Path: utzoo!attcan!uunet!cos!ssr
From: ssr@cos.com (Dave Kucharczyk)
Newsgroups: sci.electronics
Subject: Re: Origin of the name "BNC" connector
Message-ID: <14337@cos.com>
Date: 27 Jan 89 19:41:13 GMT
References: <5770015@hpscdc.HP.COM> <2312@iscuva.ISCS.COM>
Reply-To: ssr@cos.UUCP (Dave Kucharczyk)
Organization: Corporation for Open Systems, McLean, VA
Lines: 20
Organization:Never

In article <2312@iscuva.ISCS.COM> jimc@iscuva.ISCS.COM (Jim Cathey) writes:

>Around here a TNC connector is a BNC with _two_ center pins (Twin NC?).  We
>of course are not necessarily right in calling them this.  If I had to guess
>I would say BNC meant 'BayoNet Coaxial', and that TNC was the Twin, or Twisted
>version of same.  Any takers?  Howabout someone with accurate information?


  Acording to the Amphenol catalog the connectors you are refering to 
are simply called 'Twin' coaxial connectors.  They come in different types
including UHF and BNC style.  BNC connectors are identical to TNC except
for the BNC uses 'a two stud bayonet lock coupling' while a TNC has
'a 7/16 - 28 threaded coupling'.  also the 'Twin' type connectors have 
a characteristic impedance of 78 or 90 ohms while 'BNC/TNC' have
a 50 ohm impedance.  All electrical specs between the 'TNC' and 'BNC'
are identical. (excluding cable sizes and other obvious differences of 
course).


dave