Howto build your E1<>RJ45 cable

We used a Cat-7 Ethernet cable to build our E1<>RJ45 cable to connect the BTS with the BSC.

Things you need: * one Cat-7 Ethernet cable * two twinax plugs (BR2) * some heat shrink tube * soldering-iron * multimeter (optional) * a sharp knife :)

=== Step-by-step guide ===

'''One:'''

Take your cable and cut off one of the RJ45 connectors. Now use a ruler and make a slice so you can strip around 15 cm from your cable.

Image(IMG_0960-1.JPG, 15%) Image(IMG_0960-2.JPG, 15%)

'''Two:'''

Split the wires from your cable. We need pin 1 and 2 for '''RX''' (green white/green) and pin 4 and 5 for '''TX''' (blue white/blue), you can use a multimeter if you are not sure you got the correct wires. Cut off the other wires we do not need them (yet).

Image(IMG_0960-4.JPG, 15%) Image(IMG_0960-5.JPG, 15%) Image(IMG_0960-7.JPG, 15%)

'''Three:'''

Sort your twinax plugs to make sure you build them in the right order. ;)BR
We used heat shrink tube to stabilize our cable around the plugs.

Image(IMG_0960-9.JPG, 15%) Image(IMG_0960-11.JPG, 15%)
Image(IMG_0960-12.JPG, 15%) Image(IMG_0960-17.JPG, 15%)

'''Four:'''

Now you can put everything on the first part of the cable and assemble it. Use a soldering-iron to fixate each of the two pins of the plug with your wires. You do not have to worry about the polarity inside the twinax plug.

Image(IMG_0960-19.JPG, 15%)

'''Five:'''

Repeat step '''three''' and '''four''' to build the second plug.

'''Done.'''

Image(IMG_6379-1.JPG, 15%)

Detailed pinout {{{

Signals on the RJ45 plug:
____________
/ / / |
/ / / /|
/ /_______________/ / |
/ ________ / |
/ / / / / / / / / / / |
/ / / / / / / / / / / /
/ /_/_/_/_/_/_/_/_/ / / | | | | | | | | | | | / | |8|7|6|5|4|3|2|1| | / | |_|_|_|_|_|_|_|_| |/ |___________________| | |/
\______/

1 = RX1
    2 = RX2
    3 = NC
    4 = TX1
    5 = TX2
    6 = NC
    7 = NC
    8 = NC

Signals on the twinax plugs:

E1 Transmitter:
           _            
       .-''   '`-.  
     .'           `. 
    /     1      2  \
   :    ##     ##    ;
|    ##     ##    |
   :                 ;
    \ ############# /
     `. ######### .'
       `-._____.-'
|    ##     ##    |
   :                 ;
    \ ############# /
     `. ######### .'
       `-._____.-'

1 = RX1
    2 = RX2

Note: The drawings are showing the plugs point of view. 
      Note: This is a differential connection with symetric signals
            so you do not have to care about the polarity.

Cable connection on the BS11:

~~~~~_________~~~~~~
 /        oo   oo       \
 \        12            /
  ~~~~~|_______|~~~~~~ 

1 = RX (E1 Transmitter to that port)
    2 = TX (E1 Receiver to that port)
}}}