---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Sat 07/06/19: 2 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 05:47 PM - Re: Balun article (Robert L. Nuckolls, III) 2. 08:10 PM - Y splitter (Argonaut36) ________________________________ Message 1 _____________________________________ Time: 05:47:09 PM PST US From: "Robert L. Nuckolls, III" Subject: AeroElectric-List: Re: Balun article At 10:26 AM 7/6/2019, you wrote: >AV-12 ' RAMI > > >AV-12 ' RAMMI > > > > >This is the antenna > >Sent >from Yahoo Mail on Android Now that's a mystery . . . One would think that RAMMI knows what they're doing. 20" elements do not conform to legacy antenna design rules . . . but we don't know what matching components might be included inside their mounting base. It would be cool to put an antenna analyzer on the antenna and see what it looks like. The pictures I can see of the RAMMI coax cable with integral balun suggests that they've fabricated a design like this on the end. I've seen this design in documentation for aviation radios . . . in fact, we find it in AC43-13 dated 2008 and . . . Emacs! in this illustration taken from the installation manual circa 1949 for a Lear LTRA6 transceiver Emacs! Where Item 7 is called out as a 63184-02 Transmission Line Assembly but without further details as to how it's constructed. The design is echoed on numerous websites as an 'aviation antenna balun'. Two flies in the ointment: First the callout for "1/4 wave" is not defined. Free air or in coax. Second, the balun is noted in an article by a competent observer of things electronic where he states, "Lab tests do not confirm that this balun works." Emacs! Okay then . . . when I'm ready to put the signal generator on Jim Weir's dual band ELT antenna to investigate common mode chokes, I'll be able (1)to confirm/deny the functionality of this design (2) reconfirm functionality of the Pawsey Stub balun described in many articles and echoed on my website and (3) see if a ferrite core common mode choke would be a less fussy way to mate coax to the cat-whisker vor antenna. In the mean time, know that back in the dark ages, Cessna Pawnee plant fiddled with various baluns for the whiskers . . . they even might have tried the design above. I do know that a whole lot of airplanes were built with coax attached directly to the antenna with NO balun . . . VOR signals are strong, distance from aircraft to vor stations at the changeover point along published airways is never so far that a really lousy antenna wouldn't work. I think Cessna had more trouble with process and manufactured fragility than with radio performance . . . they quit using them entirely for a time. That still leaves the question about your RAMMI antenna with 20" whiskers. If you just hooked your feedline directly to the RAMMI antenna, chances are you'll never know the difference. Bob . . . ________________________________ Message 2 _____________________________________ Time: 08:10:41 PM PST US Subject: AeroElectric-List: Y splitter From: "Argonaut36" I was wondering if the practice of twisting 2 wires together and crimping the resulting wire in a ring terminal can be considered acceptable, even for standard certificate airplanes, for making a Y splitter. If so, assuming that 2 wires to be twisted together are size 20#, should a red or blue ring terminal be used? Thanks Read this topic online here: http://forums.matronics.com/viewtopic.php?p=490084#490084 ------------------------------------------------------------------------------------- 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.