Total posts : 45366
Nice report on your model. I also modeled it using Electronics Workbench (a GUI for Pspice), but I did it a bit differently. I ran a Bode plot which shows the gain of the network vs. frequency and only saw one peak near 1600 kHz. You reported the impedance which may behave differently from the gain, but we both agree that the voltage will be maximized at the “tuned” frequency.
The equation I derived shows the effect you saw with the possibility of the numerator going to zero and the denominator going to zero at different combinations of the elements in the network. This “dual resonance” shows up in crystals and duplexers among other radio circuits.
Your split coil idea should work since you will have control over XL and C5/C23 for adjustment.
Keep up the good work and let us know how it works in practice.