GNS430 to 430W upgrade install

[RhinoDrvr]

Hello,

I my GNS430 should be coming back soon as a GNS430W from Garmin. My understanding is that the reinstall should be as simple as;

1. Remove and Replace the GPS antenna with the included WAAS unit.
2. Replace current cable from antenna to 430 with an RG400 cable.
3. Slide the 430W into the current tray.
4. Enjoy the increased climb performance from a lighter wallet.

Are there any other steps to complete the install? I can?t find any instructions anywhere for upgrading from a 430 to 430W.

Also, is there any issue with flying the box for a few hours before replacing the antenna and coax? I?m planning on going to OSH and would like the second radio, and can do this work immediately post OSH.

[BobTurner]

While you?re behind the panel, ask if you need any more connections long-term. Easier to do now. For example, you can now use the 430W as a position source for ADSB-out. But you?ll need a wire from an unused RS232 output pin on the 430W.
I do not know the answer about using the old antenna. It?s not simple-the new antenna gets power up the coax.
I am surprised the original coax is not already RG400.

[tim2542]

FYI Garmin does have a minimum length for the antenna coax, it?s for attenuation purposes, they require 3 to 7 dB. Page 3-10 in the install manual. It was pretty long as I recall.

Tim Andres

[RhinoDrvr]

My current cable is 9? long, as the antenna is on the glareshield. Isn?t there some type of attenuator that could be installed in the cable so that I don?t have 13 feet of cable coiled up behind my panel? That seems like a very sloppy solution.

[BobTurner]

Originally Posted by RhinoDrvr

My current cable is 9? long, as the antenna is on the glareshield. Isn?t there some type of attenuator that could be installed in the cable so that I don?t have 13 feet of cable coiled up behind my panel? That seems like a very sloppy solution.

Yes, you can buy in-line attenuators. Good quality ones are more expensive than RG400. Also there is a specified insertion loss for every connector.

As you probably know a glare shield mounted antenna is not in compliance with the TSO.

[AlexPeterson]

Also in the install procedures is to verify through a range of com transmissions (of all on-board radios) that the gps signal is not corrupted. This is what often leads to needing a longer coax than is physically necessary, as I understand it.

[FasGlas]

For what it's worth, some people I know have swapped out their 430 to a 430W and didn't change anything, works just fine. I'm sure if you're looking for the installation to be certified than you'd have to change the antenna, cable and flights.

[RhinoDrvr]

Originally Posted by BobTurner

As you probably know a glare shield mounted antenna is not in compliance with the TSO.

I was not aware of that. Where would I look to find the specifics of the GNS430W TSO? Is there a document I can reference?

[BobTurner]

Originally Posted by RhinoDrvr

I was not aware of that. Where would I look to find the specifics of the GNS430W TSO? Is there a document I can reference?

For the TSO to be valid you need to install it in accordance with the Garmin installation manual. You can find it on the internet if they don’t give you a copy. The only approved antenna locations are all external. That doesn’t mean a glareshield location won’t work - but it’s up to you to show that that location meets all the TSO specs and tests.

[RhinoDrvr]

How does that process work? Can you fly IFR if the avionics are not installed per the TSO, yet function 4.0? Where would I go to get smart on that?