Should HD Tuners Be Mandated? (Sep 10, 2008)

For one thing, it would jack up the price of the receivers. The cost could be at least $50 per receiver depending on the manufacturer.

For another thing, the range of the digital signals are small because of a government mandate that the digital signals have to be low or else there would be a lot of adjacent channel interference on the already crowded FM dial, especially in the area between San Diego and Los Angeles.

Have you tried listening to XLNC1 and KPFK while driving around North County? It's a signal dogfight between the two stations sharing the same frequency at 90.7 FM. I thought that XLNC1 had vacated the spot by this past February, but they didn't. That's what would happen if digital signals broadcasted at full power. It would be a mess.

A new NPR study says that more power for HD digital could mean more interference for "regular" FM. Current HD signal power is limited to about one percent of the analog transmitter power. Read the full article at Current.org.

For example, KMYI 94.1 broadcasting at 100,000 watts has to broadcast its digital signal no more than 1,000 watts. For many other San Diego metro stations, the digital signal powers can range from 500 watts for a 50k analog stick down to 150 watts for a 15k analog stick. With power that low, it's impossible for fringe listeners to receive a decent digital signal. Reception is available if you're literally within the sight of their transmitters.

The NAB and other broadcasters are asking the FCC to let them broadcast up to ten percent of their analog power output. Steve Behrens of Current.org disgrees and reasons that "an extensive study by NPR Labs point to significant tradeoffs" – that "digital’s interference with analog would nearly double, affecting 26% of listeners in vehicles...and that “41% of public radio stations would lose one-third or more of the car radios their analog signals can reach" at the moment.

It would be a mistake to mandate HD tuners into radios because of the very limited range of the digital signals.

The way it is now, people are not going to buy HD tuners anytime soon. There isn't much difference between an analog and a digital signal if the programming is as stale as ever. Nobody is going to bother with an HD tuner if iPods are playing what the listener wants.

What could work for HD radio is to get a slice of the VHF channel 2-6 freqency spectrum so that the FM stations could broadcast digital signals there and at full power. The difference would be that each station could use only ONE frequency (just to make it fair so that nobody gets eight frequencies for one market) for digital broadcasting, but they could broadcast up to eight multicasted channels from one stick. The downside would be that there wouldn't be any so-called "lab" concepts like Pride or New Rock formats. Each multicasted channel could also be programmed by an outside company like a smaller radio business who leases a multicasted channel from the licensee for a monthly fee. Maybe Clear Channel could lease KIOZ-HD3 to Free Radio San Diego for a fee.