A tiny crack in a coax connector cost me half a day | Avionics Technicians

Jenny Coleman · 2026-03-23T20:55:05.736096+00:00

I was finishing up a VHF comms check on a Citation last month and kept getting a weak signal. Everything tested fine at the box. I finally pulled the antenna and saw a hairline crack in the center pin insulator of the BNC connector, probably from overtightening. Replaced the whole pigtail and it cleared right up. Anyone else run into something like that where the fault was in the connector itself?

tara6236mo ago

Had a King Air with a similar issue last spring. That tiny crack in the SMA connector drove me nuts for a whole shift. Feels good when you finally spot it.

3

lucaslee6mo ago

Check the connector body for stress marks from a bad crimp too.

1

paigem456mo ago

Oh man, that's the worst. Found a cracked TNC on a nav antenna once, same deal. Tiny fracture you could barely see. @lucaslee is right about checking for crimp marks too, that's a solid tip. Spent hours on the radio test before I spotted it.

1