RF Heater design recommendation

I am working with a project to design a Radio Frequency Heater by using class C power amplifier. However i am now crossing a problem with the abnormal voltage outcome and not so sure am i doing correctly with the feedback circuit. Wish someone can give me some advice and help.

This is the drain voltage from the mosfet

This is the feedback voltage

This is the gate voltage

You have got V1 feeding directly via the transformer to the 50K load, is this what you want? The waveforms look about right.
Frank