"Don't use the blue USB!"

[Deleted member 1451080]

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[blekenbleu]

my SC2 came with some belong to trash junk

Typical. Developers do all sorts of janky last minute stuff to pass FCC,
including things that actually increase radiated RFI
(but generate cancellation nulls at measurement positions).
They likely used a shielded & choked USB cable for testing,
then cost-reduced for production.

Because of the bizarre way FCC specifies measurements (integrating over time),
Lexmark patented sweeping their processors clock (AKA spread spectrum)
which increases the bandwidth with which they interfere
but reduces time-averaged power at any single frequency.
That is IMO not unlike tricks VW played to pass diesel emissions testing.

 

[Deleted member 1451080]

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[Deleted member 197115]

BTW, This is what I've used as a replacement, stock picture doesn't show it but it comes with ferrite choke on one end. Very high quality cable, UGreen makes good ones.

 

[Deleted member 1451080]

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[blekenbleu]

Do you know

I am out of date for even FCC, which has 4 or so classes for EMC (e.g. consumer vs industrial).
https://www.academyofemc.com/emc-standards

https://www.intertek.com/uploadedFi...ectrical/Media/PDF/EMC_Testing/EMC-Trends.pdf
Europe handles EMC under CE, while U.S. separately certifies safety vs EMC vs energy efficiency.

Since U.S. and Europe have different frequency allocations,
that would seemingly involve at least some unique tests.
Even U.S. and Canada standards differ somewhat, or at least used to.

 

[Deleted member 1451080]

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[blekenbleu]

USB was an international standard

Like HDMI, USB is an industry standard, promoted by a consortium.
Those who abide by such consortiums' self-imposed requirements (e.g. membership payment)
get to display their licensed symbols.