Whilst browsing YouTube, I came across this brilliant channel explaining how FM works, and in particular how stereo FM works in broadcast transmitters by Drew Kirkman.

The channel is called “Broadcast Blueprint” and the program is at How FM Radio Works: A History and Exploration of Frequency Modulation

None of this is my work, I simply watched the program, however, for effect, the image is a screenshot of the work from this channel.

Drew’s website is at: https://broadcastblueprint.com/