Return-Path: Received: (qmail 18018 invoked from network); 8 Nov 2001 07:00:03 -0000 Received: from unknown (HELO warrior.services.quay.plus.net) (212.159.14.227) by excalibur.plus.net with SMTP; 8 Nov 2001 07:00:03 -0000 X-Priority: 3 X-MSMail-Priority: Normal Received: (qmail 12119 invoked from network); 8 Nov 2001 06:59:55 -0000 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Received: from unknown (HELO post.thorcom.com) (212.172.148.70) by warrior.services.quay.plus.net with SMTP; 8 Nov 2001 06:59:55 -0000 Received: from majordom by post.thorcom.com with local (Exim 3.33 #2) id 161j2D-0002sE-00 for rsgb_lf_group-outgoing@blacksheep.org; Thu, 08 Nov 2001 06:51:33 +0000 Received: from imo-r01.mx.aol.com ([152.163.225.97]) by post.thorcom.com with esmtp (Exim 3.33 #2) id 161j2C-0002s9-00 for rsgb_lf_group@blacksheep.org; Thu, 08 Nov 2001 06:51:32 +0000 Received: from WarmSpgs@aol.com by imo-r01.mx.aol.com (mail_out_v31_r1.8.) id l.ce.1d0aca71 (3976) for ; Thu, 8 Nov 2001 01:50:49 -0500 (EST) From: WarmSpgs@aol.com Message-ID: Date: Thu, 8 Nov 2001 01:50:49 EST Subject: Re: LF: Re: Ringing Voltage on Telephone, boo-boo To: rsgb_lf_group@blacksheep.org MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 8bit X-Mailer: AOL 4.0 for Windows 95 sub 120 Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group Sender: I don't know how it is in Canada, but in the States, the 20Hz component is the only ringing voltage sent across the line to the telephone set, which can readily be confirmed by sticking a blocking capacitor and a bridging transformer acorss the line and looking at the result directly on an oscilloscope. The modulated audio frequency tones are sent from the switching office back to the caller, not to the recipient. Locally, the ringing voltage is 90V RMS, riding on the normal on-hook DC of about 50 volts. 73, John