Hello Mike
yes I did some research and found that it is done via a phase lock circuit, and when this is incorperated into the receiver, the receiver is called a Digital symthesized receiver.
I don't agree with all your terms though, or maybe I'm just misunderstanding them. When your talking about the "discriminator" or "Radio detector" do you meen the demodulator, halfwave rectifier? (AM signals)
Also when talking about AFC, the signal that is fed into it, is it the same signal used for AGC that is fed into the phase lock circuit that picks up when a signal is "centered"?