AeroElectric-List Digest Archive

Fri 02/21/14


Total Messages Posted: 6



Today's Message Index:
----------------------
 
     1. 05:52 AM - Re: noise problem on radio - seems to be correlated to Autopilot being ON and Engine RPM (Robert L. Nuckolls, III)
     2. 06:48 AM - Re: noise problem on radio (Robert L. Nuckolls, III)
     3. 06:49 AM - Off line for a few days . . . (Robert L. Nuckolls, III)
     4. 07:18 AM - Rotax 91X 26 amp Gen2 $137.50 per amp (rparigoris)
     5. 07:20 AM - Rotax 91X 26 amp Gen2 $137.50 per amp (rparigoris)
     6. 08:07 AM - Re: Off line for a few days . . . (Roger & Jean)
 
 
 


Message 1


  • INDEX
  • Back to Main INDEX
  • NEXT
  • Skip to NEXT Message
  • LIST
  • Reply to LIST Regarding this Message
  • SENDER
  • Reply to SENDER Regarding this Message
    Time: 05:52:52 AM PST US
    From: "Robert L. Nuckolls, III" <nuckolls.bob@aeroelectric.com>
    Subject: Re: noise problem on radio - seems to be correlated
    to Autopilot being ON and Engine RPM The noise is intermittent but seems to be strongly correlated to two things - when the Autopilot (Trio Avionics ProPilot) is switched on I get much more noise. This noise is present even when the engine is off. It's like the squelch breaking. The image (or sound) that pops to mind with the term "squelch breaking" is the sort of white noise you get from an receiver when no useful signal is present but the volume is turned up. The noise is a combination of atmospheric and internally generated noises. Is this the kind of noise you're hearing? For some reason I've noticed that it happens more when I move the stick back and forth... I have no idea why this may be. - engine RPM - when I increase the throttle the noise becomes more and seems to increase in pitch and intensity. But it's present even when the engine is not running? I'm suspecting at least one faulty ground connection. Not sure there is foundation for this supposition yet . . . It's possible that it could also be due to the fact that the magneto wires (well, I'm not sure they are real magnetos, the engine is a Rotax 912UL) are not shielded as I didn't know any better when I wired them the first time. The 912 has a form of capacitor discharge ignition system. See . . . http://tinyurl.com/mmwemuu The capacitors are charged via separate coils on the PM alternator stator stack . . . the larger two of ten coils visible here. http://tinyurl.com/lndjw9n The Rotax manual calls for shielded wire on the ignition control lines . . . which is fine . . . but it also calls for the shields to be grounded at both ends which is not fine . . . at the engine end only and use the shield as a ground for the ignition switch. See: http://tinyurl.com/n3oy37f However, since you say the noise is present with the engine not running . . . then the wiring of the ignition switches is not a likely source of your difficulties. (Most of the wires that come from the panel go through connectors; in this way, I can remove the panel from the aircraft by detaching three connectors and the wire harness to the Autopilot.). My question is: how do I go about isolating what the fault might be? I'm dreading having to take apart every single wire in the avionics interconnections. Study the chapter on noise and formulate a plan . . . it's like playing Clue (Mr. Mustard with the Pipe in the Library). This is an exercise in hypothesis development and elimination which starts with identifying the antagonist. The antagonist's nose signature is your first clue . . . so we first need to qualify the "breaking squelch" term. Bob . . .


    Message 2


  • INDEX
  • Back to Main INDEX
  • PREVIOUS
  • Skip to PREVIOUS Message
  • NEXT
  • Skip to NEXT Message
  • LIST
  • Reply to LIST Regarding this Message
  • SENDER
  • Reply to SENDER Regarding this Message
    Time: 06:48:16 AM PST US
    From: "Robert L. Nuckolls, III" <nuckolls.bob@aeroelectric.com>
    Subject: Re: noise problem on radio
    URL Corrections. Seems my capture of image URLs out on the web were flaky . . . I've posted the images to my website and re-linked them in this repeat of my earlier posting . . . =============================================================== <nuckolls.bob@aeroelectric.com> The noise is intermittent but seems to be strongly correlated to two things - when the Autopilot (Trio Avionics ProPilot) is switched on I get much more noise. This noise is present even when the engine is off. It's like the squelch breaking. The image (or sound) that pops to mind with the term "squelch breaking" is the sort of white noise you get from an receiver when no useful signal is present but the volume is turned up. The noise is a combination of atmospheric and internally generated noises. Is this the kind of noise you're hearing? For some reason I've noticed that it happens more when I move the stick back and forth... I have no idea why this may be. - engine RPM - when I increase the throttle the noise becomes more and seems to increase in pitch and intensity. But it's present even when the engine is not running? I'm suspecting at least one faulty ground connection. Not sure there is foundation for this supposition yet . . . It's possible that it could also be due to the fact that the magneto wires (well, I'm not sure they are real magnetos, the engine is a Rotax 912UL) are not shielded as I didn't know any better when I wired them the first time. The 912 has a form of capacitor discharge ignition system. See . . . http://tinyurl.com/ouvxh42 The capacitors are charged via separate coils on the PM alternator stator stack . . . the larger two of ten coils visible here. http://tinyurl.com/ohkdgc6 The Rotax manual calls for shielded wire on the ignition control lines . . . which is fine . . . but it also calls for the shields to be grounded at both ends which is not fine . . . at the engine end only and use the shield as a ground for the ignition switch. See: http://tinyurl.com/n3oy37f However, since you say the noise is present with the engine not running . . . then the wiring of the ignition switches is not a likely source of your difficulties. (Most of the wires that come from the panel go through connectors; in this way, I can remove the panel from the aircraft by detaching three connectors and the wire harness to the Autopilot.). My question is: how do I go about isolating what the fault might be? I'm dreading having to take apart every single wire in the avionics interconnections. Study the chapter on noise and formulate a plan . . . it's like playing Clue (Mr. Mustard with the Pipe in the Library). This is an exercise in hypothesis development and elimination which starts with identifying the antagonist. The antagonist's nose signature is your first clue . . . so we first need to qualify the "breaking squelch" term. Bob . . .


    Message 3


  • INDEX
  • Back to Main INDEX
  • PREVIOUS
  • Skip to PREVIOUS Message
  • NEXT
  • Skip to NEXT Message
  • LIST
  • Reply to LIST Regarding this Message
  • SENDER
  • Reply to SENDER Regarding this Message
    Time: 06:49:30 AM PST US
    From: "Robert L. Nuckolls, III" <nuckolls.bob@aeroelectric.com>
    Subject: Off line for a few days . . .
    Dr. Dee and I are going to pick up her favorite aunt and uncle in Leon, KS today and meander up through the Flint Hills toward Kansas City for an 'unplugged' weekend . . . Be back Monday night . . . Bob . . .


    Message 4


  • INDEX
  • Back to Main INDEX
  • PREVIOUS
  • Skip to PREVIOUS Message
  • NEXT
  • Skip to NEXT Message
  • LIST
  • Reply to LIST Regarding this Message
  • SENDER
  • Reply to SENDER Regarding this Message
    Time: 07:18:45 AM PST US
    Subject: Rotax 91X 26 amp Gen2 $137.50 per amp
    From: "rparigoris" <rparigor@suffolk.lib.ny.us>
    Hi Group Those who have a Rotax 91X know things aren't cheap. Here's a 26 amp Gen2 for $137.50 per amp: http://sportair.aero/12-epapower/epapower/ Ron Parigoris BTW if you are a real die hard you can put one on the 130 HP 915 for $57,250 Read this topic online here: http://forums.matronics.com/viewtopic.php?p=419115#419115


    Message 5


  • INDEX
  • Back to Main INDEX
  • PREVIOUS
  • Skip to PREVIOUS Message
  • NEXT
  • Skip to NEXT Message
  • LIST
  • Reply to LIST Regarding this Message
  • SENDER
  • Reply to SENDER Regarding this Message
    Time: 07:20:28 AM PST US
    Subject: Rotax 91X 26 amp Gen2 $137.50 per amp
    From: "rparigoris" <rparigor@suffolk.lib.ny.us>
    Hi Group Those who have a Rotax 91X know things aren't cheap. Here's a 26 amp Gen2 for $137.50 per amp: http://sportair.aero/12-epapower/epapower/ Ron Parigoris BTW if you are a real die hard you can put one on the 130 HP 915 for $57,250 Read this topic online here: http://forums.matronics.com/viewtopic.php?p=419117#419117


    Message 6


  • INDEX
  • Back to Main INDEX
  • PREVIOUS
  • Skip to PREVIOUS Message
  • NEXT
  • Skip to NEXT Message
  • LIST
  • Reply to LIST Regarding this Message
  • SENDER
  • Reply to SENDER Regarding this Message
    Time: 08:07:04 AM PST US
    From: "Roger & Jean" <mrspudandcompany@verizon.net>
    Subject: Re: Off line for a few days . . .
    > Dr. Dee and I are going to pick up her favorite > aunt and uncle in Leon, KS today and meander up > through the Flint Hills toward Kansas City for > an 'unplugged' weekend . . . > > Be back Monday night . . . > > > Bob . . . Have a great weekend!!!! ? Roger --- This email is free from viruses and malware because avast! Antivirus protection is active. http://www.avast.com




    Other Matronics Email List Services

  • Post A New Message
  •   aeroelectric-list@matronics.com
  • UN/SUBSCRIBE
  •   http://www.matronics.com/subscription
  • List FAQ
  •   http://www.matronics.com/FAQ/AeroElectric-List.htm
  • Web Forum Interface To Lists
  •   http://forums.matronics.com
  • Matronics List Wiki
  •   http://wiki.matronics.com
  • 7-Day List Browse
  •   http://www.matronics.com/browse/aeroelectric-list
  • Browse AeroElectric-List Digests
  •   http://www.matronics.com/digest/aeroelectric-list
  • Browse Other Lists
  •   http://www.matronics.com/browse
  • Live Online Chat!
  •   http://www.matronics.com/chat
  • Archive Downloading
  •   http://www.matronics.com/archives
  • Photo Share
  •   http://www.matronics.com/photoshare
  • Other Email Lists
  •   http://www.matronics.com/emaillists
  • Contributions
  •   http://www.matronics.com/contribution

    These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.

    -- Please support this service by making your Contribution today! --