Interference and fidelity have been the bane of AM radio broadcasters and listeners since the medium was developed in the early 1900s. In fact, what drove Edwin Armstrong to invent FM radio was that he hated the sound of AM, which he also helped develop.
Over the years, technical improvements have helped make AM sound better, but the erosion of listeners from the band has continued. One potential solution was digital HD radio, but the hybrid HD system introduced its own problems by increasing overall interference on the band, leading many stations to abandon it.
But what about all-digital AM? Does it have the potential to fix all that ails the band? In 2018, WWFD/Frederick, Maryland decided to find out. The station went all-digital under temporary authorization by the FCC (later approved for permanent full-time use).
That’s a huge risk. All-digital broadcasting means that only those with HD radios can hear your station. All-digital renders the vast majority of AM radios obsolete, as all they would “hear” is static (before eventually tuning out, you’d imagine). Having no listeners tends to hurt stations that rely on an active listener base to sell advertising.
Yet the idea is not unprecedented. Indeed, there were few radios available at the genesis of AM itself in 1922, and FM stations languished for years due to a lack of receivers.
Likewise, the payoffs are huge. For a station that is already losing money, it begs the question – why not take the chance? Of course, one could say that regarding programming itself, so there are multiple ways to take risks that might pay off big in the future.
In the case of WWFD, the management felt the risk was worth it. After five years of testing, the station has announced that it will remain all-digital, playing a wide-variety music format called The Gamut.
“It was my intention all the way back then that this would be permanent,” station programmer and engineer Dave Kolesar told radio engineering newspaper Radio World. “We have learned that all-digital AM broadcasting is much more robust than the hybrid mode of HD AM, and in fact has many advantages over analog broadcasting in terms of sound quality and metadata.”
Metadata is the capability of sending song information, album artwork, and even secondary audio channels over the air. “It makes AM look and sound like every other broadcast service in the dashboard, and that’s essential to the future of the band,” he said, adding “it even works well in electric vehicles.”
Another advantage of all-digital? The reception is almost instantaneous, much like analog. The hybrid mode on both AM and FM takes a second or two for digital to kick in. Likewise, interference between stations is reduced, as the signal is centered more tightly on the assigned frequency; hybrid mode puts the digital stream on the sides of the analog signal.
You can hear samples of the station online at meduci.com/airchecks.html. One of the included files demonstrates the fast reception capability, and I have to admit, I was surprised how fast it clicks in.
Obviously, digital is not for everyone, and programming trumps sound quality … it makes no difference what you sound like if no one wants to hear what you broadcast. While a station like KFI (640 AM) has too much to lose as one of the top-rated stations in town, a station like KABC (790 AM) might well consider it. There are rumblings that KMZT (1260 AM) will try testing all-digital at least temporarily at certain times of the day, and I think it would be a great idea. I’d like to know just how far the all-digital signal can travel, and if it can do so at night. It could indeed be a game-changer.
Kolesar agrees, telling Radio World that all-digital is something every AM broadcaster needs to move toward, sooner rather than later. “Analog AM listenership is declining, and we need to stop worrying about obsoleting analog-only radios … because fewer people are even bothering to turn them on.”
First published by DailyNews. Read original here
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