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Showerthought: I swapped from generic to proper shielded cable for a GPS antenna run and the noise floor dropped like a rock.

Had a persistent intermittent fault on a Garmin GTN 750 install in a Cessna 182. The GPS signal kept dropping. I first used a standard unshielded Tefzel wire for the antenna run, thinking it was fine for the short distance. After re-running it with a proper RG-400 coaxial cable, the signal stabilized completely. The shielding made all the difference in blocking interference from the aircraft's other systems. Has anyone else had a similar fix with antenna wiring?
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3 Comments
angelar57
angelar571mo ago
Wow, same thing happened when I finally swapped to shielded wire.
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kim_west
kim_west1mo ago
My buddy Jake had a GPS issue in his old Mooney that drove him nuts for a month. He kept getting random signal losses on approach. He checked every connector twice. Finally, on a hunch, he replaced that cheap unshielded wire he'd used with proper RG-400. The problem just vanished, like flipping a switch. Turns out his strobe light wiring was running right next to it and dumping noise into the line. He felt pretty silly for not using coax from the start.
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nora_dixon
nora_dixon1mo ago
Always use coax for GPS, learned that the hard way.
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