106.5 The Arch: Analog vs. IBOC

Frequency Without IBOC-DAB With IBOC-DAB

106.1 MHz WSMI-FM Litchfield, IL (clear) WSMI-FM Litchfield, IL (some interference to Stereo pilot)

106.2 MHz clear Wiped out by digital sidebands from WARH

106.3 MHz WQRL Benton, IL (occasional signal) Wiped out by digital sidebands from WARH

106.4 MHz Analog sidebands from WARH Digital and analog sidebands from WARH

106.5 MHz Center frequency Center frequency

106.6 MHz Analog sidebands from WARH Digital and analog sidebands from WARH

106.7 MHz WZNX Sullivan, IL (occasional signal) Wiped out by digital sidebands from WARH

106.8 MHz clear Wiped out by digital sidebands from WARH

The digital sidebands from WARH (licensed to Granite City, IL) give the Stereo pilot from WSMI-FM some interference, along with the digital sidebands from KPNT. In addition, competitor KIHT (96.3 MHz) has far better Stereo separation (up to 70 dB) than WARH (no more than 10 dB separation). This is another example of why “HD Radio” should never be implemented. The interference to WSMI-FM’s stereo pilot is with the antenna pointed toward the transmitter site of WARH in southern St. Louis County, MO.