Customer has LDC1612 with your 46mm 50turn coil on Ch0 and it runs at ~1.56Mhz open to air. I have no capacitor on the coil board but connect with a 2’ RG58U cable and SMA connector mounted on the coil board so this adds probably 50-75pf:
The coil design tool says it should run at 1.8Mhz which I get close to if I use 100pf – 75pf is used here:
I wanted to see how this coil performed using my VNA (Keysight FieldFox) but It comes up with quite a different resonance point ~13.5Mhz (the marker is at 12.04Mhz), despite having a 3’ RG58U cable:
Why is this off by almost 10x?
Regards,
Mark
