WR-42 Waveguide to Coaxial Adapters from Fairview Microwave are also known as waveguide to coax transitions. 2.92mm, SMA waveguide to coaxial adapters are in-stock and available for same day shipment. Fairview WR-42 Waveguide to Coaxial Adapters have a maximum frequency of 26.5 GHz and a max VSWR of 1.25. WR-42 Waveguide to Coaxial Adapters have a connector body material of passivated stainless steel.