VansAirForceForums  
Home > VansAirForceForums

-POSTING RULES
-Advertise in here!
- Today's Posts | Insert Pics

Keep VAF Going
Donate methods

Point your
camera app here
to donate fast.

  #1  
Old 12-27-2012, 08:41 AM
Kahuna's Avatar
Kahuna Kahuna is offline
 
Join Date: Dec 2004
Location: Gold Hill, NC25
Posts: 2,419
Default 796 Pirep & GDL 39

Recently made some panel changes to get the 796 on it. I primarily went for this unit due to its feature set and ADSB weather integration with the GDL 39 which I also wanted to move to off XM.
The bare wire install with the docking station is a nice installation for the RV-8. I do not like things running around my cockpit like ipads and things. I preferr clean and usable.

I mounted the unit with screen tilt up and inward toward me more direct field of view. This is useful and makes touch screen activity easy.
I found this my first touch screen in the cockpit to be actually very nice. The speed at which you can move, select, pinch, expand, scoll etc on the unit is faster than I can mentally keep up. ADSB weather comes available at ~2k'agl.
I thought the GPS signal quality running around the hanger and house with it was going to be fine and not need an external antenna. I was wrong. In the weather at night I have twice lost gps signal while airborne. I have the remote antenna for the 796 on order. Ill add that to my low profile antenna farm on me glare shield.
I remote mounted the GDL 39 and remote mounted the external ADSB antenna to the belly of the plane. Again I dont like things running around the cockpit. Boxes in view, antennas sticking up etc. It fit nicely between the right gear tower and the baggage wall. A 90deg SMA connector on the RG400 kept a low profile install. Neat, clean, and out of the way.
I have tried both hard wire and bluetooth on the GDL 39. I found bluetooth less reliable with the GDL unit mounted a couple of metal plates away from the 796. So I recommend hard wire for remote installs between the GDL 39 and the 796.

I have had 2 issues so far with the 796.
1. Audio noise as discussed in this thread.
2. 'Inside class B airspace warnings' when Im not. I have found that it says im 'inside' when Im within 1k' above or below. I can find no settings for this. SUA alarms are either on or off. The 'airspace ahead' alarms seem pretty accurate. But for me living under a Class B coming under, in and above it, this alarm has made me act when I need not. Alarm comes on "inside class B xxx' and I act and then get frustrated. The moving map data on the altitudes of the B are fine. I think its a bug. Could be operator error. Trying to navigate the Garmin forums has been less than useful. Im running the current software.
Also, in the moving map depiction of class B, with the high res screen it would be nice if the B veils had altitude indications. So I know what they are and if Im headed towards the need to do something.

I have not been able to get any waypoint data 'in' items to work yet. Im trying to get flight plan or waypoint data from other units to send it to the 796 but the fix for this eludes me now. Im still poking away at it.

All in all I very much like the unit. It would be nice if it were tablet size. It is a big and bulky beast. But it is feature rich, provides for panel integration with weather, and has a handsome screen thats easy to use.

End of report.
__________________
Kahuna
6A, S8 ,
Gold Hill, NC25

Last edited by Kahuna : 12-27-2012 at 09:12 AM.
Reply With Quote
  #2  
Old 12-27-2012, 09:05 AM
g3xpert's Avatar
g3xpert g3xpert is offline
 
Join Date: Sep 2010
Location: Olathe, KS
Posts: 3,093
Default

Quote:
Originally Posted by Kahuna View Post
I thought the GPS signal quality running around the hanger and house with it was going to be fine and not need an external antenna. I was wrong. In the weather at night I have twice lost gps signal while airborne. I have the remote antenna for the 796 on order.
[...]
'Inside class B airspace warnings' when Im not. I have found that it says im 'inside' when Im within 1k' above or below. I can find no settings for this. SUA alarms are either on or off. The 'airspace ahead' alarms seem pretty accurate. But for me living under a Class B coming under, in and above it, this alarm has made me act when I need not. Alarm comes on "inside class B xxx' and I act and then get frustrated. The moving map data on the altitudes of the B are fine.
[...]
I have not been able to get any waypoint data 'in' items to work yet. Im trying to get flight plan or waypoint data from other units to send it to the 796 but the fix for this eludes me now. Im still poking away at it.
Hello Mike, glad to hear you are having success with your 796 and GDL 39. I think you provided the answer to your own first question above - remember that accurate GPS altitude measurement relies on having a reliable signal and a good antenna view of the sky. Typically a marginal installation with poor GPS reception will cause the same sort of airspace and/or terrain warning issues you describe. I suspect your problem will clear itself up once you install a remote antenna and give the unit an opportunity to receive a good signal.

As a side note, once you have your GPS reception issue cleared up, I think you might find our "Smart Airspace" feature (documented on page 63 of the aera 79x Pilot's Guide) to be useful, given your proximity to Class B airspace.

Make sure you have verified the RS-232 wiring between your GNS 430 and your aera 796 (TX on the 430 goes to RX on the aera) and configured the correct serial ports to "Aviation" on the 430 and "Aviation In" on the aera. If you are still having problems, drop us an email with your installation details using the link below and we will try to help.

- Matt
__________________
Garmin G3X Support
g3xpert@garmin.com
1-866-854-8433 - 7 to 7 Central Time M to F
Please email us for support instead of using Private Messaging due to the limitations of the latter.
Reply With Quote
  #3  
Old 12-27-2012, 09:09 AM
RV8iator's Avatar
RV8iator RV8iator is offline
 
Join Date: Nov 2006
Location: Saint Simons Island , GA
Posts: 1,635
Default

I get "inside SUA" or "inside Class B" warnings on my 496 and my GNC300XL when I'm physically not in them but close. Everytime I check to see exactly what's going on it's the GPS altitude that's different from the barometric altitude that's triggering the warnings. Haven't figured a way to stop that from happening.
__________________
Jerry "Widget" Morris
RV 8, N8JL, 3,100+ hours on my 8.

VAF #818
Saint Simons Island, GA. KSSI
PIF 2007 - 2022

I just wish I could afford to live the way I do
Reply With Quote
  #4  
Old 12-27-2012, 09:18 AM
Walt's Avatar
Walt Walt is offline
 
Join Date: Aug 2005
Location: Dallas/Ft Worth, TX
Posts: 6,340
Default

On the 696 there is an "altitude buffer" setting under the alarms menu, I keep this set pretty low (200' if I recall) to eliminate these eroneous alarms.
__________________
Walt Aronow, DFW, TX (52F)

EXP Aircraft Services LLC
Specializing in RV Condition Inspections, Maintenance, Avionics Upgrades
Dynamic Prop Balancing, Pitot-Static Altmeter/Transponder Certification
FAA Certified Repair Station, AP/IA/FCC GROL, EAA Technical Counselor
Authorized Garmin G3X Dealer/Installer
RV7A built 2004, 2000+ hrs, New Titan IO-370, Bendix Mags
Website: ExpAircraft.com, Email: walt@expaircraft.com, Cell: 972-746-5154
Reply With Quote
  #5  
Old 12-27-2012, 09:27 AM
g3xpert's Avatar
g3xpert g3xpert is offline
 
Join Date: Sep 2010
Location: Olathe, KS
Posts: 3,093
Default

Quote:
Originally Posted by RV8iator View Post
I get "inside SUA" or "inside Class B" warnings on my 496 and my GNC300XL when I'm physically not in them but close. Everytime I check to see exactly what's going on it's the GPS altitude that's different from the barometric altitude that's triggering the warnings.
Yes, due to the nature of altimetry, GPS altitude and barometric altitude will seldom agree when the aircraft is not on the ground. Since a portable GPS unit does not have a way to measure barometric altitude, it must use GPS altitude for airspace detection, with the addition of a small "buffer" of a few hundred feet to help account for the difference between GPS altitude and barometric altitude. Of course, the aircraft's altimeter and the pilot's judgement should be used to make the ultimate determination about airspace (and the alerts can also be disabled by the user if desired).

I will point out that the above statement only applies to portable GPS units and is not the case with our panel-mount cockpit displays such as the G3X system, which uses its own highly accurate pressure sensor to determine the aircraft's barometric altitude.

- Matt
__________________
Garmin G3X Support
g3xpert@garmin.com
1-866-854-8433 - 7 to 7 Central Time M to F
Please email us for support instead of using Private Messaging due to the limitations of the latter.
Reply With Quote
  #6  
Old 12-29-2012, 05:59 AM
Tooch Tooch is offline
 
Join Date: Nov 2011
Location: Amelia, Va
Posts: 314
Default gps antenna needed?

I was wondering if you needed to buy another antenna for the 796. I thought the GDL 39 had a gps reciever in it also so by connecting it to your 796, it should take over as your gps reciever.
Reply With Quote
  #7  
Old 12-29-2012, 06:09 AM
Brantel's Avatar
Brantel Brantel is offline
 
Join Date: Mar 2006
Location: Newport, TN
Posts: 7,513
Default

Quote:
Originally Posted by Tooch View Post
I was wondering if you needed to buy another antenna for the 796. I thought the GDL 39 had a gps reciever in it also so by connecting it to your 796, it should take over as your gps reciever.
You still need both.

One does not take over GPS duties for the other....
__________________
Brantel (Brian Chesteen),
Check out my RV-10 builder's BLOG
RV-10, #41942, N?????, Project Sold
---------------------------------------------------------------------
RV-7/TU, #72823, N159SB
Lyc. O-360 carbed, HARTZELL BA CS Prop, Dual P-MAGs, Dual Garmin G3X Touch
Track N159SB (KK4LIF)
Like EAA Chapter 1494 on Facebook
Reply With Quote
  #8  
Old 12-29-2012, 08:22 AM
g3xpert's Avatar
g3xpert g3xpert is offline
 
Join Date: Sep 2010
Location: Olathe, KS
Posts: 3,093
Default

Quote:
Originally Posted by Tooch View Post
I was wondering if you needed to buy another antenna for the 796. I thought the GDL 39 had a gps reciever in it also so by connecting it to your 796, it should take over as your gps reciever.
Hello,

Take a look at this thread and it should help explain.

- Matt
__________________
Garmin G3X Support
g3xpert@garmin.com
1-866-854-8433 - 7 to 7 Central Time M to F
Please email us for support instead of using Private Messaging due to the limitations of the latter.
Reply With Quote
  #9  
Old 12-29-2012, 02:28 PM
floridawing floridawing is offline
 
Join Date: Jan 2010
Location: Orlando, Florida
Posts: 141
Default 796 dock

Hello, nice installation! are you using the Garmin docking station or a aftermarket? Thanks!
Reply With Quote
  #10  
Old 12-29-2012, 03:41 PM
Kahuna's Avatar
Kahuna Kahuna is offline
 
Join Date: Dec 2004
Location: Gold Hill, NC25
Posts: 2,419
Default

Yes the Garmin docking station.
There is a U channel with bends to allow the dock to have some tilt up and in I made on a brake.
The docking station is great, but now that I have the external antenna, you cant just dock and undock, you have to remember to pull the antenna wire in/out.
__________________
Kahuna
6A, S8 ,
Gold Hill, NC25
Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -6. The time now is 03:26 PM.


The VAFForums come to you courtesy Delta Romeo, LLC. By viewing and participating in them you agree to build your plane using standardized methods and practices and to fly it safely and in accordance with the laws governing the country you are located in.