Dave, first apologies, I have not read all of the thread, but I am not sure of the Q of the transmitter coil. The unloaded Q of the output circuit should be as high as possible to minimise its loses. The loaded Q for transmitter tank circuits is normally designed to be about 10. This leads to loses in the tank circuit to be 1- (Qu - Ql)/Qu. with a Qu of 100 and a Ql of 10 = 1-(100-10)/100 = 10%. With your loaded Q of 50, the losses are 50%. Also a lower loaded Q leads to lower currents and voltages.