GTX 345 - with or without Garmin altitude encoder

[WannFly]

Kate is in the shop getting GTX 345 R... i am wondering if there is any benefit of installing Garmin altitude encoder? the avionics guy sayz no but... trust but verify ... what does POA say?

on a related note @azure is everything working for you with GMX 200 + 345R set up?

Edit: i went with 345 panel mount

 

[asicer]

Kate is in the shop getting GTX 345 R... i am wondering if there is any benefit of installing Garmin altitude encoder? the avionics guy sayz no but... trust but verify ... what does POA say?

My opinion is that it depends on what you have for an existing encoder and how it's hooked up. If the old one is big, heavy and uses Gray (Gillham) code, go with new. Incremental cost to modernize towards smaller, simpler and fewer wires. On the other hand, if you are running short on RS232 ports, keep the Gray/Gillham one.

 

[GeorgeC]

If the old one is big, heavy and uses Gray (Gillham) code, go with new. Incremental cost to modernize towards smaller, simpler and fewer wires.

I can't speak for the 345R, but had I known about the Garmin encoder nugget when I had my 335 installed, I would have done it for the above reasons.

 

[simtech]

I have it in my GTX345 non R install. It is also the config module, which I didn't have. The Avionics guy said its the most accurate encoder he has dealt with. Plus you do not need to disconnect the static line when you remove the TXP.

 

[Ryan Klems]

Plus you do not need to disconnect the static line when you remove the TXP.

That statement has never made any sense to me. I've yet to encounter a transponder that has a direct static line connection. I suppose there is one out there that does, but I've yet to install or remove one.

 

[WannFly]

Thanks all, i will have to dig deeper into this. i know i have a blind encoder, but i do not know how its hooked up. if it makes any difference, my current transponder if SL-70, there is no place on the stack to mount a 345 that i was more interested in.. but will have to go with the R..pay same price, get less out of it .. grrr

 

[Bell206]

I've yet to encounter a transponder that has a direct static line connection.

FYI: Several compact xspndrs have built in encoders which requires direct static connection. Trig makes a good one.

 

[Ryan Klems]

FYI: Several compact xspndrs have built in encoders which requires direct static connection. Trig makes a good one.

Good to know. I still find the statement odd (Garmin's marketing statement around it), esp since the GAE only works with Garmin transponders (none of which have a direct connection).

 

[NordicDave]

Price it out parts and labor. Near zero labor for the GAE12. The cost of wiring up by trusty ACK encoder was $25 cheaper than buying the new Garmin encoder installed. Easy decision to pony up the extra $25 for the new nigher resolution Garmin.

 

[bnt83]

Where exactly are you mounting the remote transponder and is there a static port near it?

If you are gonna end up running a 10+ foot static line to the Garmin encoder, forget it, just get a brand new Trans Cal RS232 encoder and run WIRES to the transponder.

 

[Chip Sylverne]

Are you going to need to send RS232 encoder data to other equipment? The trans-Cal ssd120 has a couple rs232 output ports. Might be easier than paralleling off Garmin data port.

 

[asicer]

Easy decision to pony up the extra $25 for the new nigher resolution Garmin.

What benefit do you get from a higher resolution encoder?

 

[WannFly]

Where exactly are you mounting the remote transponder and is there a static port near it?

If you are gonna end up running a 10+ foot static line to the Garmin encoder, forget it, just get a brand new Trans Cal RS232 encoder and run WIRES to the transponder.

The transponder will be mounted in the tail where GDL 90 is right now, the static port in my archer is also in the far end of the tail cone

 

[WannFly]

Are you going to need to send RS232 encoder data to other equipment? The trans-Cal ssd120 has a couple rs232 output ports. Might be easier than paralleling off Garmin data port.

I will connect to GMX 200, I believe it’s over 232 but I may be wrong. You bring on a very valid point, down the road I might want to connect it to my gps as well and I believe that’s going to be a problem with one port

 

[WannFly]

so i spoke to my avoinic guy and he said he will just use G5 as the altitude source for the transponder and 345 will also get the OAT data to calculate DA from G5. on a different note, they might be able to get the panel mount unit and not worry about Remote unit.

there is a long pizzing match on mooneyspace about the legality of G5 as altitude source and some header in Beechtalk says yes you can use it .... that i am not getting into

 

[GeorgeC]

Different strokes for different folks, but I wouldn't want something upstream of my transponder... Why not drive the G5 off the 345?

 

[WannFly]

Different strokes for different folks, but I wouldn't want something upstream of my transponder... Why not drive the G5 off the 345?

from what i understand, the G5 is acting as the altitude source, not the other way around, i dont know if 345 can be a altitude source without the encoder. getting the source from G5 also allows baro corrected altitude. or so i have been told.

 

[asicer]

Different strokes for different folks, but I wouldn't want something upstream of my transponder... Why not drive the G5 off the 345?

G5 needs pitot-static for an AHRS solution. Feeding encoder altitude to the G5 would be redundant.

 

[Ryan Klems]

so i spoke to my avoinic guy and he said he will just use G5 as the altitude source for the transponder and 345 will also get the OAT data to calculate DA from G5. on a different note, they might be able to get the panel mount unit and not worry about Remote unit.

there is a long pizzing match on mooneyspace about the legality of G5 as altitude source and some header in Beechtalk says yes you can use it .... that i am not getting into

Not sure why folks would be arguing about that... the GTX 3XX installation manual as of R11 (R14 current) specifically allows feeding the airdata from a G5 + GAD 29/29B for altitude source.

 

[WannFly]

Not sure why folks would be arguing about that... the GTX 3XX installation manual as of R11 (R14 current) specifically allows feeding the airdata from a G5 + GAD 29/29B for altitude source.

I believe it’s because the install manual doesn’t specifically calls out that G5 can be used as a valid source in 345 and those pizzing matches are a kinda old, so may be it wasn’t a wide spread knowledge. Heck I had no idea, but that’s just normal...

 

[azure]

Kate is in the shop getting GTX 345 R... i am wondering if there is any benefit of installing Garmin altitude encoder? the avionics guy sayz no but... trust but verify ... what does POA say?

on a related note @azure is everything working for you with GMX 200 + 345R set up?

Negative. Still no ADS-B weather. Still trying to get back into the shop to have it fixed. (Otherwise, everything is working fine.)

 

[WannFly]

so the set up is done, i am yet to fly though. 345 is receiving OAT data from G5 and calculating DA just fine. pretty cool. on a similar note, G5 now shows DA on the screen as well, i believe it will only show DA on the ground as per garmin docs.

for people who are going the OAT probe route with G5 and wondering if you need another probe for 345 or not.. here is your answer

 

[WannFly]

@azure i did a test flight yesterday and i can confirm WX will show in GMX 200. so hoping in your case its just a config/ wiring issue. now the funny part is my traffic is not showing in GMX and i am hoping thats a config issue too

 

[azure]

@azure i did a test flight yesterday and i can confirm WX will show in GMX 200. so hoping in your case its just a config/ wiring issue. now the funny part is my traffic is not showing in GMX and i am hoping thats a config issue too

Thanks. I'm about 99.9% sure that it is a config issue. I don't think it can be a wiring issue since traffic data is being received and displayed by the unit, and I believe traffic and wx come over the same line. Your traffic issue probably is as well, and for the same reason.

However, getting the plane to the shop to be reconfigured is going to be hard now, since teaching online is far more time consuming than in-person, and that's going to continue at least through next month.

 

[WannFly]

Thanks. I'm about 99.9% sure that it is a config issue. I don't think it can be a wiring issue since traffic data is being received and displayed by the unit, and I believe traffic and wx come over the same line. Your traffic issue probably is as well, and for the same reason.

However, getting the plane to the shop to be reconfigured is going to be hard now, since teaching online is far more time consuming than in-person, and that's going to continue at least through next month.

once they get things working, i will send you some screenshots of the config to compare notes

 

[azure]

once they get things working, i will send you some screenshots of the config to compare notes

Cool, I'll do the same - but it won't be for a while, as I said.

 

[azure]

@azure i did a test flight yesterday and i can confirm WX will show in GMX 200. so hoping in your case its just a config/ wiring issue. now the funny part is my traffic is not showing in GMX and i am hoping thats a config issue too

The avionics shop finally resolved the ADS-B wx issue yesterday, by doing something I'm amazed they hadn't done a long time ago: disabling the GDL-69 that I had been getting my XM weather from. They told me it was intentional, in case I wanted both (or wanted to listen to XM radio ), but I'm pretty certain that my avionics guy back in Michigan told me that it was one or the other, you can't have both, and that it isn't a user-configurable option to switch between them.

Now my only issue is that the radar isn't overlaying on the MAP page, but that may just be an option that I can set, and if not, no biggie and not a reason to go back to XM. I'm going to see if I can get that working today. (I did notice, though, that METARS on the Text page were not consistently being displayed, and some stations' METARs would appear and disappear randomly.)

Did you ever get your traffic display fixed?

 

[WannFly]

The avionics shop finally resolved the ADS-B wx issue yesterday, by doing something I'm amazed they hadn't done a long time ago: disabling the GDL-69 that I had been getting my XM weather from. They told me it was intentional, in case I wanted both (or wanted to listen to XM radio ), but I'm pretty certain that my avionics guy back in Michigan told me that it was one or the other, you can't have both, and that it isn't a user-configurable option to switch between them.

Now my only issue is that the radar isn't overlaying on the MAP page, but that may just be an option that I can set, and if not, no biggie and not a reason to go back to XM. I'm going to see if I can get that working today. (I did notice, though, that METARS on the Text page were not consistently being displayed, and some stations' METARs would appear and disappear randomly.)

Did you ever get your traffic display fixed?

Good you got it fixed. I believe i was able to see the radar image on the default map page, but dont recall now. yes, it was a mis-configuration, traffic displayed just fine once they did the right configuration. none of that actually matters now since i took the dump (financial) decision to yank both the 480 + GMX 200 and replace it with GTN 750 Xi

 

[azure]

Good you got it fixed. I believe i was able to see the radar image on the default map page, but dont recall now. yes, it was a mis-configuration, traffic displayed just fine once they did the right configuration. none of that actually matters now since i took the dump (financial) decision to yank both the 480 + GMX 200 and replace it with GTN 750 Xi

I've been toying with a move like that myself. Today for the first time since the GTX-345 was installed, my GMX-200 crashed - on landing back at home base. Approach and landing were always phases of flight where it was more likely than usual to crash, but it hadn't done it EVEN ONCE during the time I had no weather data being received. I can't believe that's coincidental. I'm going to ask them if there is a way I can disable the FIS-B uplink to test this theory. The other factor has always been ambient temperature, and it was slightly warmer today than yesterday. If it is always going to crash when wx data is being received, I'll probably just disable wx entirely on the GMX-200 and go with a Stratus/iPad solution for wx.

But I have to admit, upgrading the GPS is very tempting...

 

[WannFly]

I've been toying with a move like that myself. Today for the first time since the GTX-345 was installed, my GMX-200 crashed - on landing back at home base. Approach and landing were always phases of flight where it was more likely than usual to crash, but it hadn't done it EVEN ONCE during the time I had no weather data being received. I can't believe that's coincidental. I'm going to ask them if there is a way I can disable the FIS-B uplink to test this theory. The other factor has always been ambient temperature, and it was slightly warmer today than yesterday. If it is always going to crash when wx data is being received, I'll probably just disable wx entirely on the GMX-200 and go with a Stratus/iPad solution for wx.

But I have to admit, upgrading the GPS is very tempting...

interesting. i cant see why the GMX will crash with the WX data from GTX... mine was connected to GDL 90 for both WX and FIS-B, never crashed and i have operated in pretty extreme weather (both positive and negative )

 

[jbrrapa]

...my avionics guy back in Michigan told me that it was one or the other, you can't have both, and that it isn't a user-configurable option to switch between them

That is not accurate. I have a GTX345 and a GDL69. I receive both XM weather and ADS B weather on my GNS 530W and my GNS430W. There is a separate screen for each.

 

[WannFly]

That is not accurate. I have a GTX345 and a GDL69. I receive both XM weather and ADS B weather on my GNS 530W and my GNS430W. There is a separate screen for each.

may not be true for GMX 200. Per the manual:



so that explains why @azure wasnt seeing WX from 345

 

[azure]

That is not accurate. I have a GTX345 and a GDL69. I receive both XM weather and ADS B weather on my GNS 530W and my GNS430W. There is a separate screen for each.

I can't speak to that. I'm talking about a GMX-200, different hardware entirely.

 

[azure]

interesting. i cant see why the GMX will crash with the WX data from GTX... mine was connected to GDL 90 for both WX and FIS-B, never crashed and i have operated in pretty extreme weather (both positive and negative )

Yes, there is clearly something strange with my installation. But it doesn't appear to be internal to the GMX-200 as the unit was out to Garmin last fall (to the tune of 1 AMU) and was returned without anything done - Garmin couldn't reproduce the problem.

There was a known issue with wx data swamping the GMX-200 under an earlier software revision and causing the unit to crash. But my software for the unit is up to date and has been for a couple of years... and it still happens.

Extreme weather doesn't seem to have anything to do with it either... it is just (apparently) the fact that the uplink (or the GDL-69) is sending it wx.

Now I might have to eat my words if disabling wx in the summer heat does nothing to stop the crashes... then the solution might be to install some extra cooling fans behind the panel.

 

[N41457]

so the set up is done, i am yet to fly though. 345 is receiving OAT data from G5 and calculating DA just fine. pretty cool. on a similar note, G5 now shows DA on the screen as well, i believe it will only show DA on the ground as per garmin docs.

for people who are going the OAT probe route with G5 and wondering if you need another probe for 345 or not.. here is your answer

We just had the davtron probe we used for temp on our 345 reconfigured to work with our G5 (through a GAD-13). Wind barb, TAS and temp all appear on G5, but how do we get the data back to the GTX-345?

 

[Ryan Klems]

We just had the davtron probe we used for temp on our 345 reconfigured to work with our G5 (through a GAD-13). Wind barb, TAS and temp all appear on G5, but how do we get the data back to the GTX-345?

If you have the latest firmware installed, and an ARINC 429 feed from your GAD29(B) to the GTX-345 and configured properly ok both sides, it should be transmitting all the air data to the 345.