[RFI] Noisy LED shop lights

[Jim Brown]

On 6/13/2018 12:48 PM, Stephanie WX3K via RFI wrote:
> Here is a helpful link
> https://www.digikey.se/Web%20Export/Supplier%20Content/Lambda_285/PDF/TDKLambda_all_about_emi_epmag.pdf
>
> If you search Amazon by entering EMI filter you will find a variety for different applications.

BUT THE LINK IS WRONG! It is the EMC compliance tech's view of the world.

These filters work ONLY if properly mounted and built INTO equipment. In 
general, they do NOT work for most real world problems that put noise on 
the power line as current on the green wire.

The most common cause of noise coupling to and from power and signal 
wiring is that the green wire, or the cable shield, fails to contact the 
shielding enclosure at the point of entry/exit. This puts noise current 
on the green wire of the cable shield, and it causes noise current on 
the cable shield to enter equipment. Neil Muncy, ex-W3WJE (SK), first 
exposed this in 1994, and a fellow member of the AES Standards Committee 
Working Group on EMC named it "The Pin One Problem." See my website for 
a lot of tutorial material on this.

The only fix for this (without modifying equipment) is a ferrite common 
mode choke. And simply clamping a few onto the cable does NOT WORK at 
HF. Those clamp-ons are designed for VHF noise. Study

k9yc.com/RFI-Ham.pdf  and

http://k9yc.com/KillingReceiveNoise.pdf

73, Jim K9YC