Stormwise model SWB-35 Shortwave Radio Stealth Wideband Antenna Adapter with Galvanic Noise Isolation. For use between 0.5 to 35 MHz. If you’ve avoided shortwave listening due to high hissing or buzzing noise levels, digital noise hash, the SWB-35 prevents house electronics RFI from getting into the antenna through the coaxial cable’s shield path.