X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from [66.174.76.206] (account marv@lancaironline.net) by logan.com (CommuniGate Pro WebUser 4.3.6) with HTTP id 1055555 for lml@lancaironline.net; Wed, 13 Jul 2005 17:52:41 -0400 From: "Marvin Kaye" Subject: Re: [LML] Mode C To: lml X-Mailer: CommuniGate Pro WebUser Interface v.4.3.6 Date: Wed, 13 Jul 2005 17:52:41 -0400 Message-ID: In-Reply-To: <20050713180806.B948E164037@ws1-4.us4.outblaze.com> References: <20050713180806.B948E164037@ws1-4.us4.outblaze.com> MIME-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1"; format="flowed" Content-Transfer-Encoding: 8bit Posted for "Ron Galbraith" : This is a very basic expanation, but in short, a transponder works with 15 pulses. 2 framing pulses for timing, and 13 others between the framing pulses. If you have mode C, then these pulses are shared between the code being displayed such as 1200, and the altitude. To get that altitude information to the transponder, you must have a separate Mode C encoder. These are either a blind encode, or encoding altimeter where the actual altimeter sends the info to the transponder. If you aren't having a problem with the transponder code getting to ATC, then the problem probably isn't the transponder, but rather the encoder or the wiring between the transponder and the encoder. Since the problem is intermittant, then the best guess problem is the encoder itself. Ron Galbraith LNCE - N5ES > Can someone describe the intricacies of Mode C?