IBOC ALERT - KDWN-AM (720) LAS VEGAS - IBOC ALERT

[ABQTom]

Sorry to bring bad news from the city of Lost Wages, and now Lost Signals.

KDWN-AM (720) now owned by Beasley class B 50kW DAN 3 towers, covers at least 12 Western US states + Canada, Mexico.

Goodye 710 KIRO to folks on the West Coast, and goodbye to the AM 710 in Mexico.

 

[BRNout]

Sorry to bring bad news from the city of Lost Wages, and now Lost Signals.

KDWN-AM (720) now owned by Beasley class B 50kW DAN 3 towers, covers at least 12 Western US states + Canada, Mexico.

Goodye 710 KIRO to folks on the West Coast, and goodbye to the AM 710 in Mexico.

It will be interesting to watch how all of this plays out in court. I can assure you that the IBOC hash from a strong skywave signal can (and does) blot out weaker stations within their nighttime contours. At least one lawsuit has been filed already, involving a station in the Rochester market at 1040 that's being hashed by powerhouse WBZ 1030. And, WBZ (a station that i really enjoy listening to, BTW) has been accused of hashing KDKA 1020 within it's protected contour too. Not to pick on them alone, WABC 770 and WJR 760 employed mutually assured destruction with IBOC hash until Citadel (owner of both) pulled the plug on nighttime IBOC. I wish that other owners would follow.

It appears clear to me that, for IBOC to work on AM, the frequency allocations on AM would have to be more spread out and a lot of licenses not renewed for this to work. If you want more bandwidth, you need more spectrum space. Clearly, you cannot have both.

 

[KeithE4]

Sorry to bring bad news from the city of Lost Wages, and now Lost Signals.

KDWN-AM (720) now owned by Beasley class B 50kW DAN 3 towers, covers at least 12 Western US states + Canada, Mexico.

Goodye 710 KIRO to folks on the West Coast, and goodbye to the AM 710 in Mexico.

It will be interesting to watch how all of this plays out in court. I can assure you that the IBOC hash from a strong skywave signal can (and does) blot out weaker stations within their nighttime contours. At least one lawsuit has been filed already, involving a station in the Rochester market at 1040 that's being hashed by powerhouse WBZ 1030. And, WBZ (a station that i really enjoy listening to, BTW) has been accused of hashing KDKA 1020 within it's protected contour too. Not to pick on them alone, WABC 770 and WJR 760 employed mutually assured destruction with IBOC hash until Citadel (owner of both) pulled the plug on nighttime IBOC. I wish that other owners would follow.

It appears clear to me that, for IBOC to work on AM, the frequency allocations on AM would have to be more spread out and a lot of licenses not renewed for this to work. If you want more bandwidth, you need more spectrum space. Clearly, you cannot have both.

20-30 kHz wide signals in 10 kHz-spaced channels was a bad idea from the start. It's bad enough with regular AM, but with the entire 20 kHz channel being occupied with a strong signal (which doesn't always happen with AM), it makes it much worse.

It just doesn't make sense for channels to overlap in any mode. Imagine how much of a mess we'd have if the FCC had done this with TV channels. If Channel 3 occupied 57-63 MHz instead of 60-66 MHz, think of the interference to Channel 2. WCBS-TV would be invisible in parts of the New Jersey & Connecticut with severe interference from Philly and Hartford.

That's how they allocated AM channels - each channel is spaced at half the bandwidth used (I realize that this wasn't the intent back in the '20s and '30s when the highest audio frequency transmitted on AM was 5 kHz at best). Allowing 10 kHz audio on AM was a bad enough idea. Allowing that much bandwidth in digital makes it that much worse.

FM would have a similar problem, which is probably why no FM stations are on even-numbered-decimal frequencies (92.2, 98.6, etc.).

 

[ABQTom]

Class D stations on 710, 730 might be really hurt. I know the OM at 730 in Ashland/Medford, Oregon (down to about 40W at night) and have been meaning to give him a call. IBOC should not be allowed at night, anywhere.

Also I'm only 5 miles from the KDWN towers and get blasted at night. Something really strange happened when they went to IBOC. The Analog Signal strength meter on an old portable Panasonic was "stuck" at 2 units on the dial. I had to knock on the console to make it work. Makes no sense, but who knows?