The stuff that Boomer has collected is now a really nice read, and info downloads! (And then some.)
http://boomerthedog.net/radio.htmlNow, probably the best on-line source for Carrier-Current AM operations. Not to mention AM C-QUAM Stereo via Part #15. Another good source is this page about James R. Cunningham,
http://lowpowerradio.blogspot.com/2015/11/low-power-am-circuits-of-james-r.html However, what I need to do is to make a good .PDF copy of the Ernest Wilson book - Carrier Current Techniques: The Wired Wireless Broadcasting, from 1979's Panaxis Productions. He shows you how you can build it all from the ground up.