Drive a piezo at 6.78mhz

[ryba7]

I Tried and obtained this. Yellow is real, purple imaginary. The resonance is at the middle of the screen , when the two graphs mingle ?

[Marco]

Resonance is supposed to be where the reactance is 0 and the impedance is minimum, anti-resonance is supposed to be where reactance is zero and impedance is maximum. Due to imperfections zero phase and minimum/maximum resistance might not exactly overlap.

N7PJ was suggesting driving it at anti-resonance.

Bizarrely my guesstimates at the equivalent circuit (100 mOhm Rs, 2 nF Cs, 10 nF Cp and whatever L is necessary for a given resonance frequency, 276 nH for 6.78MHz and 300 nH for 6.5 MHz) produce a near perfect 50 Ohm resistance at anti-resonance ... no matching needed whatsoever. Also dissipating the exact same power as the pi-match at resonance.

[ryba7]

That's why it didn't looked the same and the resistance was spiking up...
I forgot you can also use antiresonance...