Review on DHT Electronics 2pcs RF Coaxial Coax Adapter: SMA Male to BNC Female - Goldplated Connectors by David Stewart

I use BNC on all my 2m radios for easy switching between antennas. This is perfect for my TYT radio. I was concerned because the SMA connector is countersunk, but the outside diameter of this adapter is almost the same as the antenna. I don't know how this will affect the 390 waterproofing, but I plan to coil up a thin bead of RTV silicone. edge of the connector to be sure.