lml@lancaironline.net Mailing List Archive

<<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>> << Lancair Builders' Mail List >> <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>> Jim Cameron Wrote: >The Ritchie compass looked very attractive when I was designing >my panel -- new technology, no precession, light weight, and quite >inexpensive (about $260, as I recall). Sound familiar? We have talked about lots of quite inexpensive and high performance avionics..... >After some flight hours with it, however, I elected to replace it >with the old-tech RC Allen model. You can learn from Jim's experience, or you can try it for yourself. The choice is yours. Maybe you have the power to claim an exception to the laws of physics & economics. You will never know till you try. >when you key the mic to transmit on your COM, the Ritchie compass >goes nuts (along with the E.I. fuel gauge). Seems that neither of these >instruments like stray RF. Before I continue, let me do the usual disclaimers regarding my affiliation with Sierra Flight Systems. Brent Regan and I have designed the hardware for the Sierra Flight Systems' EFIS products and are working on the certification program for the EFIS. Just a few days ago I was reviewing the costed bill of materials for the custom designed EFIS board and was surprised at the significant cost of components whose sole purpose in life is to deal with stray RF, both the kind that you get when you key the mike and the kind you get from a bolt of lightening. Obviously I can not talk about specific numbers, but suffice to say that SFS is spending more on components to handle RF than some competitors may be spending on their entire hardware. That is the difference between hardware that is designed specifically for the aviation environment versus slapping together hobbyist components into a "new technology, light weight, state of the art, quite inexpensive" system. You can have low cost hardware or you can have reliable hardware. You can have either, but not both. As I said earlier, the choice is yours. Hamid LML website: http://members.olsusa.com/mkaye/maillist.html LML Builders' Bookstore: http://www.buildersbooks.com/lancair Please remember that purchases from the Builders' Bookstore assist with the management of the LML. Please send your photos and drawings to marvkaye@olsusa.com.