MARCONI DREAMS

We’re in the midst of a digital revolution in all media, and radio is no exception. You’re hearing about “HD Radio.” But not hearing much of it yet, because U.S radio is just now switching over to digital broadcasting, and the price of a digital radio receiver is still ridiculous. But these are not the only problems. AM radio stations (540 to 1600 kHz) have just begun to convert to this new method of pumping out electrons, and they’re interfering with each other, and themselves, at night. Nighttime has always been a problem and a blessing for AM — the original radio transmission platform. When the sun goes down, a station’s signal rushes skyward — it’s called the station’s “skywave”–and bounces off the ionosphere, then off the earth again, and skips over great distances. One of the geek joys of radio has always been “DX-ing” — distance listening. “Hey Maude, c’mere! I’ve got Del Rio, Texas!” Now, the big-nighttime-signal stations — those on what we used to call “clear channels”–are having fuzz problems because of their own and others’ new digital signals. It’s the system the U.S. adopted, called IBOC, (In-Band-On-Channel), which makes it possible to transmit the new digital radio information on the same frequency with the old analog signal. What it seems to be doing is killing the possibility of skywave broadcasting — picking up San Francisco stations in Houston, and so on. A lot of people in U.S. radio are unhappy about this, though radio has long been considered a local-only medium. You can read more about this in the radio trades (see my right column for links), but here’s a telling little article by a broadcast engineer, writing in Radio World this week. This guy, in his dispassionate (sorta) way, delivers his analysis of the problem. It’ll give you a taste of radio guy talk. Just plow on through the technical terms and jargon. Will the radio guys have to fix this bug, or will the clear channel station owners just have to get over it? Stay tuned.