GTX 345 - with or without Garmin altitude encoder

Discussion in 'Avionics and Upgrades' started by WannFly, Mar 9, 2020.

  1. WannFly

    WannFly En-Route

    Joined:
    Nov 28, 2016
    Messages:
    4,758
    Location:
    KFAR
    Display Name:

    Display name:
    Priyo
    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
     
    Last edited: Mar 20, 2020
  2. asicer

    asicer En-Route

    Joined:
    Jan 1, 2015
    Messages:
    4,963
    Display Name:

    Display name:
    asicer
    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.
     
  3. GeorgeC

    GeorgeC En-Route

    Joined:
    Dec 5, 2010
    Messages:
    3,013
    Display Name:

    Display name:
    GeorgeC
    :yeahthat: 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.
     
    Last edited: Mar 9, 2020
  4. simtech

    simtech En-Route

    Joined:
    Aug 15, 2012
    Messages:
    2,738
    Location:
    mississippi
    Display Name:

    Display name:
    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.
     
  5. Ryan Klems

    Ryan Klems Pre-takeoff checklist

    Joined:
    May 21, 2018
    Messages:
    161
    Location:
    Tucson, AZ
    Display Name:

    Display name:
    Rowat
    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.
     
  6. WannFly

    WannFly En-Route

    Joined:
    Nov 28, 2016
    Messages:
    4,758
    Location:
    KFAR
    Display Name:

    Display name:
    Priyo
    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
     
  7. Bell206

    Bell206 En-Route

    Joined:
    Oct 6, 2017
    Messages:
    2,548
    Display Name:

    Display name:
    Bell206
    FYI: Several compact xspndrs have built in encoders which requires direct static connection. Trig makes a good one.
     
  8. Ryan Klems

    Ryan Klems Pre-takeoff checklist

    Joined:
    May 21, 2018
    Messages:
    161
    Location:
    Tucson, AZ
    Display Name:

    Display name:
    Rowat
    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).
     
  9. NordicDave

    NordicDave Cleared for Takeoff

    Joined:
    Oct 31, 2015
    Messages:
    1,364
    Location:
    San Jose
    Display Name:

    Display name:
    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.
     
    WannFly likes this.
  10. bnt83

    bnt83 Final Approach PoA Supporter

    Joined:
    Dec 31, 2012
    Messages:
    8,915
    Location:
    Lincoln NE
    Display Name:

    Display name:
    Brian
    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.
     
    WannFly likes this.
  11. Chip Sylverne

    Chip Sylverne En-Route

    Joined:
    Jun 17, 2006
    Messages:
    4,893
    Display Name:

    Display name:
    Fear is the poison of our lives.
    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.
     
  12. asicer

    asicer En-Route

    Joined:
    Jan 1, 2015
    Messages:
    4,963
    Display Name:

    Display name:
    asicer
    What benefit do you get from a higher resolution encoder?
     
  13. WannFly

    WannFly En-Route

    Joined:
    Nov 28, 2016
    Messages:
    4,758
    Location:
    KFAR
    Display Name:

    Display name:
    Priyo
    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
     
  14. WannFly

    WannFly En-Route

    Joined:
    Nov 28, 2016
    Messages:
    4,758
    Location:
    KFAR
    Display Name:

    Display name:
    Priyo
    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
     
  15. WannFly

    WannFly En-Route

    Joined:
    Nov 28, 2016
    Messages:
    4,758
    Location:
    KFAR
    Display Name:

    Display name:
    Priyo
    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
     
  16. GeorgeC

    GeorgeC En-Route

    Joined:
    Dec 5, 2010
    Messages:
    3,013
    Display Name:

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

    WannFly En-Route

    Joined:
    Nov 28, 2016
    Messages:
    4,758
    Location:
    KFAR
    Display Name:

    Display name:
    Priyo
    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.
     
  18. asicer

    asicer En-Route

    Joined:
    Jan 1, 2015
    Messages:
    4,963
    Display Name:

    Display name:
    asicer
    G5 needs pitot-static for an AHRS solution. Feeding encoder altitude to the G5 would be redundant.
     
    WannFly and GeorgeC like this.
  19. Ryan Klems

    Ryan Klems Pre-takeoff checklist

    Joined:
    May 21, 2018
    Messages:
    161
    Location:
    Tucson, AZ
    Display Name:

    Display name:
    Rowat
    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.
     
  20. WannFly

    WannFly En-Route

    Joined:
    Nov 28, 2016
    Messages:
    4,758
    Location:
    KFAR
    Display Name:

    Display name:
    Priyo
    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...
     
  21. azure

    azure Final Approach

    Joined:
    Apr 2, 2005
    Messages:
    8,233
    Location:
    Varmint Country
    Display Name:

    Display name:
    azure
    Negative. Still no ADS-B weather. Still trying to get back into the shop to have it fixed. (Otherwise, everything is working fine.)
     
    WannFly likes this.
  22. WannFly

    WannFly En-Route

    Joined:
    Nov 28, 2016
    Messages:
    4,758
    Location:
    KFAR
    Display Name:

    Display name:
    Priyo
    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
     
  23. WannFly

    WannFly En-Route

    Joined:
    Nov 28, 2016
    Messages:
    4,758
    Location:
    KFAR
    Display Name:

    Display name:
    Priyo
    @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 :p
     
  24. azure

    azure Final Approach

    Joined:
    Apr 2, 2005
    Messages:
    8,233
    Location:
    Varmint Country
    Display Name:

    Display name:
    azure
    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.
     
  25. WannFly

    WannFly En-Route

    Joined:
    Nov 28, 2016
    Messages:
    4,758
    Location:
    KFAR
    Display Name:

    Display name:
    Priyo
    once they get things working, i will send you some screenshots of the config to compare notes
     
    azure likes this.
  26. azure

    azure Final Approach

    Joined:
    Apr 2, 2005
    Messages:
    8,233
    Location:
    Varmint Country
    Display Name:

    Display name:
    azure
    Cool, I'll do the same - but it won't be for a while, as I said.
     
    WannFly likes this.