin Stabbert confirms that his company is taking a step back and stopped operating AM IBOC at night on 10 stations as of Oct. 1. The stations still broadcast in digital during the day. Of its 66 AMs, 16 have converted and four more are in-process. Citadel’s conversion efforts continue.

An excerpt from his memo to staff reads: “In response to the lackluster performance, the limited benefit and various reports of significant interference, Citadel is suspending nighttime AM HD operations at this time. Please reinstate your previous procedures for daytime-only HD operation as soon as possible.”

The company has received interference complaints from listeners and stations on adjacent channels, the latter from both Citadel- and non-Citadel-owned stations in and outside the markets. (He tells me the calls from “non-Citadel-owned” stations were cordial.)

Most of the complaints center around 50 kW Class As, he said, although internally, Citadel has observed effects from lower-powered stations on adjacents at night.

Digital Signals Spark Static from AM Radio

http://online.wsj.com/public/article/SB114125971438087021-05D89puCE5WSP_r8GSeoRd_7fCE_20070301.html?mod=rss_free

Bill Harms of Elkridge, Md., likes to listen to Frank Sinatra crooning on Vegas Radio, which broadcasts at WTRI-AM 1520, a Washington-based station. But over the past year, he's had trouble tuning in to Vegas as he drives through certain neighborhoods. As he complained to WTRI owner Buddy Rizer in an email, ''there's a hiss, a hiss that did not exist in the past.''

A growing number of radio listeners are encountering similar interference -- hisses, whistles or static -- on their favorite AM stations. The problem for WTRI began about a year ago, when Bonneville International Corp.'s WTOP, the AM station at 1500, began using a digital signal that interfered with WTRI's analog signal in some broadcast areas. It's one of the unexpected consequences of the radio industry's transition to digital broadcasts.

The FCC Tunes Into HD Radio--And May Turn Off Distant AM

http://blog.washingtonpost.com/fasterforward/2007/03/the_fcc_greenlights_hd_radio_n.html

Yesterday, the Federal Communications Commission gave a big boost to HD Radio, the digital technology that permits an FM station to broadcast multiple channels and allows AM stations to sound like FM.

The FCC ruling (109 kb PDF) leads off by eliminating filing requirements for FM stations that want to offer secondary, digital-only channels. The important part, however, comes farther down, and covers the so-far neglected area of digital AM: Stations can now broadcast digitally at night, not just during the daytime.

That's good news in a purely selfish sense; I'm looking forward to hearing Rich Chvotkin call a Georgetown game without the usual static and hiss. The vastly superior sound quality of HD AM could also allow broadcasters to offer music programming as well as the usual talk/news/sports mix.

(Would-be merger partners XM and Sirius seized on this angle in a press release today, arguing that a single satellite radio firm would still have plenty of competition: "The FCC decision underlines that HD radio on the AM/FM bands provide a real alternative to satellite.")

But HD Radio AM broadcasts may also obstruct one of AM radio's oldest attractions--so-called skywave reception, in which AM signals bounce off the ionosphere after sunset and allow listeners to tune in from hundreds of miles away. For example, two years ago, a Cleveland station's broadcast of an Indians game kept me entertained on the New Jersey Turnpike; a couple of nights later, I tuned into WTWP-AM's coverage of a Nationals game in north Jersey.

Left in the dark

http://www.poconorecord.com/apps/pbcs.dll/article?AID=/20071001/LOCALENT/710010324/-1/NEWS16

Watch for the radio tower behind the Bada Bing Club on re-runs of the Sopranos. The tower's 50,000-watt transmitter on Route 17 in Lodi, N.J., sends the signal for legendary radio powerhouse 770 WABC.

This popular station has launched the biggest names in talk radio, including Rush Limbaugh and Sean Hannity.

Local ratings show that plenty of Pocono listeners tune in to AM 770.

But about two weeks ago, WABC radio became impossible to hear in the Poconos after sundown. And although the daytime signal is still strong, WABC it is not likely to he heard here in the dark again.

What happened?

An advancement in broadcast technology.

ABC Citadel suspends AM IBOC

http://www.orbitcast.com/archives/abc-citadel-suspends-am-iboc.html

An e-mail from ABC-Citadel corporate engineering has reportedly issued an order effective this morning to suspend AM In-band on-channel (IBOC) operations, according to Radio-Info.

The communication came from Citadel's Martin Stabbard, according to sources.

The order, effective immediately, is reportedly for all Citadel AMs running IBOC at night. While no reason was given for the order, it is believed that interference issues are the most likely factor.

IBOC is the method in which iBiquity utilizes to broadcast the HD Radio signal - using sidebands to transmit the digital data over AM/FM waves. But since wider channels are required, both the AM/FM implementations of the iBiquity system often cause interference with adjacent stations on the dial. As a result, lower power stations can become unlistenable if they have an HD Radio station on an adjacent channel.

UPDATE: Apparently Citadel/ABC's AM stations will suspend nighttime HD Radio transmission until they can do further work with iBiquity to reduce adjacent-channel interference. Radio-Info adds that, "the FCC allowed nighttime AM digital as of September 14 - and the complaints have mounted up."