You Can Still Catch What You Might've Missed

Webinar explores tech issues, using spring convention to provide a snapshot
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Our webinar “25 Things You Might Have Missed at NAB,” sponsored by Nautel, was a big success. If you haven’t viewed it already, you still have a chance to catch it; just register for free.

The name actually is a bit misleading. Our subject in the webinar really is anything that’s going on in radio engineering and regulation, using the recent spring convention to provide a snapshot. So regardless of your interest in the show itself, or whether you attended, this is a useful tour through radio’s technology issues and news headlines.

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Some nuggets:

A paper by Dave Hershberger at Continental Electronics came up in the webinar; he advises engineers to be aware of possible unintended consequences before they increase HD Radio power.

Apart from adjacent-channel interference, which tends to get a lot of attention, is the topic of interference to your own analog signal, or self-interference. Hershberger says this will be aggravated by increased digital power.

The level of self-interference will depend on several factors including receiver bandwidth, extended hybrid mode and multipath propagation. The problem affects primarily SCA subcarriers and stereo reception. Self-interference is also a function of analog deviation.

He discussed other consequences to increased digital power, which we touched on in the webinar. His most controversial conclusion is that increasing peak-to-average ratio, or crest factor, reduction may have the unintended consequence of “pinching off” the analog signal in certain receivers.

He thinks increased crest factor reduction, as proposed by some manufacturers, might be good for the transmitter, allowing higher analog TPOs; but he says it is potentially very bad at the receiver by causing digitally induced analog signal “pinchoff.”

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A graphic from Dave Hershberger’s NAB presentation addressing the issue of increased analog self-induced noise with increased HD power. This was among the topics discussed in our webinar. His point is that since most broadcast revenue derives from the analog signal, it should be protected. Hershberger will be writing about it in an issue of Radio World Engineering Extra.

An interesting trend is that more U.S. manufacturers seem to be using offshore labor — and making no bones about it.

Radio Systems used a team of engineers in India on its new Platform console project, complementing its own designers. Similarly, Axia built its latest console in China.

This makes sense given the nature of the global economy and the ease with which the Internet lets us do business anywhere; and these certainly aren’t the first products taken to other countries to be designed or built. But I’ve worked in the equipment industry for many years and don’t remember a time when U.S. companies were quite as forthright about the international approach they take to product building.

A stigma that at one time may have met a U.S. company building a product offshore seems to have evaporated.

Also of note is how standards are becoming more and more a part of the “pitch” for manufacturers.

The aforementioned Radio Systems Platform features not only the company’s own StudioHub Cat-5 wiring standard, but also Ethernet, 48 Volt Power over Ethernet and the LiveWire IP network protocol from Axia. That’s on top of the CopperLan system, a kind of “MIDI for Internet” that you read about in our May 19 issue’s opinion section.

“Interoperability” and “ecosystems” are related to this concept, and we saw that at work with Nautel, which at NAB emphasized its use of, or compatibility with, technologies from Orban, Livewire, DRM and ShoutCast.

I asked David Antoine, chief engineer for big public station WBGO(FM) in Newark, N.J., what he thought was most notable at the convention. He named “Audio over IP applications that are available now, and the potential they hold for the 21st century broadcast studio.”

David notes, “On the studio side there are newer packet-based consoles that use Ethernet and IP infrastructure to interconnect and manage audio and logic paths in the studio plant. On the STL side, IP transport boxes are becoming more reliable for full-time STL. IP paths via the phone networks are becoming more widely available and more reliable. And there are several options as far as equipment to choose from.”

Voice over IP is coming into the realm of being more user-friendly, as far as phone systems and their integration in studios. A couple of manufacturers have new products coming out that will allow broadcasters to take advantage.

David said that this is really important, with phone companies threatening to pull the plug on PRI and BRI services. If so, AoIP and VoIP may be all that is left for broadcasters to work with.

Geoff Mendenhall at Harris — who was honored for best paper at the Broadcast Engineering Conference and is a past NAB Engineering Achievement Award winner — felt that among the most important themes in engineering right now is the push to offer broadband connectivity to mobile and handheld audiences.

This is notable in light of the FCC’s new National Broadband Plan. It has the potential to speed up availability of low-cost Internet connectivity, and Geoff thinks this could really change the landscape of radio and TV broadcasting.

He notes the research that’s going on in ways to improve HD Radio coverage, including hybrid crest factor reduction, asymmetrical sidebands and HD gap fillers. Also in the news for engineers is the conversion of “split-level” HD Radio transmission systems to unequally combined, common amplification — so stations can use existing equipment to elevate their HD sideband levels.

Geoff also thinks mobile DTV is important — for one thing, because it has the capability to deliver a large number of “radio-like” audio services to all the new devices out there.

That’s just a sampling. We also heard about “Modified MA1,” the updated iBiquity transmission configuration for AM IBOC intended to help provide signal-to-noise improvement in analog radios. We took a brief look at a range of interesting new products, learned about Journaline and LED lighting on broadcast towers, heard about what the NRSC has been up to and summarized headlines that had radio engineers and managers talking this spring and early summer. Some of it has been covered in Radio World; much of it has not.

The breadth of topics also points up how much important information is packed into the spring show each year. Watch the webinar online while you munch on your lunch. It’s an hour worth spending.

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