Do you guys remember the hayday of double side band?? Now compare it
to C4FM/digital


The old split systemTX/RX radio gear had a vfo and a spotter to
pinpoint the intended frequency!!

The TX spotter created a sample am carrier that allowed a null in
sound to sycronize the two TX/RX

Well this small am carrier gives C4FM the same ability to be
descrambled as it did SSB it provides the path through the
discriminator or does it not??I;-)