7000 14"D coil, how it works...

I'm asking about how the 14" DOD design works from an electrical perspective, this is not about the shaft system.

I've been trying to find more info on this, does anyone know mode about the design of the coil?

A little bit on the coil here , Coil info. at about the 3 minute mark

https://www.youtube.com/watch?v=fZ0Bts6_axQ

I guess that without knowing what type of signal the detector is transmitting it is difficult to say how the coil is set up to work.
If it was a simple VLF then one TX and two RX windings could be made to add the receive signals in each winding together thereby making an apparent 14 inch diam coil detect as deep as as say a 20 inch DD on large targets but small targets would produce a distinct double tone rather than one combined signal. That is about as simple as my brain can operate at the moment while it is still full of shingles.