Mounting GPS antennas under panel cover

I'm thinking of mounting a couple of "mouse" GPS antennas on the inside of my fiberglass LS6 panel cover using Dual-Lock on the TOP of the GPS antenna.. Reason is to have more real estate to place the antennas, and still provide a "break-away" function if I have to jettison the canopy (and cover, which goes with it). Any opinions about any effect the plastic Dual-Lock would have on GPS reception?

My gut feeling is "no effect", but I claim no deep knowledge of the electromagnetic spectrum (other than how to run a no-lock intercept using an APQ-120...).

Comments?

Kirk
66

On Sunday, July 22, 2012 5:11:14 PM UTC-7, kirk.stant wrote:
I'm thinking of mounting a couple of "mouse" GPS antennas on the inside of my fiberglass LS6 panel cover using Dual-Lock on the TOP of the GPS antenna. Reason is to have more real estate to place the antennas, and still provide a "break-away" function if I have to jettison the canopy (and cover, which goes with it). Any opinions about any effect the plastic Dual-Lock would have on GPS reception?

My gut feeling is "no effect", but I claim no deep knowledge of the electromagnetic spectrum (other than how to run a no-lock intercept using an APQ-120...).

Comments?

Kirk
66

My concern is not RF absorbing (which will be minimal), but more the robustness of any adhesive tape on a too-hot-to touch black glareshield sitting on the ground on a 100F+ summer day. While 3M Dual-Lock is strong, and the adhesive on those strips typically much better/more stable at high temps, than any of the Velcro brand products I'd still be concerned about the adhesive "creeping"/"walking" or letting go on a really hot day. (but that is easy to test to see if its a problem)

My facorite under-panel mounts are actually made of thin, one layer fiberglass moulded around a foam replica of the antenna that are potted under the glareshield and then the foam core is removed. Where you pry open a springy entry flap and push in the GPS "puck". I've got one made like this under my ASH-26E panel for the XM weather receiver puck for my Gamin 496, so not exactly a GPS antenna but it works great in this mount (in this case there is no break-away, as the 496 goes away with the canopy, but the DC power to the 496 has a break-away connector. You could look at GPS options that break away at a connector.

Email me if you want and I'll try to find photos of the fiberglass mount for my XM antenna that Williams Soaring made.

Darryl

Originally Posted by kirk.stant

I'm thinking of mounting a couple of "mouse" GPS antennas on the inside of my fiberglass LS6 panel cover using Dual-Lock on the TOP of the GPS antenna.. Reason is to have more real estate to place the antennas, and still provide a "break-away" function if I have to jettison the canopy (and cover, which goes with it). Any opinions about any effect the plastic Dual-Lock would have on GPS reception?

My gut feeling is "no effect", but I claim no deep knowledge of the electromagnetic spectrum (other than how to run a no-lock intercept using an APQ-120...).

Comments?

Kirk
66

Hey Kirk,
I have a gps antenna mounted under the front glareshield of my shk. construction materials in the "skyview" of the antenna are some wood frames, fiberglass with flat matt spray paint, some 1/2 inch steel tubing for the canopy frame, and the plexi. I have had no issues with signal loss, I even shortened the original long antenna lead to about 14 inches by soldering. if you are concerned about hook and loop tape on the top of the antenna, you could make a thin metal tray which might also shield the antenna from other instrument emissions.
Good Luck, Good Lift!
Scott.

On 7/22/2012 7:13 PM, Darryl Ramm wrote:
On Sunday, July 22, 2012 5:11:14 PM UTC-7, kirk.stant wrote:
I'm thinking of mounting a couple of "mouse" GPS
antennas on the inside of my fiberglass LS6 panel cover using
Dual-Lock on the TOP of the GPS antenna. Reason is to have more
real estate to place the antennas, and still provide a
"break-away" function if I have to jettison the canopy
(and cover, which goes with it). Any opinions about any effect the
plastic Dual-Lock would have on GPS reception?

My gut feeling is "no effect", but I claim no deep
knowledge of the electromagnetic spectrum (other than how to run a
no-lock intercept using an APQ-120...).

Comments?

Kirk 66

My concern is not RF absorbing (which will be minimal), but more the
robustness of any adhesive tape on a too-hot-to touch black
glareshield sitting on the ground on a 100F+ summer day. While 3M
Dual-Lock is strong, and the adhesive on those strips typically much
better/more stable at high temps, than any of the Velcro brand
products I'd still be concerned about the adhesive
"creeping"/"walking" or letting go on a really hot day. (but that is
easy to test to see if its a problem)

My facorite under-panel mounts are actually made of thin, one layer
fiberglass moulded around a foam replica of the antenna that are
potted under the glareshield and then the foam core is removed. Where
you pry open a springy entry flap and push in the GPS "puck". I've
got one made like this under my ASH-26E panel for the XM weather
receiver puck for my Gamin 496, so not exactly a GPS antenna but it
works great in this mount (in this case there is no break-away, as
the 496 goes away with the canopy, but the DC power to the 496 has a
break-away connector. You could look at GPS options that break away
at a connector.

Email me if you want and I'll try to find photos of the fiberglass
mount for my XM antenna that Williams Soaring made.

I haven't seen Rex's solution, but maybe you can make a mount that
attaches to the instrument pod, holding the antenna up close to the
glare shield? That avoids the need for Dual-Lock or messing with
fiberglass. I used some 1/16" x1" x3" Lexan plastic to mount the
antenna, then bolted the end of the lexan to a convenient brace. The
flexible Lexan holds the antenna up to the inside of the glare shield.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)
- "Transponders in Sailplanes - Feb/2010" also ADS-B, PCAS, Flarm
http://tinyurl.com/yb3xywl
- "A Guide to Self-launching Sailplane Operation Mar/2004" Much of what
you need to know tinyurl.com/yfs7tnz

I have two little 'mouses' mounted under my panel cover. These have two screw holes on opposite sides for attaching. Thru these holes I would run plastic locking wire ties and around the top tubular panel frame ( S-H Discus ) suspending them in between the frame tubes. They (GPSs) are suspended a few inches apart just underneath the panel cover and have never failed to provide a signal. No glue or tape and easily to removed and replace when instrument work is required.
R

On Sunday, July 22, 2012 7:32:39 PM UTC-7, Eric Greenwell wrote:
On 7/22/2012 7:13 PM, Darryl Ramm wrote:
> On Sunday, July 22, 2012 5:11:14 PM UTC-7, kirk.stant wrote:
>> I'm thinking of mounting a couple of "mouse" GPS
>> antennas on the inside of my fiberglass LS6 panel cover using
>> Dual-Lock on the TOP of the GPS antenna. Reason is to have more
>> real estate to place the antennas, and still provide a
>> "break-away" function if I have to jettison the canopy
>> (and cover, which goes with it). Any opinions about any effect the
>> plastic Dual-Lock would have on GPS reception?
>>
>> My gut feeling is "no effect", but I claim no deep
>> knowledge of the electromagnetic spectrum (other than how to run a
>> no-lock intercept using an APQ-120...).
>>
>> Comments?
>>
>> Kirk 66
>
> My concern is not RF absorbing (which will be minimal), but more the
> robustness of any adhesive tape on a too-hot-to touch black
> glareshield sitting on the ground on a 100F+ summer day. While 3M
> Dual-Lock is strong, and the adhesive on those strips typically much
> better/more stable at high temps, than any of the Velcro brand
> products I'd still be concerned about the adhesive
> "creeping"/"walking" or letting go on a really hot day. (but that is
> easy to test to see if its a problem)
>
> My facorite under-panel mounts are actually made of thin, one layer
> fiberglass moulded around a foam replica of the antenna that are
> potted under the glareshield and then the foam core is removed. Where
> you pry open a springy entry flap and push in the GPS "puck". I've
> got one made like this under my ASH-26E panel for the XM weather
> receiver puck for my Gamin 496, so not exactly a GPS antenna but it
> works great in this mount (in this case there is no break-away, as
> the 496 goes away with the canopy, but the DC power to the 496 has a
> break-away connector. You could look at GPS options that break away
> at a connector.
>
> Email me if you want and I'll try to find photos of the fiberglass
> mount for my XM antenna that Williams Soaring made.

I haven't seen Rex's solution, but maybe you can make a mount that
attaches to the instrument pod, holding the antenna up close to the
glare shield? That avoids the need for Dual-Lock or messing with
fiberglass. I used some 1/16" x1" x3" Lexan plastic to mount the
antenna, then bolted the end of the lexan to a convenient brace. The
flexible Lexan holds the antenna up to the inside of the glare shield.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)
- "Transponders in Sailplanes - Feb/2010" also ADS-B, PCAS, Flarm
http://tinyurl.com/yb3xywl
- "A Guide to Self-launching Sailplane Operation Mar/2004" Much of what
you need to know tinyurl.com/yfs7tnz

I like that idea even more, easy to wire/check with the glareshield removed.

Darryl

Am 23.07.2012 02:11, kirk.stant wrote:
I'm thinking of mounting a couple of "mouse" GPS antennas on the inside of my fiberglass LS6 panel cover using Dual-Lock on the TOP of the GPS antenna. Reason is to have more real estate to place the antennas, and still provide a "break-away" function if I have to jettison the canopy (and cover, which goes with it). Any opinions about any effect the plastic Dual-Lock would have on GPS reception?

My gut feeling is "no effect", but I claim no deep knowledge of the electromagnetic spectrum (other than how to run a no-lock intercept using an APQ-120...).

Comments?

Kirk
66


Kirk,
I have used exactly that solution with two GPS mouses under my panel
cover (ASW24), no problem with the signal at all. Also the 3M Dual lock
tape has not come off in two consecutive years. A previous solution with
standard velcro tape failed because the tape glue didn't stand the heat.
--
Peter Scholz
ASW24 JE

My Volkslogger is mounted quite low under my Discus 2 panel. It's been there for six years and I have never had a connectivity problem.

Mike

I assume that if you have a DG with the very dull grey pod that the pod is carbon and that this won't work?

Brian

A couple of comments and medium-baked ideas;

1) The adhesive on 3M's Dual Lock is especially good, unlike most
velcro you find in stores. Dual Lock *should* stay stuck even in a
hot environment. You might troll the 3M site for temperature specs
(they mention aerospace).
2) I bolted my GPS antenna under the glare screen (which is not
mounted to the canopy). To allow for break away in your situation you
could use nylon bolts instead of metal bolts. To really make sure
they break away, you could remove some concentric material (cut a
groove) around the bolt near the head. Removing concentric material
is what is done for break away mounting of, for example, runway
lights.
3) Double stick tape? That should break away. But might have the
same temperature issues. Again, stick with 3M branded.

Good luck, John