Antenna help

A forum to discuss installation of avionics such as GPS, NAV & COMM radios, audio panels, auto pilots, etc.
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Joe Parish
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Antenna help

Post by Joe Parish »

Need help with what I need for antennas. I am building a day/night vfr but would like to eventually go IFR in this plane. I was thinking of going with Archer Vor/nav in one wingtip.

I was thinking a comm antenna on the belly. I would also need a transponder, ELT and GPS I was thinking of putting on top of the fuse behind canopy.

Do I need a marker beacon antenna for IFR or are they becoming extinct with GPS or would they still be useful? Do I need a glidescope antenna or would the VOR/Nav work for that?

Trying to educate my self on antennas currently any help is greatly appreciated.
Joe
N525XC reserved
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bruceh
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Post by bruceh »

I'm pondering the same questions and here is what I am going to do.
Dynon Skyview Transponder is down near the floor behind the baggage bulkhead. Antenna for that will be nearby on the centerline of the lower aft fuselage. The Dynon GPS antenna will be on the top of the fuselage behind the tipup canopy. The ELT antenna will also be on top of the aft fuselage, out in the breeze as recommended by the manufacturer.
I haven't decided on a comm yet, but the antenna for that will be under the pilot seat. I also want to add an APRS, so that will be under the copilot seat.
If I ever feel the need to go IFR, I will put the nav antenna in the wing tip (Archer type). I'll probably have a portable GPS, and that antenna can go up on the dash. A portable handheld comm would be my backup. Has anyone provided some sort of splitter to the comm antenna so that you could hook up the portable to the external antenna if needed?
Bruce Hill
RV-9A N5771H flying over 1100 hours!
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bullojm1
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Post by bullojm1 »

Hey Joe-

Here is what I did-

COMM Antenna's - I put two of the bent-whip COMANT antennas under the fuselage (I have a COM1 and COM2). You could always start with one off-center and provision to add a second antenna. I have heard mixed reviews of the Archer wingtip Comm antenna.

Transponder Antenna - I put it right behind the firewall, making sure it didn't interfere with the exhaust.

ELT - Under the empennage fairing.

NAV - I used an Archer antenna in the wingtip.

Marker Beacon - In the wingtip - I just stripped some coax and glassed it into the wingtip.

GPS Antenna's - I put both my antenna's under the cowling. As long as you don't use a metallic paint on your cowling, there won't be any interference.
Mike Bullock
http://www.rvplane.com
RV-7 | Superior IO-360 | Whirlwind 200RV
Garmin GTN650 | GRT Dual Sport SX EFIS
Status: FLYING!

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Joe Parish
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Location: Sioux Falls SD

Post by Joe Parish »

Mike

Did you use any old coax for the marker beacon or do I need the spendy RG-400? My understanding is a 38 to 40 inch piece of coax stripped and a connector put on the end for wing tip removal. Then a piece of coax run to back of the panel? I am a little confused on that because I came across a site where they just run a single wire back to the panel from the coax. Wondering which is right?
Joe
N525XC reserved
Empennage done
wings done
Fuse in progress
RV-9A

lgcdmb
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Post by lgcdmb »

I think you'll find that just about any conductive material will work. The marker beacon signal is very strong and at close range. Use any old coax you have sitting around.

To the original question, I'm using Archer style Nav antennas in the wingtips, and Delta Pop antennas for comm, UAT and transponder under the fuselage. Marker beacons are going away and it's legal to use an IFR certified GPS for fixes on an ILS approach (CAT I), so I've left off marker beacon capability.
David Barrett
RV-7 Wiring

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bullojm1
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Post by bullojm1 »

Joe Parish wrote:Mike

Did you use any old coax for the marker beacon or do I need the spendy RG-400? My understanding is a 38 to 40 inch piece of coax stripped and a connector put on the end for wing tip removal. Then a piece of coax run to back of the panel? I am a little confused on that because I came across a site where they just run a single wire back to the panel from the coax. Wondering which is right?
Joe-

I stripped rg400 coax for the marker antenna. Any conductor should work, and I don't necessarily think you need rg400 for the marker beacon antenna. I bought a lot of used rg400 off of ebay at a great price so using it for the marker beacon wasn't a cost issue.
Mike Bullock
http://www.rvplane.com
RV-7 | Superior IO-360 | Whirlwind 200RV
Garmin GTN650 | GRT Dual Sport SX EFIS
Status: FLYING!

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