>Date: Thu, 6 Aug 1998 21:11:06 -0400 >From: "Victor L. Boersma" <[email protected]> > >Go to an old telephone store and buy any number of "C-4" ringers. Them is >the brass ones that used to sit in black telephones. REN stands for >"Ringer Equivalence Number" and 1 REN is the equivalent of 1 C-4 ringer. >(There was a Canadian proposal to change this to "Load Number" but the US >rejected it for old-times sake. Nobody is worried about how many C-4 >ringers are out there, what people want to know is what the maximum load >can be. However, as long as you insist on measuring things in the US, >based on the size of some extremities of a long dead British king, you >might as well go on with RENs.
This is very good advice. Some of the standards (can't remember which at the moment though) actually *call for* using Western Electric C4A ringers! (They have *two* brass bells on them, the ones with a single brass bell aren't C4A models.) I have found that I get different results when loading a CO or PBX line with C4A ringers, vs. using a resistive/capacitive load, because the ringers have induction as well. Some of the newer PBXs and CO line cards will "ring trip" due to the inductance! However, as most phones being made today don't have inductive ringers, this will not matter eventually. At the moment, there are tens of millions of the old WE 500/2500 and GTE 80E phones still in use which *do* have inductive ringers, of course. (There is a also a Korean manufacturer still making a near-perfect copy of the Western Electric 2500 phones. <g>) ________________________________________________________________ John Combs, Senior Project Engineer, ITS/TestMark Laboratories Email: [email protected] URL: http://www.testmark.com
