1190 KEX First Portland HD AM IBOC Station
Now we get increased daytime noise and hiss in addition to already narrow bandwidth and analog distortion caused by the harsh brick wall filters required for both analog AM and HD IBOC to co-exist on the same station. Every AM radio, I own reproduced the 1190 KEX IBOC noise, despite industry claims otherwise. My better radios really sound terrible now, just as I said they would.
Update: I've got AM HD Radio samples for 1190 KEX up now on the samples page. Ideally, I'll add analog AM samples to the mix in the next few days.
HD FM, at this point, is largely benign in that most existing radios do not see a change in service quality level. As I suspected, the story would be considerably different for AM. 1190 KEX now sounds like a weak, out of town station during the day because of the increased noise the new HD Radio signal brings with it.
Look for AM 620 KPOJ to be next in line for the noise treatment as the HD AM digital downgrade continues here on Portland Oregon Clear Channel stations.