A couple of GTX-335 questions

Salty

Salty

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Salty
I'm trying to decide between that and a GDL-82.

I've currently got a G5 AI, KT-76 transponder and a GDL 39R for "IN". I have no in panel GPS.

My questions are:

1. It looks like it doesn't come with an encoder standard, can anyone confirm I will have to use my current encoder, and / or what the garmin encoder costs?

2. Can I hook the antenna I'm currently using for the G5 to the GTX-335 and then feed the G5 from there via RS-232 without adding a second antenna?

Ok, third bonus question, same as #2 only for the GDL-82, can I use G5 antenna for it and then feed the G5 from there?

I can't see spending the extra money for the GTX-345 to get the same functionality I'm getting from the GDL-39 since I already own it, anything I'm missing there that justifies that cost? I also considered the Lynx, but again, not really anything more than I already have other than it being in the panel (on a much smaller screen than my iPad). If it worked with Garmin pilot also, I'd probably consider it. I have to use the iPad for GPS for now anyway, so I think it's better to have the traffic and weather integrated into that interface.
 
If you buy the promotional 335 kit over the counter from somewhere like Spruce, it comes with the GAE12 encoder. You don't have to use it, you can use your current encoder if you like (though depending on what encoder you have, you might be well served to upgrade it). Depending on what antenna you are using for the G5 you can use that as long as it's on the list for the 335 (e.g. GA 35, GA 36, GA 37 ... but _not_ GA 56) and the STC does approve sending GPS data to the G5 from the 335.
 
I used a GA35, so I guess I could use it. Still have to justify the extra grand.
 
Raymo said:
I'll be more clear, then. You can't do it the other way around. The G5 is NOT a certified WAAS GPS source.

You're welcome.
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I just wanted to make it clear that I was never asking about that direction, I'm aware you can't do that already. Just for clarity.
 
Ryan Klems said:
The promotional kit also comes with a GA 35, so you could sell that pretty easily for $250-300.
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That and what I can get for the old transponder and encoder would almost make up the difference. Nice. Would probably be easier to install as well without having to deal with another antenna. Unless I can do the same with the GDL-82........
 
Salty said:
That and what I can get for the old transponder and encoder would almost make up the difference. Nice. Would probably be easier to install as well without having to deal with another antenna. Unless I can do the same with the GDL-82........
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The current G5 STC install manual has no mention of the GDL-82 as an approved position source, and I don't believe it can output MapMX data currently anyway. Who knows what could happen in a future software update/install manual revision though, but for right now, no.
 
Ryan Klems said:
The current G5 STC install manual has no mention of the GDL-82 as an approved position source, and I don't believe it can output MapMX data currently anyway. Who knows what could happen in a future software update/install manual revision though, but for right now, no.
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I didn't think to look in the G5 install manual. Duh.
 
Salty said:
I'm trying to decide between that and a GDL-82.

2. Can I hook the antenna I'm currently using for the G5 to the GTX-335 and then feed the G5 from there via RS-232 without adding a second antenna?

Ok, third bonus question, same as #2 only for the GDL-82, can I use G5 antenna for it and then feed the G5 from there?
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Yes and yes

Extra bonus. If you have a 406 ELT, you can use the GDL82 as a position source for that as well.
 
Mtns2Skies said:
Yes and yes

Extra bonus. If you have a 406 ELT, you can use the GDL82 as a position source for that as well.
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You are saying you can feed an ELT and a G5 from the GDL82 at the same time?
 
Salty said:
You are saying you can feed an ELT and a G5 from the GDL82 at the same time?
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Hmm, now that I'm not sure of. I would imagine so but am no authority on the matter.
 
Mtns2Skies said:
Hmm, now that I'm not sure of. I would imagine so but am no authority on the matter.
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I would guess not as RS-232 wouldn't support multiple connections from one port.
 
IIRC....there are more than one serial outputs and inputs....so there are opportunities to mix and match inputs/outputs.
 
Hmmm. If your transponder fails then your AI stops working? Maybe a bad idea. I guess the AI would still work, you just wouldn't get headings and ground speed?
 
Salty said:
Hmmm. If your transponder fails then your AI stops working? Maybe a bad idea. I guess the AI would still work, you just wouldn't get headings and ground speed?
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It will still work, but that is a valid question and it has been said by Garmin themselves, the best way to install it is with its own GPS antenna AND wired to a separate GPS receiver, even tho they do not show both connected at the same time.
 
I wouldn't even bother with the GDL 82 with an old transponder. It makes sense if you have a newer more stable one like a Garmin GTX327.

Keep in mind that using a G5 with only an antenna (whether through the 335 or direct) doesn't provide you any navigational information, it simply drives the ground speed and ground track on the G5. If you want more you'll have to have some type of GPS, whether panel mounted (430) or portable (Aera 660). In my C120 I plan to use the Aera 660 and GDL 39 with my G5.
 
Labor cost of AXP340 might be less than any other ADSB out transponder for you since it slides in the tray of the KT76? But may not be what you want..,
 
455 Bravo Uniform said:
Labor cost of AXP340 might be less than any other ADSB out transponder for you since it slides in the tray of the KT76? But may not be what you want..,
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Mine is not a KT76A, just plain KT76, so I don't believe that helps any.
 
I wish I knew about the GAE12 when I had my 335 installed.
 
Doug Reid said:
I did exactly that in my Cessna...removed an old Narco AT-50, installed a GTX327 and GDL-82. I helped a friend install a GDL-82 in his Cherokee...his Narco AT155 transponder still works very well and his ADS-B test flight passed on the first attempt. It all depends on your budget. If you have a good working transponder that passes a standard ramp test, that is all Garmin requires for a pre install check for the GDL-82. . Bur I agree in the long run you might want to install a solid state transponder. You can pick up a GTX327 for about $450.
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I see this as a very good recipe for installing a solid solution for compliance to an older panel while doing it on a tight budget.
 
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