About TNC Connectors
"Threaded Neill-Concelman". Designed as a screw-on version of BNC connector, TNC connectors have a 7/16 - 28 UNEF threaded coupling providing excellent vibration handling.
The connector is widely used due to good electrical performance and mechanical durability, and can often be found on Cisco HWIC 3G / 4G cards, Trimble UHF devices, and some SCADA / ICS / IIoT devices.
TNC series has a characteristic impedance of 50 Ω, however it is important to note that 75 Ω variations while uncommon do exist and are identifiable by the reduced amount of dielectric inside the interface.
While performance up to 11 GHz is possible with precision designs, typically commercial manufacturers will set a maximum operating frequency of 3 to 6 GHz.