Re: Broadcast FM subcarrier decoding?

On 3/17/2013 9:48 AM, Alan Corey wrote: Hi Alan, Depending on where you live, there could be several subcarriers present. From your description I'm pretty sure you're referring to Sub Carrier Authorization (SCA) which has been mainly used for background music and an audio book reading service for the blind as well as other voice and data services. SCA uses 67 or 92 KHz subcarriers which can be seen on the composite FM signal. If you have a soundcard with sufficient bandwidth you can send the output of SDR# (in NBFM, 150 KHz mode) to another instance of SDR# *(sound card, DSB mode) using Virtual Audio Cable. My soundcard won't go high enough but here's a set of screen images from a system that can, where the various elements on the upper side of the FM channel center are annotated: http://img208.imageshack.us/img208/5922/fmspectrum.png The RDS (Radio Data System) or RDBS in the US digital data channel is easily seen at 57 KHz, The level of all these subcarriers is much lower than the stereo pilot so you'll need a strong signal for decoding. 73, Bob W9RAN