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Old 02-13-2019, 09:05 PM   #1
Cave
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Default Radio Frequency Interference

Recently I noticed that an LED flashlight I was using near the engine flickered whenever the engine was running... the closer I held it to the distributor the more profound the flicker. Then I turned the LED shop light on, easily 8' from the car, it also flickered. I suspected some sort of EMI was causing the trouble. All ignition was stock except for modern points /condenser.

In a move to minimize the RFI I changed to a modern dist. cap but found that the wires that came in that kit were solid and didn't reduce the interference at all, so I did some digging and found that spiral wound ignition wires are intended to cut emissions with very little current loss.

20190213_200206r.jpg

I bought a set of cut-as-needed cables and fit them to the new cap and plugs. Voila! NO RFI, not even if I hold the LED flashlight 1/4" from them. At first glance I'm very pleased, she fired right up, idles and performs just right. And I can use my electronics, LEDs, etc. without risk of EM damage.

YMMV, but am posting this for what it's worth.
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Old 02-14-2019, 12:29 PM   #2
Tacoma Bob
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Question Re: Radio Frequency Interference

So..........I'm not a "Sparktrician" . Would there be issues if a car has LED tail lights and now the new LED head lights?
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Old 02-14-2019, 01:26 PM   #3
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Default Re: Radio Frequency Interference

I noticed some comments on the early V8 page that indicated just such issues, but I can't speak to them directly.
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Old 02-14-2019, 03:53 PM   #4
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Default Re: Radio Frequency Interference

Thanks for posting, Cave. Something I was unaware of. Great detective work and perfect (only?) solution. Good point to add to the (-) side of the led discussion.
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Old 02-14-2019, 10:00 PM   #5
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Default Re: Radio Frequency Interference

LED's are susceptible to RFI.
A small (.01) ceramic disk capacitor placed across the input terminals will sometimes cure the problem. It depends on the interference level.

Last edited by Pete; 02-15-2019 at 12:24 PM.
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Old 02-14-2019, 11:13 PM   #6
Mike V. Florida
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Default Re: Radio Frequency Interference

Quote:
Originally Posted by Pete View Post
LED's are susceptible to RFI.
A small (.01) ceramic disk capacitor place across the input terminals will sometimes cure the problem. It depends on the interference level.

And in the case of the replacement bulbs, quality of design and manufacture.
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