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WAAS and Serious Satellite GPS Antenna Location

F

Frankster13

Active Member
What is the consensus on mounting GPS antennas? I am somewhat reluctant to mount these two antennas on the top of the fuselage aft of canopy but I don't want to mess around and mount internally on a ledge under back canopy only to get lousy reception.

Thoughts?
 
FWIW I just spoke to a very experienced avionics pro today and he said he is mounting GPS antennas on the dash visor with good effect
 
Quite a few of us (myself included) have built a small shelf under the FWF engine cowling and installed them there. The fiberglass cowling is transparent to the GPS radio signals as long as you don't use paint with metallic pigments.

I've got two Garmin and one Dynon GPS antennas up there with excellent reception.
 
I ran with a GX-60 GPS antenna and a 396 GPS and XM weather antennas on the glare shield of the RV-8A for years with no issue. I mounted a SkyView GPS receiver and GTN-650 antenna on the glare shield in the RV-10 and it worked. I note the Garmin GPS antennas are more sensitive to mounting than the SkyView, so your mileage may vary depending on what you are installing. For the new RV-8 project the SkyView GPS receiver is going on the glare shield but the GTN-650 antenna is mounted on the fuselage just aft of the rear seat, but still under the canopy.

Carl
 
My xm and gps antennas are on glare shield. The antennas need to be black or the reflection is a problem. Also, gps antennas located too close to each other will interfere with one another. John
 
jpowell13 said:
My xm and gps antennas are on glare shield. The antennas need to be black or the reflection is a problem.
Click to expand...

Similar to my setup except mine are under my glareshield with phonelic covered cutouts.

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My G430W antenna has been there since 2009 while my Dynon antenna has been there since 2013. I have never had a problem with either of them while both of them show full satellite reception.

:cool:
 
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Interference

In my case, it was my iLevil portable ADSB/GPS receiver that was interfering with the Garmin antenna for my 400W. It was interesting to watch the signal strength bars on the 400W drop as you moved the iLevil closer to the Garmin antenna. John
 
GPS puck location

I have my Dynon under the rear window and on a shelf mounted to the crossbar.

Many before me did this with no problems.
 
Black pucks on the glare shield...works beautifully. I use the "hook" velcro on the pucks which grabs the acrylic carpet on the glare shield like crazy.
 
Choose what's important to you: performance or looks.

If performance is the priority, than I suggest you follow the guidelines from the manufacturer as closely as possible (especially when it comes to WAAS/IFR navigator).

If looks is more important, than do whatever you want.
 
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airguy said:
Quite a few of us (myself included) have built a small shelf under the FWF engine cowling and installed them there. The fiberglass cowling is transparent to the GPS radio signals as long as you don't use paint with metallic pigments.

I've got two Garmin and one Dynon GPS antennas up there with excellent reception.
Click to expand...

+1 Good reception. They are mounted high, close to the cowl to minimize the aft shadow.

Edit: One day I will test the drag of a few fakes mounted behind the rear window to see if it is measurable. Even though mine are shelf mounted, Walt has good advice! It would leave more room under the cowl.
 
Antennas high on a firewall shelf? Installing cowl hinge pins can become a PITA with the shelf in the way. When fabricating, pay attention to how it all works together.

The OP asked about WAAS and Sirius XM proximity. These Garmin antennas (L to R, 696, XM, and ADS-B) are playing well together, although they are too close per the manuals. Location is under three layers of material, two fiberglass panels and the plexiglass canopy. Your mileage may vary.

GDL-82%20Component%20Placement.jpg
 
A win-win-win solution to this problem

I killed three birds with one stone to solve this problem. I have my tilt-up canopy set up for actual jettison-in-flight capability as I wear a parachute much of the time and do not want wire-connected devices that could interfere with the jettison process mounted to the glare shield. I also hate that when you open the tilt- up in heavy rain, a large amount of water dumps right onto the center stack of avionics, with the primary recipient being my GTN 750. One note, because my radio stack was moved about 5” to the left for a more pilot-centric panel, I did have to come up with canopy jetisson linkage that moves the actual pull handle to the right several inches, but it also increases the mechanical advantage of the pull and also provides a more secure slot, like an old knife-blade electrical switch, to hold the jetisson linkages securely closed. You can see the layout in the photo below. The jettison release is tucked behind the upper left corner of the iPad mount, which can easily be pulled out of the way for full access.

My solution for the GPS mount was to use .020 alclad to bridge from the upper panel top brace to the flange that the forward canopy closes against for the maximum possible width(about 19”), allowing for hinge clearance. This results in a water-deflector that routes intruding water to the sides where it drops harmlessly to the floor, and it also provides a perfect ground-plane for my G3X touch gps amtenna mounted rigidly dead center below the glare shield, which has a cooresponding cutout directly over the antenna location. With the canopy closed, the glare shield rests directly upon this added sheet of .020. Another advantage is that the upper panel is greatly stiffened by the added sheet, so it can withstand a considerable pull from either pilot or passenged using the upper edge of the panel to assist with ingress and egress. It is a win-win-win solution.

The gps antenna for my GTN750 is, of course, mounted externally on the turttledeck. This is all a work in progress that I will photo-document later.- Otis
2v2E7w7YWxBELK5.jpg
 
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$$$

If you are listening to Serious radio... you are paying too much.
I got a Sirius subscription for $6 a month.
So, I hope your sense of humour is intact.. fly low and take chances!
(glare shield in my RV)
 
NewbRVator said:
FWIW I just spoke to a very experienced avionics pro today and he said he is mounting GPS antennas on the dash visor with good effect
Click to expand...

My airplane has neither a "dash" nor a "visor". (Some pilots go crazy on "hanger" vs. "hangar". It is my mission in life to remove "dash" from the vocabulary of pilots everywhere!)

However, to answer the OP's question, I mounted all the GPS and XM antennas on top of the glair shield, above the instrument panel.

No issues with separation and away from the heat of the engine. Note, that there is a LOT of heat generated by being under the canopy on a hot sunny day! Enough to melt the GPS antenna for my Dynon PocketPanel and garage door opener. The other Dynon and Garmin antennas have not suffered the same fate.
 
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