Path: utzoo!attcan!uunet!zephyr.ens.tek.com!uw-beaver!cornell!umich!accuvax.nwu.edu!nucsrl!telecom-request
From: IZZYAS1@oac.ucla.edu (Andy Jacobson)
Newsgroups: comp.dcom.telecom
Subject: Re: A/A1 Control For Key Telephone Systems
Message-ID: <14092@accuvax.nwu.edu>
Date: 28 Oct 90 12:16:00 GMT
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X-Telecom-Digest: Volume 10, Issue 770, Message 5 of 10


In V10, #765, "Barton F. Bruce" <BRUCE@ccavax.camb.com> responds to
drears@pica.army.mil (Dennis G. Rears (FSAC)):

>If the A-A1 connection is broken BUT
>the current is still flowing from Tip to Ring, the line card knows you
>want to go on hold (things are in this state when you have the hold
>button bottomed). The card immediately switches a 135 ohm 5 watt
>(typical) resistor across T+R to simulate a phone off hook to hold the
>line up.

So, if that is all there is, where would this resistor be on a 400D,
400G or 400H card? Would it be possible to simply put a high Z or
xformer isolated source across it and create your own music on hold
circuit? That would certainly be alot cheaper and less trouble than
buying one of those adaptor kits that companys like Tellabs sells.