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Garmin G5 external GPS antenna needed?

Lenny Iszak

Well Known Member
I'm installing a Garmin G5 in my RV-10 and wondering is the unit's internal GPS antenna adequate or do I need to connect an external one?

Thanks,
Lenny
 
If you've got the latest software, it does pretty well without the external antenna. I have the antenna sitting on a shelf, ready to install - but just haven't gotten around to it due to the good performance of the internal antenna.

The previous software versions were not nearly as good in this regard.
 
Two G5s installed without antenna about 8-months ago in my RV-6.

The GPS in the unit works great.

IF doing aggressive maneuvering (60 bank turn or more) GPS will lose signal for a few seconds. Because I have a magnetometer, I get a RED X through the ground speed as that comes from the GPS portion of the G5. This is not a big deal to me or my installation.
 
Thanks for all the replies! I will try it without a GPS antenna first and see how it works. I'll report back.

Lenny
 
I'm installing a Garmin G5 in my RV-10 and wondering is the unit's internal GPS antenna adequate or do I need to connect an external one?

Thanks,
Lenny

Hello Lenny,

It is rare to see the G5 internal GPS receiver/antenna work well enough in metal aircraft to not need an external antenna, but you can use the GPS Configuration page in config mode to tell you if your installation is adequate.

The G5 has a very sensitive WAAS GPS receiver, and will almost always have enough signal to receive a 3D or 3D Differential fix to be able to determine and display the basic track/speed/altitude information, but having the high quality signal necessary for the G5 to use GPS data to improve the attitude measurement is something quite different.

Here is an example where the GPS antenna is working well enough to provide the basic GPS data on the display, but not working well enough to provide a signal of sufficient quality to correct attitude sensor drift (no green check mark).

FPzXhNMQGgI6c6TjwTlu6iMPtqLGawy_dUi68yVIT2SJUVVjBHhT3bZ8vuf_8mRbUYBH696nDE4ymLBJ-wnC9TbiAtpTgIOgUGRr-nXw89cfBFzzoVlHvisT0fApRNhDhoKQ89hUzIYU6v78LS24NsToB7LvYtCvJzfZkM2L3HU6VkxChls6H9zspjivO0aIqjATaAlRUPO3nn5qTjsK_cTVFv7OuElV4OAL4Afrf77_LceixInT9GblNDEkH4oSLnHN11jovYxSRMUBv2K57UrDMxvGqvIFiDCg0Y2REVFJw9InHTmcDi_uaQk9cbBCLG157ahyIet6eOUhhq81_y5ZmD2kJPOSsbTgApQBnB9cESW33_BChV6KEl6ITARuKRwRUw3SUmJObLWhsAaUODCXfGIogu0WJr7-craxs3YM2G6shwOBNQfW6dC15w1a_B4WxvsniGSFE7OuVb8jaJCr8UQoykdd9mjkr53oEgGLfdTBirYHPXumUHG7lPxJNEKaxxfmngNieMZMEKLolMhnWkCc52uTH1PIAARraZQygIFx_HDiedgZigPAiwjS2W6wUI-UZ7JQLOSVvNR7bFRK0DSAZYr7cjqgPlpqTIYylwVZHbzTlj1LUj4whSmrDycrutkBFFYBZ83muxzL0y4SxktOUUM=w320-h240-no



The G5 can operate without a GPS, but for the best performance, this is what you want to achieve with your installation, especially if used in IMC. The green check mark shown on the GPS configuration page is an indication that you have a good installation.

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For certified installations of the G5, we require an external GPS antenna in all installations where the G5 is not receiving GPS data from an external IFR navigator.

Thanks,
Steve
 
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Steve,

Thanks for that! I'll install it and check how many green bars I get, especially in maneuvering flight like Gary mentioned above. Just didn't want to add one more GPS if I didn't have to, I already have 5 in the plane. :D
 
Too bad one can not share the signal from an existing antenna to multiple devices, like using a splitter type.
 
In a G3X installation does that required GPS data come from the MAPMX or the CAN bus? Or is it best to still have an antenna on the G5?
 
I needed an external antenna

Have the G5 mounted top center on my panel (RV9 tip up). Could not get a reliable signal without an external antenna.
 
Too bad one can not share the signal from an existing antenna to multiple devices, like using a splitter type.

Oh but you can. GPS splitters exist and work PERFECTLY. I've been running a 1-2 splitter for over 2 years without an issue.

DSCN4711.JPG


And to get back OT - I have a G5 mounted at the bottom of my panel and it seemed to work fine as long as I had shallow banked turns. Anything last 45 degrees would cause the signal to be lost. I linked the G5 to an external antenna and it's been rock solid since.
 
In a G3X installation does that required GPS data come from the MAPMX or the CAN bus? Or is it best to still have an antenna on the G5?

Hello Walt,

Yes, using MapMX from a GNS/GTN or using GPS data from the G3X/G3X Touch displays over the CAN bus are additional ways of getting high quality GPS data to the G5.

Using these external sources of GPS data does, however, place some reliance on these external sources and reduces the independence of the G5. Increased independence can be achieved by adding an antenna to the G5.

It isn't uncommon for a G5 in a G3X Touch system to have 3 sources of GPS data (internal GPS receiver, MapMX from GNS/GTN, and CAN bus). The G5 prioritizes the internal GPS receiver above all other sources when the signal is good.

Thanks,
Steve
 
Q. For Steve, G3xpert

Steve, if I am using a G5 as an independent back-up instrument without any other electrical connections in or out to any other data source, how important is the GPS function?

Is it simply an automatic backup if the pitot pressure fails?
 
Steve, if I am using a G5 as an independent back-up instrument without any other electrical connections in or out to any other data source, how important is the GPS function?

Is it simply an automatic backup if the pitot pressure fails?

Hello Gil,

The simple answer is yes, having a source of GPS data, internal or external, is important to allow the G5 to perform at it's maximum potential.

While the G5 is not TSO'd, we designed the G5 to meet the TSO-C201 performance requirements.

The TSO-C201 performance requirements are specified for both "normal" mode and "degraded" mode. Each manufacturer is allowed to define what is normal mode for their product, and for the G5, normal mode relies heavily on GPS data for maximum performance to avoid being dependent on air data which could suffer a blocked pitot. One of the reasons we designed a high performance WAAS GPS receiver into the G5 was so it could independently perform at the highest level with no reliance on external GPS sources.

The G5 meets these performance requirements both with GPS (normal mode) and without GPS (degraded mode), but the accuracy requirements for degraded mode are a little less stringent.

Thanks,
Steve
 
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