STX 165 :: What is the SMA Connector? Nov 28, 2014 | What is the SMA Connector? 1 Comment admin on November 28, 2014 at 6:20 pm The SMA connector is a standard aviation industry connector. If you do not have a SMA crimper it is suggested that you contact a local avionics shop. Stein Air (www.steinair.com) fabricates harness to your custom length. You can also use an SMA to BNC adapter but you might experience some dB drop in signal.