R.F. Burns queried:
Could you please tell us which adjacent channel stations you can comfortably listen to at your location?
All AM reception in Manhattan is problematical, frought with electrical/computer noise interference and other nasties. Generally speaking, if the AM station's transmitter is west of Manhattan in the swamps of NJ then the signals are better. If the AM station's transmitter is anywhere else then there are reception problems.
Are you saying that the IBOC sidebands are so strong that they interfere within a first adjacents local coverage area?
I am saying that there are several smaller AM stations in shadow areas surrounding large metropolitan areas (including NYC) that are being interfered with by IBOC signals on the higher power AM stations in regions where they formerly had no problems. These are regions in which these stations were formerly able to sell advertising time and are no longer able to because they can no longer be heard there. Are these regions (strictly speaking) protected by "primary coverage"? I don't know. But there are legal actions pending over several of these interference cases and you WILL start to hear about them.
This is plain wrong. Iboc has nothing to do with the interference and the ability to get a groundwave signal into Manhattan. What does effect that level of RF reaching a typical radio in NYC is first power output of the station. Let's say we have a 1 K station located 30 miles from Manhattan. A radio located in midtown has to contend with so much RF from so many sources, many of which are high power (Say 300,000 or more watts ERP from say a WINS at 1010) that receiving that relatively small amount of RF from a low powered distant station is a no go. There's a suburban station which was purchased by a Chicago are operator who thought that their 1K signal would provide a solid signal into Brooklyn. Of course anyone who knows this market would say this is crazy, but they felt because their lowe power suburban station in the midwest did an adequate job of covering Chicagos Polish speaking population, the same would hold true here. Ground conductivity alone makes this a failed argument. I've heard a recording from this station dating back to the early to mid 60's which was recorded at WNEW's east side studios and when this stations ground system was brand new (the station transmits from a swamp) and the signal was noisy and weak and about the same as it is today in that area of the city. You could never hear say WAEB 790 from Allentown in NYC due to WABC's pressence. The same holds true today.
Somehow, I've lost the nesting of the quotes above... sorry
Mr Birach purchased WNWI, a 250w signal on 1080 in Valparaiso, IN, on the basis of its good signal into Chicago.
The original Xmittr site was on the campus of the best radio engineering school ever (Valparaiso Technical Institute), and when built in 1965, nothing was spared to make the best install possible. The ground radials were "much more and many" than adequate.
When they moved to Oak Lawn, IL, and increased to 1kw, the signal in the Chicago metro became full quieting.
But if WHFB Benton Harbor 1060 goes IBOC, we WILL hear the upper IBOC sideband intermodulating with it.
Well, I won't, because I can't understand Polish, Serbian, Chechnian, etc.
There is too much steel in Manhattan for ANY AM to power its way through the whole thing.
Only the side (of Manhattan) toward the toward the station desired will have reliable coverage.
This is the scenario where no additional interference is permissable.
Cal is pointing out that despite "protected" contours, signals are often viable and listenable.
When IBOC is added in such areas, many more people lose real use of their radios than benefit from HD reception.
Who's to say that such listeners should be cut off? I know I never gave ibiquity the go-ahead to curtail my choices.
I would rather have analog AM pirates run unfettered than have HD noise splattering the AM.