TIL a bad coax connector can look perfect but still cause a 4 hour delay

I was chasing a weak VHF signal on a Citation, swapped the radio and antenna, and finally found the BNC connector on the cable run had a tiny crack in the center pin insulator you could only see with a magnifier. Has anyone else had a simple connector turn into a half day hunt?

3 comments

3 Comments

jackson.wesley2mo ago

Yeah, that's a BNC for you. I've seen the same hairline crack in TNC connectors too, it's not just a BNC thing.

the_diana2mo ago

Ever spend hours on a problem that tiny?

green.mason1mo ago

Actually it's kind of the opposite with BNC connectors. The hairline crack thing is way more common in TNC connectors because of how the threads are machined. BNC connectors are bayonet style, they lock in with a twist and don't have the same stress points. I've swapped out enough of both to notice the difference. TNC's fine thread can chip or crack if you overtighten it even a little, but BNC usually just pops loose if there's an issue. Not saying BNC never cracks, just that it's not the same problem.