[RFI] Ethernet RFI and connector wiring

Alan NV8A (ex. AB2OS) nv8a at att.net
Tue Jan 25 11:04:02 EST 2005

OK, I have found something very strange about all these "Ethernet RF 
Filters" I bought from the local computer store (3 turns of CAT5 cable 
thru a toroid of unknown composition and shrinkwrapped, with an RJ45 
male on one end, RJ45 female on the other):

The conductors are connected to the socket (marked "T&B," which I assume 
is "Thomas & Betts," a well-known and reputable manufacturer) according 
to the color-coding and numbering on the socket, but the color-coding 
and numbering are weird:

1 Orange/White
2 Orange
6 Green
4 Blue
5 Blue/White
3 Green/White
7 Brown/White
8 Brown

IOW, pins 3 and 6 are interchanged at the socket end, while the 
conductors at the plug end are connected in the normal sequence.

Where on earth did this wiring sequence spring from?

It looks as though the only thing I can do if I want to keep using these 
things is cut off the plugs and install new ones with weird wiring to 
match the weird wiring at the socket end.

Alan NV8A

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