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Old 11-08-2018, 08:00 PM
63robskin 63robskin is offline
Join Date: Jan 2018
Location: Magnolia, TX
Posts: 14
Default GPS/Coax connector extension

The cabin top on the 10 is rather thick. When I mount the GPS antenna, will I need special or longer than normal coax connectors? If where can I get them?

Last edited by 63robskin : 11-08-2018 at 08:07 PM.
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Old 11-08-2018, 08:40 PM
DRMA DRMA is offline
Join Date: Jan 2016
Location: Sugar Land, TX
Posts: 373

Note that when I asked, Van's does NOT recommend mounting any antennas on the fiberglass cabin for structural reasons. So I have mounted my antennas on the aluminum skin behind the fiberglass cabin top.

I have mounted 2 GPS antennas, 1 Comm antenna, and the ELT antenna in the space aft of the fiberglass cabin top while meeting the recommended spacing between antennas. I then have a second Comm antenna mounted on the belly aft of the baggage bulkhead, the VOR/ILS whiskers at the top of the vertical stabilizer, and Xpndr antenna mounted under the front seats near the tunnel.

Of course, as an experimental aircraft, you can mount the antennas on the fiberglass top if you wish, even if Van's doesn't recommend it.
Dave Macdonald

RV-10 First Flight April 1, 2020. Currently in Phase 1
2020 VAF Dues Paid
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Old 11-08-2018, 08:46 PM
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wjb wjb is offline
Join Date: Nov 2012
Location: Half Moon Bay, CA
Posts: 971

Patch antennas, such as GPS antennas, benefit greatly from being on a ground plane, like the top of the tail cone. It has the benefit also of being 25 to 32 mils thick, and in no need of a fancy connector. I've never seen an easy to get extended connector (BNC or TNC, depending on your antenna)
Bill Bencze
N430WB RV-7 #74152, tip-up; IO-360; CS. Pushing toward first flight in 2020!

Log at:
Defeating gravity one rivet at a time
VAF 2020 donation happily made
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Old 11-08-2018, 10:58 PM
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awmuhs awmuhs is offline
Join Date: Jun 2013
Location: Tucson, Az
Posts: 141
Default Gps Antennas

I mounted my garmin and dynon GPS antennas side by side on the cabin top about 6 inches forward of the seam with tail cone.

Didnít think to ask if it was a bad idea.

Found out after it as done that it was not reccomended and that they were to close together besides.

4 1/2 years later everything works fine and I did not need any special connectors because of the fiber glass thickness.
Alan Muhs
Tucson, Arizona
Dues overpaid December 17, 2018
RV12iS Southern Arizona Teen Aviation: #1 airplane flying, #2 airplane working on finish kit, #3 airplane working on tail kit.
RV10 flying since July 2014- 650hrs as of Dec 2019
RV6A sold after 500 hours of flying
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Old 11-09-2018, 07:51 AM
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9GT 9GT is offline
Join Date: Jan 2010
Location: Southern Michigan
Posts: 1,858

I mounted my GTN-650 GPS antenna on the cabin cover when I built my RV-10. I put it just aft of the joggle in the thin section of the cabin cover. I installed a foil ground plane for the antenna on the inside of the CC that was eventually finished over with my headliner. My center roof console covered the antenna 90* TNC connection. It worked great. You just have to plan ahead for antenna ground plane requirements when working with composite structures. There are many ways to work in the antenna GP requirements.
David C.
Howell, MI
RV-10: #41686 Under Construction
RV-9A: #90949 Under Construction
RV-10: #40637 Completed/Sold 2016
Cozy MKIV:#656 Completed/Sold 2007
"Donor Exempt" but donated through Dec. 2020
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Old 11-09-2018, 08:26 AM
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flion flion is offline
Join Date: Dec 2007
Location: Flagstaff, AZ
Posts: 2,554

I placed my two GPS antennae near the centerline, one between the doors and the other about halfway back, to maintain the spacing recommended by Garmin. I routed out the opening for the antenna connection and a 90 degree exit for the cables, then glassed the raw foam between the layers of glass. I won't know until it's flying if there's a problem but I'll keep an eye on it.

However, someone had a potentially good idea of putting their antennae in the space between an overhead console cover and the cabin top. The GPS in my -6A has been under the fiberglass wingtip without problems for the past 10 years and I think that the extra thickness of the foam and fiberglass in the cabin top should not prove to be a problem. I didn't run into any carbon fiber where I mounted my antennae, so I think the top centerline should be clear of obstruction to GPS signals. Just a guess, though, I don't have any practical testing to back it up.
Patrick Kelley - Flagstaff, AZ
RV-6A N156PK - Flying too much to paint
RV-10 14MX(reserved) - Fuselage on gear
EAA Technical Counselor #5357
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Old 11-09-2018, 09:11 AM
rv7charlie rv7charlie is offline
Join Date: May 2006
Location: Pocahontas MS
Posts: 3,882

Just a heads-up on ground planes. All the sources I've found indicate that patch antennas (what we typically see for GPS) contain their own ground plane.
One link:

These are not 1/4 wave whips.
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Old 11-09-2018, 09:13 AM
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az_gila az_gila is offline
Join Date: Jan 2005
Location: 57AZ - NW Tucson area
Posts: 9,970

Originally Posted by rv7charlie View Post
Just a heads-up on ground planes. All the sources I've found indicate that patch antennas (what we typically see for GPS) contain their own ground plane.
One link:

These are not 1/4 wave whips.
Yes, but the GTN manuals require a GPS antenna ground plane...
Gil Alexander
EAA Technical Counselor, Airframe Mechanic
Half completed RV-10 QB purchased
RV-6A N61GX - finally flying
Grumman Tiger N12GA - flying
La Cholla Airpark (57AZ) Tucson AZ
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