2-Coil Tuning

Hi everyone,
             I was moved to conduct some scope experiments in the 
weekend due to the fact that my coils are working at peak performance
with considerably more Lp than is required to tune the primary to the
secondary fr. I used to think that the higher Lp was offsetting the
ion cloud/corona capacitance. I stil think that is an important oper-
ational mechanism, but something else also happens.
     With the coils tuned to the same frequency and coupled to a 
working degree (say about 0.1 or so), the double-humped frequencies
are around equal amplitude. But by lowering the primary frequency
beyond this, the higher of the two split frequencies diminishes in 
amplitude considerably while at the same time, the lower of the
frequencies rises in amplitude. It seems that by so tuning, the coil 
output is tending to single frequency operation at the lower of the 
two split frequencies with a much greater concentration of energy at 
just one frequency.

Interesting I thought,