From: Ian Walker
Subject: Re: How to check for a 50 or 75 ohm connector
Date: Sun, 22 Dec 2002 21:31:08 +0000
NNTP-Posting-Date: Sun, 22 Dec 2002 22:01:01 +0000 (UTC)
User-Agent: Turnpike/6.02-U ()
In article <email@example.com>, DarkMatter
>On Sun, 22 Dec 2002 15:15:52 +0000, Ian Walker Gave
>>Wrong! Whilst 50 and 70 ohm N (BNC) type connectors are both N (BNC)
>>type they are incompletely described by calling them N (or BNC) type.
>>You must also specify the impedance for correct electrical (and
>>mechanical in the case of N type) performance, the type of cable
>>providing it is suitable for the connector is irrelevant (i.e. you can
>>have RG-174 on one side of an N system and RG-203 on the other).
> You prove in your own statement that it IS indeed the cable that is
>the determining factor.
Only in that the properties of the system determine the type of cable
that must used (RG-174, RG-58, RG-203, Su-104, etc.), both the cable and
the system determine the connector that must be used (BNC, N, C, K,
PC3.5, PC7, 2.4, 1.0, etc.). If the connector side is not designed to
have the same impedance as the cable then you will get a reflection from
If you have only got a bag of unidentified plugs you will have to
measure the inner and outer diameters and, along with a guess at the
dielectric calculate the impedance.