Are BNC connectors still used for anything?

Been doing home theater for a while? You might remember the BNC connector that was used for component connections in the 2000s and before. It has been used for SD video and HD video, but it’s rarely seen in consumer electronics today. Is it dead?

First let’s talk about the BNC connector. The Bayonet-style Neill-Concelman connector was patented in the 1950s as a combination of the N(Neill) and C(Concelman) connector styles. While N-connectors are still around, the C connector is no longer used. The goal was to have a connector for TV use that connected easily but stayed connected, and to have a metal sheath over the center conductor (unlike the F connector that uses the center conductor as a point of contact.) This would make for cables that could be connected and disconnected easily but didn’t fall out. The center sheath would guarantee that the cable wasn’t damaged by repeated connections.

To call the BNC connector a success is an understatement. It took over the world of commercial broadcasting, replacing RCA connectors and UHF connectors in broadcast equipment. For a time it was even used for computer networks. Yet, today the BNC connector is used only for very specific tasks and isn’t often seen outside broadcast facilities.

There’s a simple reason for that: the design of the connector allows RF to leak out or leak in if the cable is used to carry a signal at a frequency higher than 2GHz. This means right away that satellite TV is out of the question and even some cable systems use those frequencies. Computer data needs to use those frequencies as well if the data rate exceeds 100Mbps.

For home use, the RCA connector has become the more common way to make a component connection because of the smaller size of the connector. It’s true that RCA connections are much easier to pull out by mistake but that’s not a huge issue at home like it is for commercial installations.

So, the BNC connector isn’t dead, it’s just faded out of use for consumers. It’s used for SDI data (high-bitrate uncompressed HD) in a studio setting all the time. It’s just not likely you’ll see one at home again.

About the Author

Stuart Sweet
Stuart Sweet is the editor-in-chief of The Solid Signal Blog and a "master plumber" at Signal Group, LLC. He is the author of over 8,000 articles and longform tutorials including many posted here. Reach him by clicking on "Contact the Editor" at the bottom of this page.