X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Wed, 04 Mar 2009 13:34:18 -0500 Message-ID: X-Original-Return-Path: Received: from smtp.perigee.net ([166.82.201.14] verified) by logan.com (CommuniGate Pro SMTP 5.2.12) with ESMTPS id 3526881 for lml@lancaironline.net; Wed, 04 Mar 2009 11:09:41 -0500 Received-SPF: none receiver=logan.com; client-ip=166.82.201.14; envelope-from=jschroeder@perigee.net Received: from john-study-2.perigee.net (dsl-208-26-41-171.perigee.net [208.26.41.171]) (authenticated bits=0) by smtp.perigee.net (8.14.1/8.14.1) with ESMTP id n24G8vaj024224 for ; Wed, 4 Mar 2009 11:08:58 -0500 X-Original-Date: Wed, 04 Mar 2009 11:08:54 -0500 X-Original-To: "Lancair Mailing List" Subject: Re: [LML] Re: TruTrak autopliot and RF From: "John Schroeder" Content-Type: text/plain; format=flowed; delsp=yes; charset=iso-8859-15 MIME-Version: 1.0 References: Content-Transfer-Encoding: 7bit X-Original-Message-ID: In-Reply-To: User-Agent: Opera Mail/9.64 (Win32) Chris - We used the same items as did Steve. They come in various capacitance and according to the chart on the Amphenol website, 50 pico farads would capture the com band frequencies. The principle is that each pin has a capacitor between the top of the pin (input) and ground (case) to shunt rf energy to ground. We put one on between the connector and the tray and also on each of the servos. Our com antenna #2 was in the starboard wall of the baggage compartment (ES) and it also had an effect on the EFIS. We went to an external com antenna on the belly as #1 and made the one in the vertical stab #2. We also put baluns on each of the power cables (fat wires) where they interfaced to the panel and then on the feeder cables to the busses. This solved most all of the RF problems - except for the Ray Allen trim indicators. They still dim when we transmit. We also performed the installation test for RF prescribed in the Garmin GNS 480 Installation Manual. We had no RF interference with the GPS. Allied Electronics/Electric also has a product similar to the Amphenols. I ordered one to try in case the Amphenols didn't work. So, I don't know its effectiveness. Hope this helps. John On Wed, 04 Mar 2009 08:13:24 -0500, Steve Richard wrote: > I used this and it helped: > http://www.vonero.com/index.php?/showproduct/853439 > > Steve Richard > > Chris Zavatson wrote: > A recent upgrade to more powerful com radios has introduced a bit of an > undesirable problem with the Trutrak autopilot. When the auto pilot is > engaged and the #2 radio is keyed, serious pitch oscillations occur.