Intermittent 430W com static

Discussion in 'Avionics and Upgrades' started by Jim Boyd, Aug 4, 2019.

  1. Jim Boyd

    Jim Boyd Filing Flight Plan

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    Back in 2012 I was having issues with com static on a 430W. After installing an alternator noise filter, replacing the ELT and adjusting the squelch on the 430 everything was great. Now, on the last 2 takeoffs the static is back BUT... it only lasts up to around 2,000 AGL then falls off. Climbing to 8,500 then is quiet, cruise is quiet. No power adjustments in the climb and minimal static, if any, in the descent except around 2,000 AGL then all quiet down to the pattern and landing. So it's mostly a full power thing but only up to around 2,000 AGL...hmmm...??? First guess is the noise filter is going bad? Any other thoughts?
     
  2. denverpilot

    denverpilot Taxi to Parking

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    Thoughts:

    Local interference on the ground or in the area. Is it on all frequencies?

    Something heating up and making better contact in your electrical system as it heats and expands under the coal.
     
  3. SkyDog58

    SkyDog58 Ejection Handle Pulled PoA Supporter

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    Is it just at a specific airport or anytime you are around 2000'?
     
  4. Jim Boyd

    Jim Boyd Filing Flight Plan

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    Well, all good questions. I haven't ventured to other airports so far but it is on all frequencies or at least 2-3 that I have flipped in to so far. The static intermittently starts at around 40-45 knots on the takeoff roll and becomes constant after takeoff. Remains constant until around 2,000 agl and then becomes intermittent and then clears by 2,500-3,000 agl. I make no change in power, pitch, etc... Lycoming O-360. My other radio is a King KX-165 and it remains static free...
     
  5. Hang 4

    Hang 4 Pre-takeoff checklist

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    Wild, fact free guess - is there an ILS?
     
  6. Jim Boyd

    Jim Boyd Filing Flight Plan

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    No, nothing but RNAV approaches...
     
  7. IK04

    IK04 Cleared for Takeoff

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    You might look into emergency or hospital services in the immediate area. I know of a particular area where the emergency comms center at a hospital causes interference to all radios in the vicinity...
     
  8. EdFred

    EdFred Touchdown! Greaser! PoA Supporter

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    Do you have any portable electronics turned on? I had a portable ADS-B receiver that would cause static on both the 430W and the SL40.
     
  9. Jim Boyd

    Jim Boyd Filing Flight Plan

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    The emergency/hospital post is interesting. There is a hospital just south of the airport so I'm wondering if they've put in new radios that's giving the Garmin fits. It's always been more sensitive - the KX165 has never given me any fits. No portable electronics on other than my cell phone but that's always been on and haven't had the issue until the last 2 flights 7 days apart. Thanks!
     
  10. Clip4

    Clip4 En-Route

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    Bad ground
     
  11. denverpilot

    denverpilot Taxi to Parking

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    Yeah this is the next thing I would try with it being on all frequencies. It’s more likely to be on board the aircraft with that piece of news.
     
  12. Jim Boyd

    Jim Boyd Filing Flight Plan

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    Thanks to all for your replies. One other simple option I want to check based on other posts is the USB charger in the cigarette lighter. If I leave it out and it clears then easy fix. Otherwise I'll run the alternator field test- thanks!