upgrade... kind of

[Maina]

I am looking at adding 2-G5's and gfc 500 to my 182P. It has existing 430W which I like and keeping, it has GTX 345, and old kx 170B that comm works and nav doesn't. I am thinking of swapping KX for GNS 420(nonWAAS) as it is same price and new comm plus it would have gps back up capability if 430W takes a dive in flight. My questions are: would it tie into same antenna or would I have to add another? would the 430W crossfeed into 420? and would they both tie into g5/GFC500 to use either one for GPSS/Nav funcitons. Thank you in advance for your help.

 

[Ravioli]

would the 430W crossfeed into 420?

Most likely NO. Even in the 530/430 models both must be WAAS or Non-WAAS for the crossfeed to work.

 

[Martin Pauly]

Cross-fill between WAAS and non-WAAS for sure doesn't work.

As for antennas, my understanding is that the WAAS antenna is different from the non-WAAS antenna. Even if the 420 and 430W could be connected to the same GPS antenna (your existing one), I'd think twice about doing that because then you'd have a single point of failure that can knock out both GPS units.

- Martin

 

[GRG55]

Crossed between WAAS and non-WAAS for sure doesn't work.

As for antennas, my understanding is that the WAAS antenna is different from the non-WAAS antenna. Even if the 420 and 430W could be connected to the same GPS antenna (your existing one), I'd think twice about doing that because then you'd have a single point of failure that can knock out both GPS units.

- Martin

^^^ This.

Can't share antenna. The WAAS is a different one from the non-WAAS as Martin has noted.
Can't crossfill between WAAS and non-WAAS.
Check, but suspect non-WAAS can't interface with your G5 either (I know non-WAAS will not interface with the GI 275 I am going to install).

 

[Maina]

Thank you all for your help! Guess I will pass on the 420 and wait to upgrade #2 another time

 

[Rebel]

Just for reference: Sold my GNC 420 WAAS last month for $3,400, with tray, no connectors, no antenna. Cheap because the market for GPS/COM units is way smaller than the one for GPS/COM/NAV units.

 

[Maina]

Rebel, that is exactly why I was looking at the 420. Seems like a back up gps com would be more useful than a nav/comm when #1 430w goes on the fritz in the middle of IFR flight. Where I live the VORs are few and far between and dropping like flies. GPS is becoming not only more useful but necessary. The idea was to have two units that tie in to G5’s and gfc500 to maintain navigation if one goes out rather than switching to hand flying vors that are not really available in my area. Thank you for your input. I appreciate any help with my decision!