(note: I cross-posted the text below to the AMDX list of the Worldwide TV FM DX Association list--fhp)
What does a 50KW AM station 65 miles from the transmitter in-pattern sound like during nighttime hours when IBOC transmitters on adjacent channels transmit IBOC ('HD Radio')? A hissing mess. This was observed during a random check at 6:51pm CST (UT March 2 @ 0051) during a KAAY airing of the Focus On The Family daily radio show.
This occurs when KRLD 1080 is at a strong signal level. KAAY 1090 suffers not only from WTAM's IBOC interference on 1100 but also from KRLD on 1080.
Another sad chapter in the decline of what was once Arkansas' premiere radio station.
Fritze H Prentice Jr.
Star City, AR
Thank you, Fritze...IBOC is "In Band On Channel" which, if I'm not mistaken in my description, also allows data transmission systems on top of the carrier & audio of the station's transmission. Yes, it degrades the quality of the signal...but the owners of the station (and I won't name any names) don't care...it's all about the MONEY....
And as Fritze also added, "...if they cared any about (IBOC interference), KAAY would file an FCC interference complaint about KRLD and WTAM's IBOC and perhaps the FCC would consider banning nightime IBOC transmissions."
Fat chance, especially since the FCC is looking for money, too...and when the government passes rules, regulations and legislation, the money goes into a General Fund...and the FCC sees very little of it, so why bother? The frequency spectrum is finite and the government is always looking to sell off slices for more money. One recent intrusion is into the 420-450 MHz Ham band, where they've allowed other users of a business sort. Even though we Hams are already secondary users, this third user must accept interference from us, but guess who'll most likely get favor? That's right, the third user who's piddling their money into the General Fund....
So much for quality programming and communications...expect over-the-air and other communications and broadcasts to degrade further. My best solution is using radio equipment and audio gear that can at least null and tune out at least some of the interference...but that still doesn't solve the problem.
Again, thanks to Fritze for bringing this to our attention. Maybe as Hams, we should file a complaint, as well.
Bud S., KC4HGH (firstname.lastname@example.org)