Does anyone know why the distributed winding capacitance of a loop
antenna, or any inductor, degrades the efficiency?

It would seem that a loop antenna with 100pF of winding capacitance in
parallel with a external capacitor of 200pF would resonate at the
same frequency as a antenna with no winding capacitance and a external
capacitor of 300pF,but apparently that's not the case.

The best explanation I got was that winding capacitance represents
'low Q' and a external tuning capacitor represents ' High Q'

What is the difference between high and low Q, and why should a loop
antenna with no winding capacitance perform any better than one with
50% of the total capacitance in the windings? Where is the energy
loss?

Thanks,

-Bill