Airwaves: October 30, 2009
HD Power Increase on Horizon?
One of the major problems with HD Radio, the trademark for the digital in band broadcasting system authorized in the United States, is reception. For some people in some areas, it is just hard to receive. Even in strong signal areas, it can be trouble, requiring longer antennas and more fiddling ... very much like the early days of color television broadcasts.
And portable HD radios? Forget it.
This is because HDs power is limited to one percent of a stations analog signal. A five thousand watt analog powerhouse becomes a 50 watt light bulb. It is a testament to the system that it works as well as it does, given the power limitations.
There has been some research, much of it from National Public Radio, looking into the effects of increasing digital power on stations using the HD system. And there has been a proposal to increase power tenfold, so that a stations digital signal is as much as ten percent of its analog signal. According to research and tests, this would do much to solve the reception problems and even allow portable radios to reliably receive HD signals.
At what cost? Good question. The increase in digital power causes an increase in interference. Its obvious in the AM band -- which to my knowledge is not part of the suggested power increase -- with a white noise sound that drowns out adjacent stations if they are there. Old time computer users will recognize the sound as the same sound a modem makes when connected to a telephone line.
On FM up to now, the HD hash has not been a huge issue because the interference to analog reception is far less noticeable on FM than AM. Some radios may be fooled into thinking a station is no longer there, but that is rare. It appears that an increase in power, however, will cause some problems for analog listeners, especially those traveling in cars ... the majority of radio listening in many cities.
NPR wants to see what would happen if a station increased HD power to something less than ten percent, as an interim move to the full ten percent. Along the way, they want to see what can be mitigated. A proposal to do just that is being floated by NPR, and the FCC is investigating the idea as well.
My opinion? While HD detractors will claim I am a shill for HD Radios creator Ibiquity Corporation, I believe it is worth a try. We wont really know the effects of a wholesale power increase until it is tried. The doomsdayers were wrong before when they said HD would destroy radio, and I would like to see for myself.
Saul Levine, owner of KKGO (105.1 FM) and KGIL (1260 AM) has filed a complaint with the FCC regarding CBS Radios simulcasting of the Inland Empires KFRG (95.1 FM) signal on KTWVs digital signal (94.7 FM HD-3).
Levines contention? That CBS is using an HD signal to illegally extend K-FROG outside of its primary coverage area.
Levine has a valid point here. It will be interesting to see what the FCC thinks as the complaint makes its way through the system.
Copyright © 2009 Richard Wagoner and Los Angeles Newspaper Group.
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