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.