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GPS Position Issue: Garmin G3X With GPS-20A

Hello

I have installed a Garmin suite in my Vans RV7 build and I am still working through testing and commissioning the system. I am located in New Zealand.

However I am having an issue where I have been unable to get a GPS position lock / date & time update in the G3X system. After countless attempts I have been advised that this can take between 1 - 3 hours for the system to determine it is located in NZ and not the US for the first time.

Last weekend I put the RV7 out the front of my house with a clear view to the sky for about 4 hours while connected to my DC power supply. After this time the system still didn't have a GPS position lock. The info screen was filled with satellites and at one point there were 3 green (although only 2 were when I took the attached photo). At the end of 4 hours I also placed my hand over the GA-35 antenna and quickly the satellites dropped off the G3X display, so the antenna appears to be working correctly?

I have been emailing the [email protected] support team since March about this issue but I get large delays between email replies and have had very little feedback on the problem from them in the past 3 months other than a copy of the GA-35 antenna installation manual and the comments: I see no reason why the GPS 20A would not operate in New Zealand. We advertise the GPS 20A as a "global solution".

As I am concerned about the large investment I have made and running out of warranty cover / support before getting a resolution to my issue (which could well be a problem with my installation) I thought I would ask here if anyone has any thoughts, suggestions, ideas, or things that I could try?

https://ibb.co/gZBYXsZ

gZBYXsZ


Thanks,
Jonathan
 
I have two thoughts. First you say last weekend but in your picture the gps date says May 30. Is there a way to adjust the date? Second, the G3X has an internal gps. Have you thought of getting a second antenna and try that GPS?

Jay
 
I have two thoughts. First you say last weekend but in your picture the gps date says May 30. Is there a way to adjust the date? Second, the G3X has an internal gps. Have you thought of getting a second antenna and try that GPS?

Jay

Thanks for the reply.

Correct it has the wrong date and time, but I assumed this info is related to the current GPS details and when it actually locks on it will receive the correct date and time information via GPS? Maybe not though, I could see if it is adjustable within the G3X.

No I haven't tried the built in G3X GPS as I don't want to spend another few hundred dollars on another GPS antenna for testing as the internal unit is no good for supplying GPS ADSB position information into my GTX-45R transponder etc so this isn't a viable option for my long term solution. I guess I could try that as a test though for my current antenna, although will require a new cable as the installed one won't reach the G3X.

Jonathan
 
You can get a GA 26C or GA 56 on eBay starting at $19USD each, some with free shipping. It's really not a bad idea to install the secondary antenna on the GDU for backup. It is suggested by Garmin. I have a GPS 20A with my G3X but also have a GA 26C on the glareshield connected directly to the GDU. If anything were to happen to the CAN Bus or RS232 channels the GDU will keep on trucking with the GA 26C. If you prefer to hide the antenna under the cowl or have it external then the GA 56 teardrow profile antenna would be the other choice.
 
Problem

Jonathan
The first thing I would try is borrow another antenna and coax and try that, if you get similar results then it is back to the unit, and garmin.

Good luck
Rob
 
I see by the times displayed that the box still thinks it is in Kansas (Garmin home) and/or doesn’t know about daylight savings time. How old is the software? There was a ‘gps rollover’ (the memory of weeks got full, and rolled over to zero.) in 2019. Newest software should have dealt with that, if it was an issue.
Contact Garmin on this forum again. He is customer oriented, and if you register a problem now I imagine he’ll not let your warrantee expire until it’s fixed.
 
Last edited:
Hi All, Garmin have finally got back in touch with me to say that there is a known issue with the GPS-20A acquiring a GPS signal in Oceania and needs to be left on overnight to acquire a signal the first time. Apparently there will be a fix coming in a new software release at some stage to resolve this behavior and make this happen within 15 minutes ... just not sure when this update is due.

Attaching a secondary 26C antenna for the GDU460 (while a good idea) and manually setting the date and time will not correct the issue as its directly related to the firmware / hardware within the GPS-20A.

Thanks All, guess I play the waiting game now.
 
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