Living 13 miles line-of-sight of WTIC’s 50,000-watt transmitter site on 1080 kHz makes DXing on 1070 and 1090 kHz very difficult especially since WTIC uses IBOC (In-band on-channel), a hybrid method of transmitting digital radio and analog radio broadcast signals simultaneously on the same frequency. 
WTIC's IBOC'd signal extended from 1065 to 1095 kHz!
With IBOC on, I can’t hear a thing but IBOC on 1070 and only 50,000-watt WBAL manages to break through on 1090.
Good news is that it seems that WTIC is no longer using IBOC. It has been off for weeks (maybe months) and I hope it is not coming back.
Hurrah!
Sadly, HDradio, preferably in MA3 mode (full digital) is one of the few ways forward for AM stations. I can only assume that "in-band, on-channel" was intended to be applied to the all-digital mode, which barely leaks out of the 10-kHz slot as opposed to MA1 (in the image) that seriously impinges on both adjacent channels.
ReplyDeleteAs the number of stations continues its decline, that interference will get less and less.
It does look like AM stations in our local area have stopped their IBOC platform on the AM band. A sweep of the band reveals zero stations appear to be using it, most notably, WTIC, WCBS, WINS, and WBZ look nice and clean. What a debacle that initiative was! I do like IBOC on the FM band where many stations transmit their AM fee on a sub-channel. I hope that practice continues. 73, de W1AEX
ReplyDeleteLine of sight, WTIC was the worst, but I imagine it was even worse at your QTH, Rob! Anyways, good riddance to IBOC.
DeleteI swept the AM band this morning (12-19-2023) from top to bottom and see no IBOC in the Hartford, Boston, or NYC area. That is a welcome development in my opinion. WTIC, WCBS, WINS, and WBZ were the most prominent IBOC stations in my area. Reception of WTIC AM, which is 12 miles away from me, was very annoying as the signal would continuously switch back and forth from AM to HD and my receiver had no means for disabling HD reception. Glad to see it going as I can easily receive WBAL now! 73, de W1AEX
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