Tuesday, February 21, 2006
HD RADIO-POOR (LOCAL ONLY) COVERAGE!
LOCAL ONLY IN MOST AREAS.
Typical HD Radio digital signal only covers 10 to 20 miles, where the analog signal may cover 40 to 60 miles! "Your mileage may vary" depending on local terrain and noise conditions.
"I've built a couple of HD stations in the past year. And the real world of reception and coverage is different than any claims by Ibquity you might have read. First of all, FM coverage by HD is generally good within the 70 dbu (3.16 mv/m) contour of FM, and fairly robust inside the 5 mv contour of AM stations. Outside of those general coverage contours, it falls apart pretty quickly.
HD AM in particular is vulnerable to power line noise and driving under bridges and such, as is it's analog counterpart. HD FM seems to suffer the same problems as it's analog counterpart, except there is no multi-path. Dropouts, digital glitches, switching back and forth from analog to digital, yes. But no multi-path.
I was surprised by the lack of robustness of the HD signal within the primary contours myself."
"The staff was trying to figure out what we spent $120K on. So was I. The second digital audio channels are nice, but suffer the same problems as the main channel HD. They simply don't drive as well as the analog side."
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