Return-Path: Received: from mtiwmhc27.worldnet.att.net ([204.127.131.52]) by ns1.olsusa.com (Post.Office MTA v3.5.3 release 223 ID# 0-64832U3500L350S0V35) with ESMTP id com for ; Tue, 25 Apr 2000 01:23:45 -0400 Received: from ckrouse_ra.spk.hp.com ([12.73.163.222]) by mtiwmhc27.worldnet.att.net (InterMail vM.4.01.02.39 201-229-119-122) with SMTP id <20000425052930.KETM6491.mtiwmhc27.worldnet.att.net@ckrouse_ra.spk.hp.com> for ; Tue, 25 Apr 2000 05:29:30 +0000 Message-ID: <001001bfae75$fec08620$dea3490c@ckrouse_ra.spk.hp.com> Reply-To: "Curtis Krouse" From: "Curtis Krouse" To: Subject: Fw: SA-005 Transponder/DME Antenna Date: Mon, 24 Apr 2000 22:20:37 -0700 X-Mailing-List: lancair.list@olsusa.com Mime-Version: 1.0 <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>> << Lancair Builders' Mail List >> <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>> >> There are a couple of things that you have to consider when using an antenna for two units. If they are both receiving units....it's no problem using a splitter. A splitter will decrease the strength of the signal about 3db (approx. 50%). If you are going to use an antenna for units that both transmit and receive, then you need to use a diplexer or duplexer and the signal when transmitting should be attenuated at least 20db or more to ensure isolation between the receiving unit when the transmitting unit is in transmission. It would be safer, in my opinion, because of the fact that the transponder is transmitting a lot, to use a separate transponder antenna. Make sure that the cockpit area is shielded from the microwave transmission of the transponder. This can be done by bonding aluminum foil on the bulkheads between the seating area and the antenna location. Microwave is not a good thing to be bombarded with continually......just think about microwave popcorn. Our (plastic) airplanes don't provide any shielding from the transponder transmission. Curtis Krouse N753K >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> LML website: http://www.olsusa.com/Users/Mkaye/maillist.html Builders' Bookstore: http://www.buildersbooks.com/lancair Please send your photos and drawings to marvkaye@olsusa.com. >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>