Results 1 to 9 of 9

Thread: Transponder encoder issues

  1. #1
    jimboflying's Avatar
    Join Date
    May 2005
    Posts
    454
    Post Thanks / Like

    Transponder encoder issues

    ATC says that my reported altitude can jump 800-1000 feet without me changing altitude. What are the likely problem areas to look at?

  2. #2
    mvivion's Avatar
    Join Date
    Jun 2003
    Location
    Bozeman,MT
    Posts
    9,852
    Post Thanks / Like
    Quote Originally Posted by jimboflying View Post
    ATC says that my reported altitude can jump 800-1000 feet without me changing altitude. What are the likely problem areas to look at?
    Jim,

    Must be those new Keller flaps......sorry, couldn’t resist.

    Back to your normal broadcast.

    MTV
    Likes kestrel liked this post

  3. #3
    www.SkupTech.com mike mcs repair's Avatar
    Join Date
    Aug 2004
    Location
    chugiak AK
    Posts
    9,185
    Post Thanks / Like
    it's just measuring static pressure, where is your static sourced from?

  4. #4
    TirolCub's Avatar
    Join Date
    Sep 2006
    Location
    Austria
    Posts
    192
    Post Thanks / Like
    ... maybe your Altitude Encoder needs adjustment ? If it is an ACK01 it is simple, but you need an Avionics guy with the equipment. Hope that helps ...

  5. #5

    Join Date
    Sep 2003
    Posts
    6,051
    Post Thanks / Like
    Mine just quit. I "re-racked" the transponder, and re- secured the encoder to its mount, and back to normal. Only a year and a half, and those two things will be worthless!

  6. #6

    Join Date
    Oct 2012
    Posts
    3,389
    Post Thanks / Like
    Mine's gone wonky a couple of times through the years. I just have the avionics shop adjust and recertify it. Lake Hood airspace is sensitive to altitude so when the encoder is mis-reporting tower questions it. I just turn mode C off until I get it fixed.

  7. #7
    wireweinie's Avatar
    Join Date
    Aug 2013
    Location
    Palmer, AK
    Posts
    1,741
    Post Thanks / Like
    Check the basics. Wire connector secure on encoder. Re rack the transponder. Check for loose wire connections at the back of the transponder. Check for leaks in the static lines. If there is still no improvement, have the encoder bench checked. It is most likely going to be an encoder issue, not transponder, as altitude is the only issue you report.

    Web
    Life's tough . . . wear a cup.
    Thanks jimboflying thanked for this post

  8. #8
    hotrod180's Avatar
    Join Date
    May 2008
    Location
    Port Townsend, WA
    Posts
    1,949
    Post Thanks / Like
    Quote Originally Posted by bob turner View Post
    Mine just quit. I "re-racked" the transponder, and re- secured the encoder to its mount, and back to normal. Only a year and a half, and those two things will be worthless!
    I disagree.
    If you need a transponder & encoder where you fly, then you'll still need them in 2020.
    You will also need an ADS-B out system, in addition to the transponder.
    Some ADS-B systems incorporate a txp to replace your existing set-up, some are in addition to it.
    I will likely keep my "legacy" mode C txp, and add something like the Garmin GDL82.
    Cessna Skywagon-- accept no substitute!
    Likes kestrel liked this post

  9. #9
    Colorguns's Avatar
    Join Date
    Dec 2013
    Location
    Bloomfield NY
    Posts
    253
    Post Thanks / Like
    Local shop had some issues with an old encoder after an install, Now they install a new encoder as part of the install as standard procedure. The encoder was giving hem issues.


    Might be the real issue?

    Doug

Similar Threads

  1. Replies: 3
    Last Post: 02-01-2018, 10:40 AM
  2. Altitude encoder allowable deviation?
    By StewartB in forum Super Cub Sick Bay
    Replies: 6
    Last Post: 04-29-2011, 05:39 PM
  3. Transponder DOA
    By OLDCROWE in forum Super Cub Sick Bay
    Replies: 5
    Last Post: 08-15-2008, 02:38 PM
  4. Com/transponder/encoder in non-electric airplane
    By d.grimm in forum Modifications
    Replies: 7
    Last Post: 05-10-2006, 06:37 AM

Bookmarks

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •