Long time to get GPS signal
Printed From: Avidyne
Category: Avidyne General
Forum Name: IFD 5 Series & IFD 4 Series Touch Screen GPS/NAV/COM
Forum Description: Topics on Avidyne's IFD 5 Series and IFD 4 Series Touch Screen GPS/NAV/COM
URL: http://forums.avidyne.com/forum_posts.asp?TID=1268
Printed Date: 05 May 2024 at 5:59am
Software Version: Web Wiz Forums 12.01 - http://www.webwizforums.com
Topic: Long time to get GPS signal
Posted By: bcool
Subject: Long time to get GPS signal
Date Posted: 01 Apr 2017 at 12:06pm
| The last two times I've gone flying it's taken about 3 minutes from startup to acquire a GPS signal on my IFD540. This is a LOT longer than it used to take - does this mean I might have a problem somewhere? |
Replies:
Posted By: LANCE
Date Posted: 01 Apr 2017 at 1:48pm
| Are you running 10.2? |
Posted By: comancheguy
Date Posted: 01 Apr 2017 at 1:52pm
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I have seen this as well. All of my other GPS's (Dual, 496) have a sgnal, but the 540s show yellow. They usually don't go green until takeoff. This is fine, VFR, but it worries me on an IFR departure. With only a GPS approach back in. I noticed it after the 10.2 upgrade, also. No change from 10.1.1.0. Anyone know what is up with this? Ken
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Posted By: bcool
Date Posted: 01 Apr 2017 at 3:06pm
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FWIW, I haven't upgraded to 10.2 yet. I searched the web since I posted this and have found several instances of the Garmin antennas going bad, so I wonder if that might be what's happening? |
Posted By: George P
Date Posted: 01 Apr 2017 at 5:44pm
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I just installed a new IFD540 (S/W ver. 10.2) today, using the existing Garmin antenna. It seemed to take a bit longer to acquire the GPS system than the Garmin generally did, but I attributed it to the fact that it was acquiring from a new location. I will time it tomorrow. Incidentally, the installation went great and the setup was relatively easy. My only issue seems to be my GDL69 weather interface. It seems I have an earlier version of the GLD69 software that the IFD does not interface with. George
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Posted By: AzAv8r
Date Posted: 01 Apr 2017 at 6:02pm
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My IFD540 has taken what I perceived as a long time to acquire only three times. The very first time when we installed it, the very first time we powered it on out of the hangar after returning it for the hardware update service bulletin that was needed for the first units, and the very first time after installing 10.2. On a normal power up, with a decent sense of the time, an accurate location, and recent ephemerides stored for the GPS constellation, it acquires reasonably quickly. Change any of those, I would expect it to take longer. If I haven't flown for a while, it seems to take a little longer, but not as long as those three times. But I didn't time any of the acquisitions. Maybe someone who has not yet done the 10.2 update can time their last acquisition before the update, and the first acquisition after the update. |
Posted By: comancheguy
Date Posted: 01 Apr 2017 at 6:03pm
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I have one Garmin antenna from my 530W, and my second is new Avidyne antenna. So, that doesn't seem like it. It doesn't seem to go from GPS to GPS until I take off. I'll have to watch next time and see EXACTLY when it go green. Maybe this is working as designed. I may have to RTFM... Ken
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Posted By: dmtidler
Date Posted: 01 Apr 2017 at 7:04pm
| Just to clarify...did you have an active flight plan in the FMS prior to T/O? Without an active flight plan prior to T/O, I believe this normal IFD behavior. |
Posted By: teeth6
Date Posted: 01 Apr 2017 at 7:19pm
| I believe this is normal. When I enter a flight plan, the GPS stays yellow until I takeoff or activate the plan. Once I do either of those, it goes green. |
Posted By: mfb
Date Posted: 01 Apr 2017 at 7:59pm
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Press the Activate line select key as soon as you finish entering the flight plan. Then the GPS indicator will be green from the start. (Unless there's no GPS reception.) Mike |
Posted By: comancheguy
Date Posted: 01 Apr 2017 at 8:09pm
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Interesting! I'll experiment. I'm flying in the morning. Ken
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Posted By: mfb
Date Posted: 01 Apr 2017 at 9:13pm
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And another thing.... If you want to find out what the GPS receiver is really doing, go to the AUX-SYS page and press the Select line select key until it shows Select GPS. That will bring up the GPS status page. I got fooled on one of my early flights with the IFD540. I didn't activate the flight plan, so the GPS caption stayed yellow. I was convinced that the GPS failed until I took off and it magically fixed itself by activating sutomatically. Now it's on my pre-takeoff checklist. Mike |
Posted By: comancheguy
Date Posted: 01 Apr 2017 at 9:42pm
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The more that I think about this, I am positive that you are correct. The yellow just means, "I am not guiding you" Not, "I don't know where we are". Once the Flight plan is activated. It goes green. Thanks. Ken |
Posted By: LANCE
Date Posted: 01 Apr 2017 at 10:13pm
10.1.3 fixed a GPS lock issue for some people depending on location. 10.2 should take care of it for sure
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bcool wrote:Posted By: MysticCobra
Date Posted: 02 Apr 2017 at 7:02pm
Yes, that's correct. One way to tell at a glance that the IFD has a good GPS lock is when you start to taxi and the TRK changes from a red X to a number matching your taxi direction. Since that number is derived from trending GPS location fixes over time, if that number makes sense, then the IFD is getting good GPS solutions.
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