GTN750 - connect transponder or not?

DesertNomad

DesertNomad

Pattern Altitude
Joined
Jul 5, 2013
Messages
2,442
Location
Northern NV
Display Name
Display name:
DesertNomad
I have a GTN750 being installed and already have a GTX330.

Is there any advantage to not connecting the two units so that I can use the top two spaces on the GTN for user data instead of Ident/XPDR?

I assume if I do connect the two devices, I can't reconfigure the two spaces at the top for other user-data from the GTN menus.
 
Are you upgrading the 330 for ES to be ADS-B Out compliant as part of the upgrade? If so don't you have to get the WAAS position source from the/connecting to the 750?
 
A GTN can be wired to a transponder without enabling remote control capability.
 
bnt83 said:
A GTN can be wired to a transponder without enabling remote control capability.
Click to expand...

I guess then what I am asking is about not connecting remote control capability so as to free up 2 cells on the GTN interface for user data,
 
DesertNomad said:
I guess then what I am asking is about not connecting remote control capability so as to free up 2 cells on the GTN interface for user data,
Click to expand...

These are two seperate issues. You can wire the GTN to a transponder to share data and still not enable remote control. Remote control is simply a configuration option in the configuration menus. My understanding is that transponder control "cell" "window" "key" whatever you call it is only present when remote control is enabled. That empty space should be a user definable.

If you look hard enough on google images you will find multiple different things displayed were that transponder control key normally is.
 
Last edited:
I have a 750 installed and find the top two rows of data invaluable. For that reason alone I opted for a dedicated transponder.
 
My avionics guy said that while it is a configuration change on the 750, the wire should be removed as well according to Garmin.
 
Lol, more than one way to skin a cat. You can RS232 pressure altitude encoder directly to the GTN and then RS232 that to the transponder. You have an option of sending GPS data & pressure altitude and remote control or just the data through that wire. I don't think ADS-B out would work at all with the wire removed....

Most owners would just drop off the airplane and pick it up when they are done and not bother to understand the interfaces.

In my case I wired pressure altitude to both the GTX345 and the GTN650. The GTN sends pressure atitude to the GTX. The GTX decides which one to use.
 
Last edited:
There is no flagged note on the dual GTN w/ single GTX-33X drawing that says the wire can only be installed when remote control is enabled so I don't know where they got the wire must not be installed. That's just odd.

I did mine via field approval but capped & stowed spare RS232s for the coming G5 displays, all the backlighting control wires, and some other stuff. The FAA got all my wiring drawings and never asked anything about it. That one went to the Wichita ACO (IIRC)
 
Last edited:
You must log in or register to reply here.
Back
Top