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GPS and XM Antenna Mounting Position?

jsharkey

jsharkey

Well Known Member
I was considering mounting the GPS and XM antennas on top of my RV6 Tip-Up glare shield just like the compass.

Anyone else done that? Wiring will be simpe.

I'm assuming that they can "see" through the plexi.

Any other ideas or comments?

Jim Sharkey
 
Other options

Bill Gill (N151WP - see first flight info on the main page) mounted the GPS antenna on a firewall bracket under his RV7 cowl. Don't know if others have tried this, but his GPS seems to get a nice strong signal through the fiberglass...

Regards,
Mike
 
GPA antenna location

I don't care for the idea of putting an antenna near the engine due to heat. Dan C has his GPS antenna FWF and had to replace it for an unknown cause. Wouldn't it be better on the glairshield under the windshield? An added benefit here is short and light antenna wire. Is there a down side to this location?

Bevan
RV7A wiring
 
Bevan said:
Is there a down side to this location?
Click to expand...

My prime antenna is under the cowl, but I have a backup GPS, 396 GPS, and XM antenna on my -8's glareshield. The downside? You see them reflected in the middle of your windshield much of the time.....

Paul
 
Ironflight said:
My prime antenna is under the cowl, but I have a backup GPS, 396 GPS, and XM antenna on my -8's glareshield. The downside? You see them reflected in the middle of your windshield much of the time.....

Paul
Click to expand...

Good info Paul - how good is the signal from the glare shield mount?
Jim Sharkey
 
gps Antenna location

Hi,

On my 7A my under cowl antenna location worked fine the first year but this past Arizona summer I has several temporary losses of signal to my Garmin 430 following an intermediate stop and the subsequent heat soaking after parking for 30 minutes or so. After departure and reaching cruise the antenna would resume operation. I'm going to switch to location on the top of the aft fuselage.

Don Bodnar
 
My XM and GPS antennea on mounted on the glare shield on either side of the roll support bar on my -9 slider. They are as far fwd as possible without touching the windscreen. Never a problem and almost out of sight.
 
bsacks05 said:
My XM and GPS antennea on mounted on the glare shield on either side of the roll support bar on my -9 slider. They are as far fwd as possible without touching the windscreen. Never a problem and almost out of sight.
Click to expand...

Do they have a good signal?
 
Not a problem for me

Jim,

I attached the antennas to the glareshield with small velcro patches. The wires pass down through a small hole in the glareshield which you wouldn't see unless you were looking for it. The 396 is in an Airgizmo panel mount.

I have logged 244 hours in the past 14 months. These hours were logged flying from the Atlanta area under lots of different conditions. I have traveled to south Florida, northern Maine, southwest Texas, and many places in between with no reception problems. If you are a purist who can't stand anything on the panel then find another place. This works and it's an easy installation. I like easy. An advantage to this I could even take the XM antenna out in a couple of minutes and take the unit and antenna with me. In some places without convenient internet access such as camping you can get weather while you are away from the plane.

Just my experience.

Larry Dickinson
N95LD
 
Jim,

My comments on your options...worth what you paid for it. ; )

1) Glareshield Mount - this is a great place from a reception/ease of wiring standpoint, but I would not recommend it. Installations I have seen with this mounting have a large glare that reflects off the canopy from the shiny antenna.

2) Under Cowl - I think this depends...are you planning to use a WAAS receiver (430W, etc.)? If so, I probably would NOT mount them there. There is significant RF shielding to the back of the antenna (big metal fuselage back there), and the WAAS reception is very sensitive to satellite mask angle. I know many people will post positive experience with their old NON-WAAS installations in that location (maybe it's OK), but I think people will have a higher likelihood of problems with the WAAS reception.

In the end, mine will likely go on top of the fuselage and I will pay the 0.15 knot penalty. ; )

Scott
7A Finishing
 
I first followed Dan C's example mouting the GPS antenna on a shelf on the firewall. Then, I found it interfering with my cowl hinge pin insertion. Later I borrowed another idea from Dan C and cut two access holes on my front top skin. These access panels are made of aluminum frame and fiberglass center. My GPS antenna is mounted under one of the panels. I was going to mount the WX antenna under the other. Due to the delay of GRT WX box, I did not get to do it before my first flight. Now I put the WX antenna at a corner under windshield. They both work well and never lossed signals.

Just as what Paul said that glareshield mount antennas cause reflection on the windshield. Not good for taking photos.

A word of caution, a few months ago several people warmed about the potential problem of access panel weakening the top skin. I only have less than 300 hours on my 9A and can not be sure about whether it is going to be okay for the long run.
 
Works fine on the glare shield

I have the XM antenna and a small TruTrak antenna velcroed to the glareshield on my RV-6 tip-up. Both receive solid signals (except when the GPS is corrupted "near" Holloman) and I've never noticed any glare issue. The only glare in my configuration would be so low that I'd have to be staring at the engine cowl to notice it, I think. As previously noted, this set-up allows easy removal when tied down on a questionable ramp or when I want the weather in the car.
 
passenger side

I have not noticed any glare from the antennas, but I mounted them on the passenger sider just in case.
 
On the tip-up canopy I install the antennae aft of the roll bar where the support brace joins the roll bar. One in each corner. They are out of the way there and have a clear view of the sky.
 
I never noticed any canopy reflection either from my glare shield mounted XM and GPS antennea. Just be sure, though, I ops check the set up today for about three hours down and back to the Little River fly in. Sky was crystal clear and lunch was superb. Also, this was my first time listening to Iron Maiden while flying! I felt like a teenager again!
 
I ended up attaching them behind the compass with Velcro tabs from Home Depot - 2 on the GPS and 4 on the XM - may have to use a crow bar to get them off! Wires pass through a single, split 1/4" ID by 1" OD grommet and then through the center lightening hole on the canopy brace. I'll feed the compass light wires through it too. I had to sand the ribs on the GPS connector by a few thou to get it to slip through the 3/4" grommet hole in the glare shield.

Pilot's eye view shows black GPS antenna blending into glare shield and the XM antenna largely hidden behind the compass. Looks good so far.

Thanks for all the input.
Jim Sharkey

xmgpsgx1.jpg
 
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