>>273972272
I'm one of those that failed extending it. This is not your normal Cable TV coaxial cable. It is more often found in Wi-Fi equipment. Like jnemesh says, it has to be SMA RP RG58. I tried with a 15 feet (3 m) long one, and it just didn't work at all: nothing was recognized. Have a look at this thread: https://www.reddit.com/r/Vive/comments/9n4upn/the_vive_wireless_kit_extending_the_antenna/