The Cyber-Spy.Com Usenet Archive Feeds Directly
From The Open And Publicly Available Newsgroup
This Group And Thousands Of Others Are Available
On Most IS NNTP News Servers On Port 119.
Cyber-Spy.Com Is NOT Responsible For Any Topic,
Opinions Or Content Posted To This Or Any Other
Newsgroup. This Web Archive Of The Newsgroup And
Posts Are For Informational Purposes Only.
Subject: Re: How to check for a 50 or 75 ohm connector
Date: Sun, 22 Dec 2002 15:50:22 +0000
References: <3E053579.AFE0BFDF@sympatico.ca> <email@example.com> <firstname.lastname@example.org> <email@example.com>
NNTP-Posting-Date: Sun, 22 Dec 2002 21:41:34 +0000 (UTC)
User-Agent: tin/1.4.2-20000205 ("Possession") (UNIX) (Linux/2.4.19 (i686))
In sci.electronics.design Don Pearce wrote:
> The warnings are only for N Type - they use air dielectric on both 50
> and 75 ohms, and change impedance by pin diameter.
> Whether there was ever a time when 50 and 75 ohm BNC were not
> interchangeable, I'm not sure. But I have seen some very old kit that
> has BNCs up to the current dimensions.
There was a version of the "BNC" made by one manufacturer which had different
size centre pins and obviously failed to meet the real BNC spec, but it has
not been on the market for quite a few years this I suspect is where the
rumor started (ref. a long article about this in the back of the Canford
Note that (before digital video) it was common practice to use 50ohm
connectors in 75ohm systems because they were felt to be better mechanically
and the length of the connector was so short compared to the wavelength of
the highest frequency to be passed (about 5Mhz), this is no longer viable
with the advent of 270mb/s digital video....
New facitities should use the connector appropriate to the impeadence in use
but BNC is fully cross pluggable between 50 and 75 ohm systems.
** The email address *IS* valid, do NOT remove the spamblock
And on the evening of the first day the lord said...........
.... LX 1, GO!; and there was light.
Go Back To The Cyber-Spy.Com
Usenet Web Archive Index Of
The sci.electronics.design Newsgroup