G5 external antenna?

dreed · #1 03-26-2023, 10:56 AM

I am 95% sure I am going to add a G5 as a backup in my panel. I have a slider, and while the G5 will be mounted high I still am concerned about poor GPS reception and plan on adding a glareshield antenna.

My question is- do I really need the $230 Garmin unit or will a good quality GPS do just fine? Doesn't seem to be anything special about their unit other than the name embossed on it, but I am willing to be convinced otherwise.

Thanks in advance-
dan

Bavafa · #2 03-26-2023, 11:23 AM

Garmin GA 26C is around $90-$100 and works excellent.

Some say that the G5 does not need a GPS antenna but in a RV that has lots of metal parts above the instrument, in my opinion, will be required for a reliable operation.

dreed · #3 03-26-2023, 11:31 AM

Perfect- thank you!

RV6_flyer · #4 03-26-2023, 12:27 PM

Been running two G5s for over 6-years without external GPS antenna.

The only time I have lost GPS signal is when doing very hard maneuvering. Think Lazy 8, chandelles, or acrobatics type maneuvers when direction changes rapidly.

IF there were an issue with GPS and the G5, I would have added one already.

MacCool · #5 03-26-2023, 01:48 PM

I bought a GA-26C antenna from eBay for $35 a couple of years ago. Works fine, but I primarily use it connected to my IfD 440 since I don't really need an another GPS device in the cockpit. In my airplane, the built-in antenna on the G5 didn't really do the job reliably.

phloidtrout · #6 03-26-2023, 08:23 PM

I've had a G5 in my RV6 for a few years with no antenna, and have had no issues.

Traash · #7 03-26-2023, 09:54 PM

GA 26 if it's installed inside (glareshield, etc).
The GPS in the G5 is used for attitude stabilization by the internal ADAHRS. It's NOT used for navigation. Unless you monitor the GPS page (in the congig mode) how can you say it works properly.
External antenna in an aluminum airplane is a simple 100% sure way.

Southern Pete · #8 03-27-2023, 07:47 AM

I have an aftermarket remote antenna with a BNC connection that works well.

Dan 57 · #9 03-27-2023, 09:41 AM

Quote:

I've had a G5 in my RV6 for a few years with no antenna, and have had no issues.

Same here... but with issues

Had the PFD G5 on my dual install go into Alignment during a flight a couple of weeks ago, whilst doing turns in moderate turbulences. Luckily in VMC...
I had, for operational reasons, pulled the CB of my GNX 375 which is equipped with a GA35 WAAS antenna.

Related the incident to GX3 Experts who advised me, as Traash already mentioned above, that the G5 needs a GPS signal for stabilisation.

I've had the same problem already once a few years ago, also in lengthy (20') moderate turbulence conditions, with a single G5 and before the GNX install... my conclusion is that the installation of the G5 in a normal position on the panel of an RV will not guarantee perfect GPS signals at all times, and should be augmented with an external antenna.

IMC flyer beware!

g3xpert · #10 03-27-2023, 11:57 AM

The G5 uses GPS data as one input to correct for sensor drift for its on board ADAHRS. There are multiple inputs that correct for sensor drift, so if you lose GPS, you would not have a problem as long as the others remain. You can run into a problem if you lose more than 1 input however. By adding a GPS antenna to the G5 you are giving the unit the best chance to receive a strong GPS signal at any given time; this is a step you can take to lessen the likelihood that you find yourself in a situation in which more than 1 input is unavailable.

The GA 26X Antenna (010-13287-00) is a low-cost unit that can be used as a glareshield mounted antenna for your G5.

Thanks,

Justin