At great risk, let me try this approach.

I have a 100 turn 2" diameter #18 gauge wire air core inductor. There
are 100 turns, so there is about 630 inches or 32 feet of wire in the
coil.

I have a Network Analyzer with port to port time delay measurement
capability. It measures coaxial cables very well, and even clip leads.

Cecil, please predict or guess the group delay of this inductor at 3.8
MHz. Tell us all what that group delay means for your wave theory.

Just come close, and I will tell you what it measures. I can even print
the plot just for you.

73 Tom