RE: [SI-LIST] : Zo Choices & Why

About this list Date view Thread view Subject view Author view

From: Hassan Ali (hali@nortelnetworks.com)
Date: Tue Jan 02 2001 - 11:39:22 PST


This will help.

http://www.sigcon.com/articles/edn/why50.htm

Hassan.

-----Original Message-----
From: Chris Padilla [mailto:cpad@cisco.com]
Sent: Tuesday, January 02, 2001 2:08 PM
To: si-list@silab.eng.sun.com
Subject: [SI-LIST] : Zo Choices & Why

Hello Group and a Happy New Year to all!

My questions revolves around why, for instance:

(1) 50-ohms is the choice for instruments?

(2) 75-ohms is the choice for CATV/Satellite?

(3) 100-ohms is the choice for Ethernet?

(4) 28-ohms is the choice for Rambus?

(5) Any other "standards" I've left out? (300-ohms for VHF, UHF?)

I've read various things in the past explaining this but I have lost the
link nor can find original posts describing this.

I recall it being related to "What is the goal of the particular signal I
wish to transmit?" For CATV, it is picture quality over distance and I
think 75-ohms had the least amount of attenuation for the given
cable. 50-ohms for intruments was deemed "quietest" or something like that.

Anyone have the reasons?

Thanks----->Chris

**** To unsubscribe from si-list or si-list-digest: send e-mail to
majordomo@silab.eng.sun.com. In the BODY of message put: UNSUBSCRIBE
si-list or UNSUBSCRIBE si-list-digest, for more help, put HELP.
si-list archives are accessible at http://www.qsl.net/wb6tpu
****

**** To unsubscribe from si-list or si-list-digest: send e-mail to
majordomo@silab.eng.sun.com. In the BODY of message put: UNSUBSCRIBE
si-list or UNSUBSCRIBE si-list-digest, for more help, put HELP.
si-list archives are accessible at http://www.qsl.net/wb6tpu
****


About this list Date view Thread view Subject view Author view

This archive was generated by hypermail 2b29 : Tue May 08 2001 - 14:30:32 PDT