---------------------------------------------------------- RotaxEngines-List Digest Archive --- Total Messages Posted Sun 10/07/07: 1 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 10:03 PM - [Fw: Re: Re: 912ULS and XCOM760 Problem] (Silvano Gai) ________________________________ Message 1 _____________________________________ Time: 10:03:37 PM PST US From: Silvano Gai Subject: [Fwd: Re: RotaxEngines-List: Re: 912ULS and XCOM760 Problem] FYI -- Silvano -------- Original Message -------- Subject: Re: RotaxEngines-List: Re: 912ULS and XCOM760 Problem From: Michael Coates CC: References: <1191659095.m2f.138450@forums.matronics.com> <4707C244.508@ip6.com> Hello Silvano, thank you for forwarding on this information from the Rotax group. I just tried to reply directly but because I am not a member of this group it won't allow me even though I am a member of the AeroElectric one ??. If possible are you able to forward on this reply on my behalf ?. Firstly, the Euro foxes have had a problem for a long time with incorrect wiring which has been plaguing several of the dealers around the world. Euro Fox did not install the electrolytic capacitor which is a requirement of the Rotax factory when using their regulator. Finally the dealers that were having problems convinced euro Fox to install the electrolytic capacitor but unfortunately they did not put it in the right position so that was no protection in the circuit. As mentioned above is a requirement of Rotax and I quote the installation manual _"for flawless operation of the regulator and electrolytic capacitor must be installed"_, basically what they are saying is our regulator works "most" of the time but when it doesn't work you must install and electrolytic capacitor to protect your Avionics from damage. This is fine if it is installed in the correct position but if it is not installed in the correct position it simply will not work. The best option however is to replace the Rotax regulator with the PowerMate regulator which has been offering faultless performance for many of our customers for the last five or six years. Please see the following link for our suggested method on wiring up a typical light sport aircraft http://www.mcp.com.au/xcom760/faq/wiring-aircraft.pdf We receive a lot of feedback from customers that are having problems with their radio and occasionally locking up, this is a direct result of the radio going into safe mode after it has received voltage irregularities, this could include voltage spikes such as over voltage or also brownouts. An electrolytic capacitor fitted in the correct position will eliminate this problem. The Euro Fox dealer in Australia now fits the electrolytic capacitor in the correct position and no longer has any problems whatsoever. We have customers with more than 1800 hrs flying behind the XCOM with Rotax 80 hp engines without any problems at all but they have the electrolytic capacitor fitted in the correct position. With regards to the radio going into safe mode, what happens is if the radio experiences any voltage irregularities it will go into safe mode for approximately 30 seconds upon which it checks again and if everything is fine and then restarts normal operation. During this procedure the radio is still able to receive but it will not transmit and none of the buttons will work hence the reported lock-up problem. This is a concern to some of our customers so some time ago we implemented a flashing screen where the screen turned on and off once per second if the radio ever went into safe mode. Further to this we have now added some additional parts to our radio to also help eliminate the weaknesses with the Rotax regulator. The XCOM radio does however exceed the required TSO DO-160 standards for voltage stability and it is the Rotax regulator which is at fault in this case, because our radio is used in many Rotax installations we have adapted our design to be more stable when working with a Rotax regulator. (NOTE: There seems to be a peak in Rotax regulator failures in the last four months based from reports of the different dealers selling our product, so it may be that Rotax is starting to have a problem with some of the new installations) One of the things that can happen with a radio over time is that it can be damaged by ongoing voltage instability or by high aerial VSWR and that may be why you put a new radio in it starts working again but my guess is that the same radio working now will probably not be working in some 30 hour's time because it will go on to be damaged just like the one you have just taken out. Of note I spent all of last Thursday down with a large aircraft importer and manufacturer who was having trouble with four XCOM radios that would start out perfect and then deteriorate over five hours until they were unusable and transmission was no longer being produced. Even though they had reassured me a hundred times that the installation had been checked out in every respect when I got there and put an antenna analyser onto the aircraft it was shown the have and aerial VSWR of 7:1 !! and this explains the problems with transmission. No radio can it be expected to last at more than 3:1. Fitting a new aerial and grounding it correctly brought the VSWR down to under 2:1 across the entire aviation band and I expect that the radio will now go on to perform faultlessly the many years to come. I don't know the exact figure that I would say 99% of our service is based around bad installation, incorrect materials used or simply lack of knowledge by the aircraft owner who is trying to be a jack of all trades and master of none as he builds his aircraft. We have radios turn up the service that are reported as the intercom has failed. As soon as we turn the radio on and adjust the intercom squelch from 63 which is as maximum value back down to a more sensible 20 the radio suddenly works and it is normal for us to get two or three of this type of " failure" each week. This is something we are addressing on our website to try and educate our customers and as such have produced a wealth of material for the standard home builder including some of the following guides..... Aerial dummies guide http://www.mcp.com.au/xcom760/education/XCOM-Aerial-Dummies-Guide.pdf How to make an aircraft harness http://www.mcp.com.au/xcom760/education/education.html#Anchor-Ho-25294 How to terminate a BNC connector http://www.mcp.com.au/xcom760/education/education.html#Anchor-Ho-10102 How to solder http://www.mcp.com.au/xcom760/education/education.html#Anchor-Ho-63324 Etc, etc..... Just reviewing the information in the e-mail again it is only necessary to fit one electrolytic capacitor to an aircraft but it must be installed in the correct position as per hour suggested layout and the sport aircraft wiring guide http://www.mcp.com.au/xcom760/faq/wiring-aircraft.pdf As always we make ourselves available to any of our customers who are having difficulties and most of the time these can be resolved over e-mail by returning the radio to the factory defaults and checking the installation which includes all of the harness wires and also the aerial VSWR. I often say to my customers it is a bit like buying a new TV and new roof mounted TV aerial. It's easy to put the TV in the lounge room and expect it to work but because you don't have the equipment to tell you which direction you need to point the aerial to get the best reception you will get very ordinarily reception at the best of times. Somebody however with the correct equipment can point the aerial directly at the tower within a few seconds and provide you with beautiful clear results. It is the same with aircraft installations, the aerial has a major effect on the installation as does the wiring harness, just like the TV example above unless you have the aerial properly tuned in good quality cable between the aerial and your new TV you will experience the same frustration and poor results as you would in the aircraft. As always, please come back to me with any additional questions you may have so that we can personally assist our customers in getting the best from their equipment. Kind regards Michael Coates XCOM Avionics ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message rotaxengines-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/RotaxEngines-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/rotaxengines-list Browse Digests http://www.matronics.com/digest/rotaxengines-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.