garmin 375 w transponder - v gt345

[DKirkpatrick]

Hello. So... looks like the 375 with the all in one transponder looks hard to beat.
Is the transponder in this unit functionally the same as the gtx345? Do I forgo anything by not putting in a 345 and a separate gps?
THANKS!

 

[WDD]

What do you need? If you don't have an ADSB transponder, don't have a GPS navigator, but have good coms and nav radio already, sounds like it would be a great fit.

The only thing I can think of is the GTN 650 with its com and nav could be easier on switching between VLOC or GPS.

The GTX 345 and GTN 650 combination is a bit more expensive than the 375. To make it apples to apples you'd also have to add in the cost of a FightStream 510. Double the cost?

 

[NordicDave]

If you have or planning on having a standard nav/comm GPS like IFD-440/GTN-650/etc, then the GTX-345 is an excellent choice. If no new plans for GPS or don't have one presently, then GNX-375 is a stellar solution.

One key difference is screen sizes between GPS options; also the GTN-650 needs a FS210/510 for iPad connectivity where IFD-440 or GNX-375 does not.

 

[asicer]

Is the transponder in this unit functionally the same as the gtx345?

More or less.

Do I forgo anything by not putting in a 345 and a separate gps?

As @WDD points out, what you lose is mostly on the GPS/NAV/COM side and not the transponder side. Besides VLOC switching there's several things that a GTN can do that a GNX cannot.

 

[Doug States]

Assuming you are doing this to get ADS-B.... keep in mind, if you go with the GTX-345 to get ADS-B you will need to already have a GPS source, or buy the more expensive version of the GTX-345 with the built in GPS source. The added expense to add the GPS source put me over the fence and I went with the GNX 375.

 

[DKirkpatrick]

kinda starting over in this airplane. has an old n/c, old transponder, no ads-b capability. I keep thinking the 375 kinda takes care of ads-b in and out, plus a new gps source for GPS-based approaches.
ALSO — seems like the installation costs, which are a big factor, mean it MAY be cheaper to install this all in one unit? (MAY?) Rather than a gps and as transponder. Plan to install a king KN53 and KY197A... largely because I've flown with these for years and they seem bulletproof, and the King KY comm has alot of output, as compared to some of these other Comms. Have mountains, and like to be able to communicate...
Thanks for the help.

 

[Doug States]

I had a plane with old transponder and no attitude indicator or DG. I wanted to get it IFR capable in the future. I debated a GTN 650 with GTX 345 and dual G5's, but I wasn't able to pay for that all at once. I considered waiting on the GTN650, but then I didn't have a GPS source so it made the GTX 345 more expensive. I chose to go with dual G5's and the GTX 375 now and that just leaves me needing an updated nav/com in the future if I want ILS and LOC approaches. I can go with a GNC 255 in the future to get that and it can also drive the G5 HSI. So my total cost is lower and it was easier for me to spread it out and get ADS-B now.

So just for parts (not including G5's) I chose a GNX 375 and GNC 255 for a total of ~$12,500 (list) compared to a GTN 650xi and GTX 345 for a total of ~$17,500 (list) and have similar capabilities (not identical, but close). Plus with the GNX 375 it will bluetooth to my ipad without paying for Flight Stream.

I know this is specific to my situation, but I figured I might not be alone.

 

[chemgeek]

A GNX-375 means one GPS antenna for both the transponder and RNAV functions, which is a nice benefit. The downside is if this unit fails you lose BOTH transponder and GPS NAV. But it's a clever way to take care of two upgrades at once. I think a GNX-375 and a GNC255 with a suitable CDI would make for a terrific little IFR panel. (Put a couple of G5s in to drive your favorite AP and you have a real winner.)

My upgrade arc was too early to take advantage of these options, so I have a hodgepodge: GNS-430, GMA-340, NGT-9000, G5s, STEC-20 AP, and a legacy Terra NAV/COM/CDI for backup. And thus two GPS antennas. The GNS-430 will eventually transmogrify into an IFD-440 and the Terra units will morph into a GNC-255 which will reunify with my removed GI-106A. The IFD equipment plays really nice with the NGT-9000. One challenge with avionics upgrades is ensuring all the equipment, and potential future upgrades, will be able to talk to each other sensibly. But what I have works for now and has me covered for both RNAV and ILS with backup. I can't believe all the stuff I've removed and basically thrown away or red-tagged over time. I still have an Apollo 612 LORAN paperweight. It was revolutionary at the time...

 

[asicer]

I can't believe all the stuff I've removed and basically thrown away or red-tagged over time. I still have an Apollo 612 LORAN paperweight. It was revolutionary at the time...

I suppose there's something to be said about replacing equipment that's well past its prime but still has resale value...

 

[PPC1052]

kinda starting over in this airplane. has an old n/c, old transponder, no ads-b capability. I keep thinking the 375 kinda takes care of ads-b in and out, plus a new gps source for GPS-based approaches.
ALSO — seems like the installation costs, which are a big factor, mean it MAY be cheaper to install this all in one unit? (MAY?) Rather than a gps and as transponder. Plan to install a king KN53 and KY197A... largely because I've flown with impatiently these for years and they seem bulletproof, and the King KY comm has alot of output, as compared to some of these other Comms. Have mountains, and like to be able to communicate...
Thanks for the help.

We have the GNX 375 and I love it. You will need to have compatible indicator(s) if you want IFR navigation. So factor that cost in, too, if you don’t already have compatible indicators. We chose dual G5s.

 

[WDD]

Here's a thought. Garmin likes to play with other Garmin, not so much others. If you're "kinda starting over in this airplane", suggest exploring getting a Garmin HSI and and Garmin nav/com. Heck, why not a Garmin 275 HSI? Thinking about future scalability, and avoiding any issues with compatibility.

 

[David Megginson]

Hello. So... looks like the 375 with the all in one transponder looks hard to beat.
Is the transponder in this unit functionally the same as the gtx345? Do I forgo anything by not putting in a 345 and a separate gps?
THANKS!

I bought a GTX 345 and GTN 650 in 2017. They're great units, but I would have gone with the GNX 375 in a heartbeat if it had been available then, and saved (probably) 10 AMUs or more when I factor in installation costs.

If you have a huge avionics budget, then then go ahead and order a custom-cut aluminum panel, a new autopilot, fancy glass PFD and MFD, 3D audio panel, dual GPS navcoms, etc. etc. But if you're looking to get ADS-B in/out and WAAS RNAV on a budget, just keep your existing navcoms and slide the 375 into your transponder slot. Unlike the GTN 650, the GNX 375 also comes with wireless built in (so you won't even need a FlightStream 520).

 

[Tennis]

Just take off

 

[Pinecone]

What do you need? If you don't have an ADSB transponder, don't have a GPS navigator, but have good coms and nav radio already, sounds like it would be a great fit.

The only thing I can think of is the GTN 650 with its com and nav could be easier on switching between VLOC or GPS.

The GTX 345 and GTN 650 combination is a bit more expensive than the 375. To make it apples to apples you'd also have to add in the cost of a FightStream 510. Double the cost?

GTX-345 has BlueTooth built in for ADSB In and FISB..

You would only need FS510 if you wanted to do wireless database updates.

 

[Pinecone]

A GNX-375 means one GPS antenna for both the transponder and RNAV functions, which is a nice benefit. The downside is if this unit fails you lose BOTH transponder and GPS NAV. But it's a clever way to take care of two upgrades at once. I think a GNX-375 and a GNC255 with a suitable CDI would make for a terrific little IFR panel. (Put a couple of G5s in to drive your favorite AP and you have a real winner.)

With a GTN-650Xi and STX-345 you will still only have a single GPS antenna. It will be connected to the GTN and that will feed the GPS info to the GTX.

For long term, the GTN-650Xi is a better basis for a panel. One big difference between the GTN-650 and GNX-375 is that the 375 is a 2" box and the 650 is a 2.6" box. So the 650 screen is larger.

A 650 and 2X G-5 or G-275 make a great IFR platform. Heck, on friend has two 10" G3X and a 650Xi in his Mooney.