Trovo ci sia molto buon senso in questo breve articolo del critico radiofonico del Peoria Journal Star a proposito di onde medie digitali. Steve Tarter ha la sensazione che HD Radio in AM possa costituire un passo indietro, almeno per chi ancora si sintonizza sulle onde medie con una radio analogica. Molte stazioni digitali portano inevitabilmente parecchio rumore, perché il digitale ibrido interferisce, a una certa distanza, con i segnali analogici che utilizzano frequenze adiacenti al canale occupato dalla modulazione IBOC. Tarter ha ascoltato il parere di un tecnico che lavora per alcune stazioni nell’area di Peoria, Wayne Miller secondo cui il digitale sarebbe un’idea discutibile “anche per la modulazione di frequenza”. Miller ritiene che una delle virtù più pubblicizzate del digitale, la possibilità di trasmettere fino a due canali audio aggiuntivi, è semplicemente insostenibile per molte stazioni, che già fanno fatica a finanziare con la pubblicità una singola trasmissione. Un po’ diverso il discorso per le stazioni pubbliche e religiose, insomma per tutti quelli che non si finanziano con la sola pubblicità. La sostenibilità economica della transizione al digitale, è un discorso che non sembra piacere molto ai tecnici puri che cercano di imporre l’uso delle nuove modulazioni. Ma i casi della radio satellitare negli Stati Uniti e delle delusioni suscitate recentemente dal DAB in Gran Bretagna e Germania, dimostrano che prima o poi qualcuno lo dovrà pur fare. Intanto, la HD Radio Alliance negli USA è passata alla seconda fase della sua campagna di marketing, dopo l’iniziale strategia mirata a aumentare la visibilità del sistema presso i consumatori. In un suo pezzo RadioInk annuncia che il nuovo claim del consorzio sarà d’ora in poi “it’s time to upgrade!”. Come dire, vi abbiamo detto che cos’è HD Radio, ora acquistate i ricevitori. Alla fine la decisione la prenderanno i consumatori, è naturale. Ma, conclude Steve Tarter, non dimentichiamo che a differenza dei loro colleghi proprietari di televisioni, gli editori radiofonici americani non devono passare al digitale perché glielo dice una legge federale. “E questo potrebbe spiegarci perché finora non ci sa stata una corsa alle nuove radio.” A Peoria hanno le idee più chiare che altrove.
AM radio not feeling buzz of digital
Sunday, March 30, 2008
We always expect technology to come running to our rescue. The latest cell phone or computer always packs more power or features, so the last thing you’d expect would be a technological advance that takes us a step backward.
But that’s the story when it comes to digital AM radio. Now, don’t be confused: Digital FM radio is being rolled out -albeit very slowly – without problems when it comes to reception. It’s on the old AM dial where the trouble is.
You remember AM – where top 40 once ran free with jabberjaw deejays, jangling jingles and near-constant promotion. Today’s youth are probably barely aware of the band’s existence, living in their “I” world of iPods and iTunes.
Yet AM radio now faces a problem more insidious than just being ignored. A so-called technological upgrade – the conversion to a digital delivery system – threatens to turn the dial into a sea of static.
Don’t take my word for it. Wayne R. Miller, a radio engineer for a number of Peoria stations as well as stations throughout Illinois, has no love for the digital direction that radio is headed in. “It’s a stupid idea even on FM,” he said.
For the record, Miller doesn’t think much of the idea of sidestream stations created by digital FM. He doesn’t see how stations, already hard-pressed to scrounge up enough advertising for one stream, can afford to sponsor two or three. For that reason, Miller sees the noncommercial side – public and religious stations that don’t depend on advertising – leading the way on digital FM.
On the AM side, however, the digital upgrade means interference. “Digital transmissions on AM makes a mess out there,” said Miller, referring to when one station’s digital signal steps on another, creating buzz and static for the listener
We’ll try to keep this simple, but the “in-band, on-channel,” or IBOC, digital system is more than just unpopular among Miller and others in radio circles. It’s downright detested.
Pick up a copy of Radio World, an industry newspaper, or go to any number of online sites and review the rants. “You don’t have to be an engineer to hear crappy audio. I don’t need a scope or spectrum analyzer to hear the hash,” wrote Jim Jenkins, the owner of a South Carolina AM station, in a recent Radio World submission.
The problem results because AM signals behave differently at night, said Miller. At night, an IBOC AM signal can actually spread radio static, he said. The digital signal sends off “a buzzsaw” of interference, due to the nature of that digital signal and because, at night, AM signals bounce off the ionosphere (FM signals pass on through).
Those AM signals can come back in the strangest places, said Miller, noting that WMBD-AM 1470 has been picked up in Norway.
What bothers a lot of radio people is that AM radio has enough problems without the technology anchor.
It’s also expensive. Miller estimates that a small station could make the digital transition for $25,000, but costs are more likely to average $100,000 to $150,000 when things like rebuilding your radio antenna are factored in, he said.
Unlike their TV counterparts, radio folks don’t have a federal mandate to go digital. That might explain why there hasn’t exactly been a stampede to make the upgrade.
The Web site StopIBOC.com estimates that only 5 percent of the AM stations in the nation now operate the IBOC system with fewer than 100 stations (out of more than 4,700) running digital signals at night.