Installing FM HD Radio and Making it Work
6.1 Getting started with the FM HD Radio installation
The FM version of the HD Radio system is very different from the AM version. In the AM version, parts of the HD Radio signal are buried under the audio and in quadrature with the carrier. In addition, the AM audio bandwidth is narrowed to 5 kHz to accommodate a set of HD Radio subcarriers in the region of 5–10 kHz from the unmodulated AM carrier.
The FM HD Radio system makes no demands on the analog FM signal. In fact, the FM HD Radio signal is a separate entity, operating at the far reaches of the FM channel. There is no need to narrow the bandwidth of the analog channel, FM stereo operation is not affected, and the station can still operate ...