G3x GPS antennas

[SteveL]

Good morning,
I'm presently wiring my 2 screen G3x touch. I have a GTN 650 that will drive the system. According to the Garmin install manual it appears that I will need 2 GPS antennas. One to drive the 650 and one for the PFD. Am I looking at this correctly?
Thanks in advance!
SteveL

[BrianDC]

Nope, that sounds correct. G3X needs it own GPS antenna for it's internal calculations, moving maps, etc. GTN need the same.

[Walt]

I recommend an antenna for each screen, the GA26 is pretty inexpensive and sits on top of the glare shield unobtrusively.
If you have a G5 add another one for that.

[Ed_Wischmeyer]

Originally Posted by Walt

I recommend an antenna for each screen, the GA26 is pretty inexpensive and sits on top of the glare shield unobtrusively.
If you have a G5 add another one for that.

The G5 has its own antenna built into the bezel, so you don't need an external antenna. For certified aircraft, yes, for experimental, no.

[g3xpert]

Originally Posted by Ed_Wischmeyer

The G5 has its own antenna built into the bezel, so you don't need an external antenna. For certified aircraft, yes, for experimental, no.

Hello Ed,

This isn't entirely true.

All aircraft will want to verify their G5 is receiving a good GPS signal, and it is easy to do. See this posting.

While we are discussing G5, it is a good time to remind everyone to make sure their software is up-to-date. The current version is V6.10.

G3X and G3X Touch systems with a G5 will automatically keep the G5 updated as new system software is loaded, but for standalone G5 installations, the user will need to download and install the software.

Thanks,
Steve

[jliltd]

Originally Posted by Ed_Wischmeyer

The G5 has its own antenna built into the bezel, so you don't need an external antenna. For certified aircraft, yes, for experimental, no.

Ed. You are right. But that used to be the case. Starting with V16 of the type certificated G5 STC manual external GPS antennas are not allowed for the G5 (i.e. no GA35/56 etc.). Only the cheaper GPS glareshield versions are approved, like the one Walt alluded to. Also in this same revision standard MIL spec twisted pair wire cannot be used for the CAN bus. There is some specialty signal wire to be used with the addition of resistors and diodes inline.

That's not an April Fool's joke. It's already June. Aren't we glad we don't have to follow the STC install manual on experimental aircraft? Naturally I am in the midst of a Comanche install that is wired with the obsolete stuff. Thank goodness I haven't installed the GA35 GPS antenna on top of the fuselage yet.

Steve. You may want to update your linked post above to reflect the fact type-certified aicraft can no longer use an external GPS antenna for the G5.

Jim

[g3xpert]

Originally Posted by jliltd

Steve. You may want to update your linked post above to reflect the fact type-certified aicraft can no longer use an external GPS antenna for the G5.

Jim

Hello Jim,

The G5 has a built-in internal GPS antenna.

An external antenna is an antenna that is external to the G5 unit and connects to the BNC connector on the back of the unit whether it be mounted on the glare shield or on the exterior of the aircraft.

Certified aircraft are required to use an external GPS antenna, not the internal GPS antenna.

Thanks,
Steve

[jliltd]

Aha. The devil is in the details. Symantics. The only time external would be one in the same would be when installing a G5 in an open cockpit biplane. 😉. Thanks for the clarification. Duh.

Jim