Path: utzoo!attcan!uunet!zaphod.mps.ohio-state.edu!tut.cis.ohio-state.edu!usenet.ins.cwru.edu!umich!accuvax.nwu.edu!nucsrl!telecom-request From: john@bovine.ati.com (John Higdon) Newsgroups: comp.dcom.telecom Subject: Re: A/A1 Control For Key Telephone Systems Message-ID: <14103@accuvax.nwu.edu> Date: 28 Oct 90 19:09:43 GMT Sender: news@accuvax.nwu.edu Reply-To: John Higdon Organization: Green Hills and Cows Lines: 23 Approved: Telecom@eecs.nwu.edu X-Submissions-To: telecom@eecs.nwu.edu X-Administrivia-To: telecom-request@eecs.nwu.edu X-Telecom-Digest: Volume 10, Issue 771, Message 6 of 11 Andy Jacobson writes: > 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. The resistor is easy to spot. It's the only five watt resistor on the card. Music on hold is nothing more than bridging audio across that resistor, usually with a transformer. But also bear in mind that you will have to provide isolation between lines; you wouldn't want two of your customers getting together while on hold and discussing an alternative to your goods or services. The isolation usually consists of the fact that each line is driven by a separate amplifier. This prevents audio from the caller from backing up through the MOH system and being heard by other callers on hold. John Higdon | P. O. Box 7648 | +1 408 723 1395 john@bovine.ati.com | San Jose, CA 95150 | M o o !