Build a High-Energy Radio Frequency bug killer

The project is rather simple and pretty straight forward. I would like to get a High-Energy Radio Frequency bug blaster (aka HERF gun - [login to view URL]) to kill bugs in wood beams. Therefore it's about modifying a microwave oven to get rid of part of the frame (where things are cooked), keep the magnetron, mount a basic wave guide metal frame at the end of the magnetron, and having a remote on/off button. Off course an old but still powerful mw oven could do the job.