[Elecraft] K3S RJ-45 Pin Alignment

[Jim Brown]

On Sun,5/1/2016 6:19 PM, Michael Blake wrote:
> The plug and jack are described by the number of available contact positions and the number of contacts installed in those positions.

The proper wiring of Ethernet cables REQUIRES that color code be 
strictly observed. An Ethernet cable is four twisted pairs, each having 
a different twist ratio. There's a Brown/White pair, an Orange/White 
pair, a Green/White pair, and a Blue/White pair.

Those four pairs each carries a separate signal, and it is critical that 
crosstalk between pairs is minimized. Crosstalk rejection is provided 
two ways -- primarily by twisting, AND improved by each pair having a 
different twist ratio.

In other words, simply having DC continuity between pins at each end of 
the cable is not enough -- they must be correctly paired, and those 
pairs most tightly twisted (for better noise rejection) are wired to 
their assigned pins.

73, Jim K9YC