I made a series of short recordings at my cottage at Klinger Lake near White Pigeon, Mich., on the evening of Sept. 19, 2007.
We are roughly 130 miles from these transmitters (WSM, WBBM, WGN, WSCR, WHAS, WJR and WLW). Normally in this area, we can receive all of the Chicago 50 kW stations with a good listenable signal, day or night.
The recordings were made using a Zoom H4 recorder and a GE Superadio III. I made the recordings acoustically because I did this on the spur of the moment, and that also allowed me to say a few words to identify the stations. I have a series of about 12 recordings of a number of stations, including two additional files of WGN and WBBM.
What I found was that in the evening, the IBOC noise sidebands from adjacent-channel stations over on the East Coast were so strong that at times, they completely wiped out the 50 kW Chicago stations that can normally be heard very well in my area. In other cases, the noise was just really annoying.
I listened on other evenings the past week, and the results were the same. What you hear on the recordings is typical of reception in this area. In some cases, it’s even worse — the adjacent-channel interference completely obliterates the desired station only about 130 miles from the city.
IBOC is a failed technology that has no place on the AM dial. It is a huge disaster. If this is the future of AM radio, I will not be listening. There are too many other, better alternatives now!
By the way, WGN sounds bad even in Chicago during the daytime. There is always a hiss in the background. I haven’t measured it, but I’ll bet it’s not even 30 dB down.