Piper J3
Well Known Member
I was having noise in the SL40 comm radio on my RV-12. After a lot of troubleshooting I decided to replace the spark plug caps. I had a suspicion that the 5-ohm ceramic resistor may have been damaged from pulling (manhandling) the rubber caps when removing the plug wires. The rubber cap is easily deformed.
I purchased new NGK Spark Plug Resistor Cover – 90 deg Elbow Type LB05F on eBay for $49.68 for qty (8). These caps are rigid phenolic and should prevent future damage to the internal 5- ohm resistor. Installation is very simple – just unscrew old cap from wire end and screw on new cap.
Radio noise problem is now fixed…
![](/proxy.php?image=https%3A%2F%2Fi.postimg.cc%2FFKKK0Pnt%2FScreenshot-2019-05-20-12-45-57-476.png&hash=19d5758b98d020a1922c68910fb5a4e7)
I purchased new NGK Spark Plug Resistor Cover – 90 deg Elbow Type LB05F on eBay for $49.68 for qty (8). These caps are rigid phenolic and should prevent future damage to the internal 5- ohm resistor. Installation is very simple – just unscrew old cap from wire end and screw on new cap.
Radio noise problem is now fixed…
![](/proxy.php?image=https%3A%2F%2Fi.postimg.cc%2FFKKK0Pnt%2FScreenshot-2019-05-20-12-45-57-476.png&hash=19d5758b98d020a1922c68910fb5a4e7)
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