Results 1 to 28 of 28

Thread: mag static in headsets

  1. #1

    Join Date
    Jul 2007
    Posts
    222
    Post Thanks / Like

    mag static in headsets

    I am getting static in my headset that I believe is coming through the Mag's. As RPM increases the static frequency increases as well. My Mag switch is located within 4 inches for the headset jacks could this be causing the problem? Any suggestions would help. Before anyone asks, no I did not shut the mag switch off in flight to see if it made it stop (then I would have to change the seat cover)

  2. #2

    Join Date
    Nov 2012
    Location
    Lake Lanier, GA
    Posts
    1,072
    Post Thanks / Like
    Sometimes it can be mag but try this. Clean your battery ground first, both ends. Then try turning off your alternator in flight to see if it might be a bad diode.

  3. #3
    wireweinie's Avatar
    Join Date
    Aug 2013
    Location
    Palmer, AK
    Posts
    2,561
    Post Thanks / Like
    No need for plastic seat covers!

    Do you get the noise on the ground and in the air, both? Does it change when you do a mag drop test? Have you turned off the alternator/regulator when you hear the noise? Does that change it? Has it always done this or did it just start?

    Web
    Life's tough . . . wear a cup.
    Likes mike mcs repair liked this post

  4. #4

    Join Date
    Apr 2018
    Location
    Knoxville, Tn.
    Posts
    174
    Post Thanks / Like
    Does it come in through both headset jacks? Does it happen with two different headsets through the same jack?
    Likes mike mcs repair liked this post

  5. #5

    Join Date
    Jul 2007
    Posts
    222
    Post Thanks / Like
    Noise occurs in all situations with engine running, no alternator on aircraft ( using small rechargeable battery). Noise reduces small amount on single mag, as always done it, noise comes through both headsets, have tried alternate headsets.

  6. #6
    wireweinie's Avatar
    Join Date
    Aug 2013
    Location
    Palmer, AK
    Posts
    2,561
    Post Thanks / Like
    Make sure no wires are bundled with your p-leads. Also, use shielded wire for the p-leads. Tie one end of the shield to the mag body and the other end of the shield to the ground tab on your switch. This will keep the electrical noise out of the airframe. Then make sure that you have isolation washers on your mic/phone jacks.

    Web
    Life's tough . . . wear a cup.
    Likes mike mcs repair liked this post

  7. #7

    Join Date
    Jul 2007
    Posts
    222
    Post Thanks / Like
    Thanks I’ll see if that works

  8. #8

    Join Date
    Apr 2018
    Location
    Knoxville, Tn.
    Posts
    174
    Post Thanks / Like
    I like wirewienie's idea that you may not have isolation washers on your mic and phone jacks.

    If your frame has ever been sand blasted and epoxy coated, make sure that the ground lead going straight from the battery is attached to a point on the frame where the epoxy has been sanded or wire-brushed off.

    Do you have ANR headsets? If so do you get the static with the ANR off?

    Does the static happen with the intercom off?
    Likes mike mcs repair liked this post

  9. #9

    Join Date
    Dec 2014
    Location
    Nikiski
    Posts
    6
    Post Thanks / Like
    I had intermittent static problems with my KX155 and after exhaustive trouble shooting/trial and error turned out to be caused by the USB cigarette lighter charger when charging either my I-phone or I-pad. Not all frequencies were effected consistently and the radio seemed to transmit clearly all the time.

    I even took the radio to an avionics shop in Kenai (but I will not mention their name) and they luckily didn't have time to work on it as their estimate for fixing was cheaper to replace it than fix it.
    Likes cubpilot2 liked this post

  10. #10

    Join Date
    Jan 2013
    Posts
    8
    Post Thanks / Like
    I isolated jacks and cked p-leads. No change in the mag noise. I did a continuity ck on the jacks and every part of the jack is grounded to the airframe. Unplugged radio harness (flight line 760) tall post on the jack is isolated. Cked pin on the radio #14 headphone output and that is grounded to the radio case, thus grounding the jacks. This doesn’t seem correct. Calling flightline this week. Decided to go fishing and think. Thanks CuBob for connecting me up with SC.org.

  11. #11
    wireweinie's Avatar
    Join Date
    Aug 2013
    Location
    Palmer, AK
    Posts
    2,561
    Post Thanks / Like
    Unplug all headphones/mics/music. The ONLY part of ANY jack that should read directly to ground is the threaded part with the nut on it.

    Is this an ongoing problem or has it just started?

    Web
    Life's tough . . . wear a cup.

  12. #12
    www.SkupTech.com mike mcs repair's Avatar
    Join Date
    Aug 2004
    Location
    chugiak AK
    Posts
    10,478
    Post Thanks / Like
    Quote Originally Posted by keeger View Post
    I isolated jacks and cked p-leads. No change in the mag noise. I did a continuity ck on the jacks and every part of the jack is grounded to the airframe. Unplugged radio harness (flight line 760) tall post on the jack is isolated. Cked pin on the radio #14 headphone output and that is grounded to the radio case, thus grounding the jacks. This doesn’t seem correct. Calling flightline this week. Decided to go fishing and think. Thanks CuBob for connecting me up with SC.org.
    No, ISOLATE FROM AIRFAME. ONLY GROUND AT RADIO


    Sent from my iPhone using SuperCub.Org mobile app

  13. #13

    Join Date
    Jan 2007
    Posts
    1,707
    Post Thanks / Like
    Do you have the plastic washer with the collar on them to isolate the jack from whatever it is mounted in?

    https://www.steinair.com/product/fiber-washers/

    DENNY
    Likes mike mcs repair liked this post

  14. #14

    Join Date
    Jan 2013
    Posts
    8
    Post Thanks / Like
    New radio, purchased 2 Year’s ago. Flew cub first time last fall. Experimental. On going problem from the start. Airframe is grounded to the battery. Radio grounded to the battery neg. buss.

  15. #15

    Join Date
    Jan 2013
    Posts
    8
    Post Thanks / Like
    Yep, fiber collar on the inside Thur panel, flat fiber on outside under nut and washer

  16. #16
    wireweinie's Avatar
    Join Date
    Aug 2013
    Location
    Palmer, AK
    Posts
    2,561
    Post Thanks / Like
    Shielded wire on the P-leads? How are the P-leads connected/routed? Bundled with any other wires?

    Web
    Life's tough . . . wear a cup.
    Likes mike mcs repair liked this post

  17. #17

    Join Date
    Jan 2013
    Posts
    8
    Post Thanks / Like
    Shielded wire on leads, routed with no other wires. Connected shield to mag grd screw and to grd terminal on mag switch. No other grds connected. Slick mags are new. 32 hrs on exp. cub

  18. #18
    wireweinie's Avatar
    Join Date
    Aug 2013
    Location
    Palmer, AK
    Posts
    2,561
    Post Thanks / Like
    How about the radio wiring? Shielded wires on the phones and mic leads?

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

  19. #19

    Join Date
    Jan 2013
    Posts
    8
    Post Thanks / Like
    Yea, I did use shield wires for phone and mic jacks, open on one end.. What baffles me is why the headphone pin on the radio is grounded internal in the radio. The harness cked out good one wire at a time. I do transmit and receive well, except for the noise.

  20. #20
    www.SkupTech.com mike mcs repair's Avatar
    Join Date
    Aug 2004
    Location
    chugiak AK
    Posts
    10,478
    Post Thanks / Like
    a bad spark plug lead on ignition harness???

  21. #21
    www.SkupTech.com mike mcs repair's Avatar
    Join Date
    Aug 2004
    Location
    chugiak AK
    Posts
    10,478
    Post Thanks / Like
    dismount jacks or mag switch and move them away from each other and test...???

  22. #22

    Join Date
    Jan 2005
    Location
    Fowler, Ks
    Posts
    525
    Post Thanks / Like
    engine ground good?
    Likes mike mcs repair liked this post

  23. #23
    www.SkupTech.com mike mcs repair's Avatar
    Join Date
    Aug 2004
    Location
    chugiak AK
    Posts
    10,478
    Post Thanks / Like
    Quote Originally Posted by flynlow View Post
    engine ground good?
    in theory it shouldn't mater IF mag switch wired/isolated as Web described, and no alternator/starter..

  24. #24

    Join Date
    Jan 2005
    Location
    Fowler, Ks
    Posts
    525
    Post Thanks / Like
    Yeah, if the p leads are making good connections....wouldn't take a minute with a wire and alligator clips to check?? plug wires? the little spring thingy in the spark plug wire end.?
    Likes mike mcs repair liked this post

  25. #25
    jimboflying's Avatar
    Join Date
    May 2005
    Posts
    502
    Post Thanks / Like
    I chased radio noise that only occurred on 122.8 for several years. It finally went away when i replaced 3 spark plugs. Stranger than fiction but it was true.
    Likes mike mcs repair liked this post

  26. #26

    Join Date
    Apr 2018
    Location
    Knoxville, Tn.
    Posts
    174
    Post Thanks / Like
    One last idea - can you hear the noise on a handheld when the engine is started? If so, that would help isolate the problem to the ignition wiring itself.
    Likes mike mcs repair liked this post

  27. #27

    Join Date
    Jan 2013
    Posts
    8
    Post Thanks / Like
    I did the hand held thing. Still had mag noise. One last try. When I built the airplane, I acquired some really cool wire loom. It looked like a rattle snake skin, nice shiny aluminum with fire resistant glass on the inside. I put my p- leads thur that on the firewall. A big giant antenna. It’s gone now and so is most the noise. Thanks for all the help. I know my electrical system better than ever. Keep the wheels pointed down.
    Likes mike mcs repair liked this post

  28. #28
    www.SkupTech.com mike mcs repair's Avatar
    Join Date
    Aug 2004
    Location
    chugiak AK
    Posts
    10,478
    Post Thanks / Like
    Quote Originally Posted by keeger View Post
    I did the hand held thing. Still had mag noise. .
    plugs or wires

Similar Threads

  1. ANR headsets (say again?)
    By NimpoCub in forum Cafe Supercub
    Replies: 22
    Last Post: 03-02-2013, 11:49 PM
  2. Headsets
    By 5191H in forum Products, Purchases, Reviews & Prices
    Replies: 12
    Last Post: 12-09-2010, 12:31 AM
  3. Which headsets?
    By CptKelly in forum Cafe Supercub
    Replies: 47
    Last Post: 12-13-2004, 05:51 PM

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
  •