# XTAL resonance increase the voltage

I have a 4Mhz crystal and i connect it in series between the function generator and the oscilloscope probe as shown below:

simulate this circuit – Schematic created using CircuitLab

However i don't know if this testing method for XTAL is true or not but to see if the crystal works or not i set the function generator on 5Vpp and start to increasing the frequency, i was expected to see some change in the output in 4Mhz, but just when the frequency reach 4MHz i find the voltage in the output become 50Vpp !

I know the resonance causes increasing the voltage but there are no Inductor in this case,

So i'm wondering why this happen without inductor?

I have simulated your probe with a 10M$$\\Omega\$$ resistor in parallel with 3pF. Crystal parameters from this page.