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GPS antenna location

N661DJ

Well Known Member
I am installing the Dynon Skyview GPS in my 8A and was wondering where
to place the GPS antenna. I have seen GPS antennas placed under the top fiberglass cowling?? this would be ideal, but was concerned as to the performance.
Other suggestions???
Dick
 
I have both my gps antennas Dynon and Garman under the cowl and have no issues with reception or heat.

Also it's a real easy install, no reflections in the canopy screen.

Cheers
 
Works great

I have the Dynon GPS puck under the cowl in an RV4 and inside the fuselage on a Glasair and both work well. You should have no problems.
 
Mounted to motor mount

I have my Garmin 430W and Dynon Skyview GPS antennas mounted to a bracket on the engine mount. As long as I am doing aerobatics they work just fine. Not sure if this location would work with the new Dynon 2020 GPS which apparently needs better signal strength for the required integrity.

Where have folks mounted GPS antennas on an 8 externally?

Cheers

Nigel
 
Nigel,
If the 430W works in your location, we expect the GPS-2020 will as well. Our concern is that the GPS-250 was much more sensitive than the 430W so it could be in a place that a complaint GPS wouldn't work.

I hate to undermine a sale, but I do have to ask- if you have a 430W, why go with the GPS-2020? We can get you ADS-B compliant with a single wire between the 430W and the Dynon transponder.
 
I mounted mine externally between the aft end of the top cowl and the windscreen. Works fine and eliminates any chance of airframe shadowing. Perhaps not as aesthetically pleasing but it works for me.
 
One thing I found out the hard way is that GPS antennae need to be separated by 12 inches or more. Otherwise you can get something called harmonic resonance which degrades reception. John
 
RV8A GPS Antennas

I am in the process of upgrading my panel and in discussions with Garmin, the install manual, and the person who helping me install it is very knowledgeable about electrons and the regulations we are installing it on the turtle deck under the canopy. I know it would look better under the cowling for sure but the IFR regs are clear, if you are going to operate IFR and the Garmin folks have had cases where you still have GPS but you do not have full WAAS capability, plus heat is an enemy of the antenna - may take a lot of time but is a risk according to the specs, not something you want to risk if you really need it or plan to use it in my opinion. I placed my back up GPS for the G3X on the glare shield on one side and placed my D2 back up on the other side to keep them as many inches away from each other as possible. Hope this is helpful to you.
 
Super paint job and photo Carl. A neat out of the way location for the antenna, in hindsight I think it would have been better to do the same.

My G430W and Dynon GPS 250 antennas are mounted on the same plate right next to each other and the only drop outs I have experienced are when I am upside down or when there has been NOTAMed GPS jamming testing going on at China Lake.

Cheers
Nigel
 
Two spots

We put the EFIS GPS antenna on the front baggage upper skin about three inches to the left of the hinge line and about halfway or a little forward of halfway between the wind screen and the fire wall. This keeps it out of the engine compartment, its heat, and its vibration. Your eye dose not see it when you are flying and the drag is no thing if you use a teardrop antenna. We have a Garmin 460 touch EFIS in the panel, so you just cut a small hole in the bulked at the rear of the front baggage and send the wire from the back of the EFIS out to a 90* at the bottom of the antenna. With the stiffener that go's along the hinge line you can just use plastic ties to the stiffener to hold the wire run. We also have a Garmin ADS-B and a place for The WAAS box just behind the rear baggage so the WAAS GPS antenna go's on the rear turtle deck just like you see Carl N. has his in the picture above. The ADS-B box in the Garmin system has a third GPS plug on it but the other two will override it so we did not use it as a back-up The WAAS will be recognized as the primary and if it go's down the system will switch to using the EFIS GPS as the default.
Hope this helps, Yours, R.E.A. III #80888
 
gps ant.

If you google 'rv14 panel' the fifth pic shows what looks like a Dynon gps antenna painted black on the glare shield. I had heard that painting these antennas was detrimental, or is there some types of paint which should/should not be used?
 
When the -8 came to me all GPS antennae were on a shelf on the firewall under the cowl. Seemed to work fine but the installation significantly complicated cowl removal. I moved everything to the glareshield since the flat wrap windscreen freed up the real estate. The turtledeck was my fallback.
 
As a follow up, the GTN 650 manual specifies a fairly significant minimum length of coax between the reciever and the antenna (with no coiling allowed). This drives the antenna well aft of the instrument panel area... Does the Dynon have this restriction?
 
Which install manual are you looking at, this is from the 650 TSO manual:

"If RG-142B or RG-400 is used, 1.5 dB equates to a length of approximately 6.5 feet of
cable with a connector on each end. RG-142B or RG-400 cable can be used as long as the
length is less than 35 feet. For longer lengths, use low-loss double or triple shielded 50
coax."

"For very short runs, where the loss is less than 1.5 dB, additional cable should be used to increase
the loss to within 1.5 dB to 6.5 dB. This additional cable may be coiled, taking into account the minimum bend
radius of the cable."
 
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I mounted mine externally between the aft end of the top cowl and the windscreen. Works fine and eliminates any chance of airframe shadowing. Perhaps not as aesthetically pleasing but it works for me.

This is what I'm doing because I may be overly concerned with the Texas heat.
 
Thanks for that Walt. The "no coiling" was a very specific admonition from my avionics guy, now that I think about it.
 
antenna coiling

Thanks for that Walt. The "no coiling" was a very specific admonition from my avionics guy, now that I think about it.

If the antenna is coax, coiling should make no difference as long as it is not to tight to damage. If you are using super hi tech "gore" coax, then refer to manu. For non coax antennas, they should not be coiled because this will add an impedance and cause a mismatch. So coax, ok to coil; non coax, do not coil.
 
gps installation

I installed the 430W and the regular Dynon GPS inside the wing tip and have excellent reception.
 
If you google 'rv14 panel' the fifth pic shows what looks like a Dynon gps antenna painted black on the glare shield. I had heard that painting these antennas was detrimental, or is there some types of paint which should/should not be used?

For my RV-8A and RV-10 the GTN-650 and Dynon GPS antenna went on top of the glare shield, wrapped with a piece of dark gray cloth to eliminate the glare.

Both have worked flawlessly in this location.

Carl
 
Just a quick FYI.

I recently did the SV-GPS-2020 upgrade from Dynon. I had my GPS-250 on a small shelf under the cowl. I figured I would start there and try it first with the new one. Everything seems to be working fine with the 2020 in that location so far.
 
Thanks for that Walt. The "no coiling" was a very specific admonition from my avionics guy, now that I think about it.

GPS20A also has this minimum coax length, and also allows the cable to be coiled. The GPS antenna is installed dorsally on the rear fuselage just abaft of the canopy (canopy slides over it when opened.) The GPS20A is mounted to the rear baggage compartment upper wall. There is a backup GPS antenna for the G3X mounted on the glare shield. The second G3X display and the GDL39R GPS receivers are not connected to antennas.
 
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what we did.

We just put it on top of the front baggage skin, about half way in the middle of the door length and maybe an inch or more behind the door hinge. Your eye will not see it there while in flight, there is very little drag at that location, it is out in the open for best reception and it is not in the engine compartment in the way, heat or oil.
Just what we did and clad we did. Yours, R.E.A. III #80888
 
Easy...peasy

I slapped mine on the glare shield, sprayed it with a coat of flat black, and can honestly say I never notice it. Was super easy to install. One less thing to work around during your oil filter change.
 
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