TNC Threaded Connectors Amphenol RF TNC Threaded Connectors are miniature, threaded weatherproof units with a constant 50Ω or 75Ω impedance that operate from 500MHz to 11GHz. A threaded coupling interface ensures the connectors will not de-couple in vibration-intensive applications. There are two types of TNC connectors: standard and reverse polarity. Reverse polarity is a keying system accomplished with a reverse interface. This ensures that reverse polarity interface connectors do not mate with standard interface connectors. Many TNC connectors are UL recognized under the component program and have undergone stringent testing from an independent laboratory.