R

Robert Anglin

Well Known Member
Just a water cooler type of question to those who have added the GPS-20A box to their G3X system without having another WAAS box in the system.
We are looking at the merits of adding the 20A before 2020 and would like to hear how others are getting along with this new box and what they are getting out of it other than compliance to the 2020 rule. Are we seeing any improvements other than best position reporting? Is It worth it to add before 2020? We are not going to try and put a GNT-650 in the panel if we don't have to as that type of cost is not merited by the type of flying we do any more. Thanks for the thoughts up front. Yours as always, R.E.A. III #80888
 
Well, the GPS 20A works as advertised with the GTX 23 - passed the FAA system test today. I don't see any difference compared with the built-in GPS in the GDU 46x. Once the GPS 20A is installed, it becomes the primary GPS source - the GDU GPS is not accessible / switchable as an alternate source. I assume that it becomes a failover source if the GPS 20A goes offline.

I was originally going to wait until 2019-ish and buy a GTN, but then the FAA decided to exclude aircraft with non-compliant position sources from completely participating in the system in 2016. That basically forced my hand because I just spent a ton of AV$ on a new G3X system, and not having a fully operational ADS-B system would PMO.
 
marcusadolfsson said:
Where did you buy the GPS 20A? Not seeing in stock at lot of places.
Click to expand...

Hello Marcus,

Looking at our inventory this morning, I see we have a healthy stock of 010-01546-00 GPS 20A units, so any of the Garmin dealers should be able to fill your order pretty quickly.

Thanks,
Steve
 
GA-35

Thanks Steve, we just cut a mount spot for the GA-35 antenna back on the hat-rack inside the canopy frame area. If I understand it correctly the foot-print of the GA-35 is the same as the GA-56 and we can use that as a template to drill the holes For the GA-35. We had put a GA-56 on top of the front baggage area skin to feed the GDU-460 in the panel and will be leaving that antenna there and hooked-up to the GDU. The GA-35 I think is required to be used with any of the WAAS boxes as it is certified for WAAS use and the GA-56 is not. Just checking here, is this all correct? The mount holes, the GA-35 required that is or can a 56 be used in an experimental? Others may get something out of this post as well.
Yours as always. R.E.A. III #80888
 
Thanks Steve.

"The GPS 20A requires the installation and use of a GA 35, GA 36, GA 37, or equivalent GPS/WAAS antenna"

Do you know of any tiny equivalent antenna. This is for a VFR Cub so rather not slap a GA 35 on it...
 
Robert - As identified on page 13-1, the list of approved antennas for the GPS 20A does not include the GA 56. Yes, the mounting holes should be the same, but we don't recommend you drill holes in your plane until you have the antenna in hand that you wish to install.

Marcus - Sorry, the performance requirements are so strict that we don't have a "tiny equivalent antenna" like the GA 26C that can be used with the GPS 20A. Page 13-3 does say "or equivalent antenna", but currently the 3 listed are all that we recommend.

Thanks,
Steve
 
You must log in or register to reply here.