---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Fri 12/10/21: 9 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 06:16 AM - DIY VOR/ILS diplexer? (Charlie England) 2. 06:49 AM - Re: DIY VOR/ILS diplexer? (Eric Page) 3. 07:14 AM - Re: DIY VOR/ILS diplexer? (Eric Page) 4. 07:35 AM - Re: DIY VOR/ILS diplexer? (Eric Page) 5. 08:41 AM - Re: Re: DIY VOR/ILS diplexer? (Robert L. Nuckolls, III) 6. 10:13 AM - Re: DIY VOR/ILS diplexer? (user9253) 7. 12:13 PM - Re: Re: DIY VOR/ILS diplexer? (Charlie England) 8. 12:43 PM - Re: DIY VOR/ILS diplexer? (Eric Page) 9. 01:01 PM - Re: DIY VOR/ILS diplexer? (Eric Page) ________________________________ Message 1 _____________________________________ Time: 06:16:38 AM PST US From: Charlie England Subject: AeroElectric-List: DIY VOR/ILS diplexer? Good morning, A friend needs to install either an ILS antenna, or acquire a diplexer to split his existing VOR antenna signal to feed both the VOR and ILS inputs on his Garmin 530. A diplexer would obviously be lighter & easier to install, but off-the-shelf models tend to cost more than an antenna. I thought that the Aeroelectric site had a circuit diagram for rolling your own diplexer, but I haven't been able to find it. Can anyone help with this? Thanks, Charlie ________________________________ Message 2 _____________________________________ Time: 06:49:03 AM PST US Subject: AeroElectric-List: Re: DIY VOR/ILS diplexer? From: "Eric Page" Here's a program that will design the filter elements for a diplexer... http://www.tonnesoftware.com/elsie.html ...and here's a video by Alan Wolke (W2AEW) explaining diplexers and demonstrating one that he built. https://www.youtube.com/watch?v=wv79DSqVi9w Read this topic online here: http://forums.matronics.com/viewtopic.php?p=505209#505209 ________________________________ Message 3 _____________________________________ Time: 07:14:47 AM PST US Subject: AeroElectric-List: Re: DIY VOR/ILS diplexer? From: "Eric Page" Or, if you don't mind laying out your own board, Mini-Circuits sells pre-made band-pass filter elements that are specifically designed for the VOR/ILS and GS frequency bands: https://tinyurl.com/mtp67ycw+ https://tinyurl.com/yc2zt4d8+ Read this topic online here: http://forums.matronics.com/viewtopic.php?p=505210#505210 ________________________________ Message 4 _____________________________________ Time: 07:35:27 AM PST US Subject: AeroElectric-List: Re: DIY VOR/ILS diplexer? From: "Eric Page" Someone with more knowledge of RF wizardry could tell us whether this would work, but another possibility occurs to me. Put a simple tee splitter on the antenna feedline, then in-line low pass and high pass filters feeding the VOR/LOC and GS receivers, respectively. You would need some adapters to accommodate the filters' SMA connectors. https://www.digikey.com/short/vf3vrnwj https://www.digikey.com/short/hm2t9wtd Read this topic online here: http://forums.matronics.com/viewtopic.php?p=505212#505212 ________________________________ Message 5 _____________________________________ Time: 08:41:48 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Re: DIY VOR/ILS diplexer? At 09:14 AM 12/10/2021, you wrote: > >Or, if you don't mind laying out your own board, Mini-Circuits sells >pre-made band-pass filter elements that are specifically designed >for the VOR/ILS and GS frequency bands: > >https://tinyurl.com/mtp67ycw > >https://tinyurl.com/yc2zt4d8 > You need to remove the + signs from those links for them to work. Those would take all the uncertainty and post fabrication verification concerns. I've built those from discrete components but had access to test equipment to make sure they were working as desired. But then, these are experimental airplanes where you can do in-flight performance checks to see if your own design goals are met. Some pretty 'soft' antenna systems have been found adequate to task. On the other side of the coin, what's your labor worth? There are numerous offers on eBay for about the same price as the Mini-Circuits devices . . . they're all packaged up and ready to go. https://tinyurl.com/yckhtnet Bob . . . Un impeachable logic: George Carlin asked, "If black boxes survive crashes, why don't they make the whole airplane out of that stuff?" ________________________________ Message 6 _____________________________________ Time: 10:13:20 AM PST US Subject: AeroElectric-List: Re: DIY VOR/ILS diplexer? From: "user9253" Jim Weir has written articles about splitting an ILS signal from a VOR antenna. https://www.kitplanes.com/tall-transmission-tales/ Note that his diagram shows an inductor but the text explains that a 10-picofarad capacitor with straight leads has enough inductance without a separate coil. Below by Bob posted years ago: Actually, you can fabricate a nifty antenna just from coax cable. In this case, you clean off the outer jacket of your feedline about 11". If it's a double shielded coax, strip of the outer layer of shield too. Pull center conductor out of the remaining shield as illustrated here: http://www.aeroelectric.com/articles/shldwire/shldwire.html Stretch the center conductor and remaining braid out into a dipole and trim each to 8.5" per side. Glue to 1/4" wood or plastic dowel 17" long. Just spot it in a few places to fixture it on the dowel. Then put pieces of heat shrink over each leg of the dipole to "dress it up". This technique eliminates the process-sensitive and never pretty junction between antenna elements and the feedline. It's all one piece. Bob -------- Joe Gores Read this topic online here: http://forums.matronics.com/viewtopic.php?p=505218#505218 ________________________________ Message 7 _____________________________________ Time: 12:13:07 PM PST US Subject: Re: AeroElectric-List: Re: DIY VOR/ILS diplexer? From: Charlie England Thanks for the ideas. Ebay is certainly the best option, but I've passed on the various possibilities to my friend. Charlie -- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus ________________________________ Message 8 _____________________________________ Time: 12:43:26 PM PST US Subject: AeroElectric-List: Re: DIY VOR/ILS diplexer? From: "Eric Page" nuckolls.bob(at)aeroelect wrote: > You need to remove the + signs from those links for them to work. The + sign is a documented feature of the TinyURL service. It causes their server to display a preview screen where the user can see the URL hes being taken to, before actually going there. Its intended as a safety measure, to reassure users that theyre not being sent to a malicious website by an obfuscated hyperlink. Read this topic online here: http://forums.matronics.com/viewtopic.php?p=505222#505222 ________________________________ Message 9 _____________________________________ Time: 01:01:57 PM PST US Subject: AeroElectric-List: Re: DIY VOR/ILS diplexer? From: "Eric Page" user9253 wrote: > Jim Weir has written articles about splitting an ILS signal from a VOR antenna. I knew I had seen that recently! Kitplanes republished that idea in the Dec 2021 issue, and Jim showed it built as a stand-alone device. That part of the article begins at the bottom of page 2 in the attached PDF. Read this topic online here: http://forums.matronics.com/viewtopic.php?p=505223#505223 Attachments: http://forums.matronics.com//files/potpourri_153.pdf ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message aeroelectric-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/AeroElectric-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/aeroelectric-list Browse Digests http://www.matronics.com/digest/aeroelectric-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.