MIT successfully tested CCR’s internal converter for gyrotrons. The coupler converted 1.12 MW of RF power into an HE11 mode in corrugated waveguide inside the vacuum envelope of the gyrotron. This could potentially reduce the cost of gyrotrons by more than $100K and eliminate requirements for Mirror Optical Units, which reduces the cost of electron cyclotron heating systems approximately $500K per gyrotron. CCR presented these results at the RF Heating Technology Workshop in Santa Monica on September 7th. The MIT test performance is compared with the conventional multi-mirror Gaussian output converter in the accompanying figure.