---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Sat 06/11/16: 3 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 12:25 PM - Re: Antenna grounding (Robert L. Nuckolls, III) 2. 01:13 PM - Re: Antenna grounding (Michael Lazarowicz) 3. 04:35 PM - Re: Antenna grounding (user9253) ________________________________ Message 1 _____________________________________ Time: 12:25:06 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Antenna grounding At 08:20 AM 6/10/2016, you wrote: >One other question if you cont mind.=C2 I am >using RG400 for my ADSB and with all this >antenna location I may have to add about 6 " to >the ADSB cable.=C2 Its already about 12 feet >long.=C2 This is just ADSB in so not >transmission.=C2 How much will I loose if I >extend the cable with a interconnect fitting >?=C2 I got into this long length because of the >transponder being in the back.=C2 6 inches? The losses added by 6" plus connector to an existing 12' run cable would be difficult to measure much less observe in practice. A 12' length of RG400 will toss off about 40% of your transmit/receive signals at transponder frequencies . . . http://tinyurl.com/hdphfdv . . . again, probably not enough to be observed in practice. But at Beech, we'd use something more like LMR-400 for a loss of about 15%. There are probably sellers on eBay that would custom assemble a cable for you. What model transponder are we talking about. I like to read the wordage in the manual associated with antenna locations. Bob . . . ________________________________ Message 2 _____________________________________ Time: 01:13:54 PM PST US From: Michael Lazarowicz Subject: Re: AeroElectric-List: Antenna grounding Hi Bob, I am not speaking of the Transponder antenna. Mine will bee around 40" long with RG400. What referring to is the ADSB inn on The Garmin GRT39.remote I does not specify or give any antenna lengths. max or minimum. Teh RV8 bottom make mounting all this stuff 2 Comm antennas one transponder antenna and on ADSB Antenna. Basically Garmin wants them all 3feet or better apart. Since I mounted the transponder box itself a GTS 23ES in back I am fighting the distance Garmin wants between the Unit and the Transponder antenna 3 feet. To add tomy problem I have the Magnetometer in the tail and as I mentioned previously Garmin has concerns that my transponder antenna may be too close to the Magnetometer. I have it set up so I can switch the cables of the ADSB antenna and the Transponder antenna. The transponder is no big deal but my ADSB unit is up front and I already have it run. I was just a small amount short if I do the switch, so I was wondering if I was stretching the limits of the length of the ADSB in. In the End I will just hook it up and do the checks . Just trying to keep the crawling in back and re routing of wire to a minimum. The units are Transponder GTS 23ES, ADSB GRT39 R Thanks On Sat, Jun 11, 2016 at 3:23 PM, Robert L. Nuckolls, III < nuckolls.bob@aeroelectric.com> wrote: > At 08:20 AM 6/10/2016, you wrote: > > One other question if you cont mind.=C3=82 I am using RG400 for my ADSB and > with all this antenna location I may have to add about 6 " to the ADSB > cable.=C3=82 Its already about 12 feet long.=C3=82 This is just ADSB in so not > transmission.=C3=82 How much will I loose if I extend the cable with a > interconnect fitting ?=C3=82 I got into this long length because of the > transponder being in the back.=C3=82 > > > 6 inches? The losses added by 6" plus > connector to an existing 12' run cable > would be difficult to measure much less > observe in practice. > > A 12' length of RG400 will toss off about > 40% of your transmit/receive signals at > transponder frequencies . . . > > http://tinyurl.com/hdphfdv > > . . . again, probably not enough to be > observed in practice. But at Beech, we'd use > something more like LMR-400 for a loss of > about 15%. There are probably sellers > on eBay that would custom assemble a > cable for you. > > What model transponder are we talking about. > I like to read the wordage in the manual > associated with antenna locations. > > Bob . . . > ________________________________ Message 3 _____________________________________ Time: 04:35:13 PM PST US Subject: AeroElectric-List: Re: Antenna grounding From: "user9253" Another RV-8 builder posted: > I previously installed my transponder antenna under the RV 8 baggage floor on the left side. I mounted my Navworx ADSB antenna next to the innermost inspection cover on the right wing. This gave me the suggested 5 foot distance between the two and minimized cable length. Works like a charm. > Don http://www.vansairforce.com/community/showpost.php?p=788980&postcount=12 Manufacturer's lawyers probably specify the minimum distance between various aircraft antennas. And that distance is probably greater than necessary. Bob, how far apart should a 1090 MHz transmitting antenna be from a 978 MHz receiving antenna? And how far should a transponder antenna be from a com antenna? Thanks -------- Joe Gores Read this topic online here: http://forums.matronics.com/viewtopic.php?p=457041#457041 ------------------------------------------------------------------------------------- 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.