I can´t find anything in the wiki how to adapt the old 5pin connector to the pixhawk 6 pin telemetry connector. Maybe someone could assist? Something like this would be fine:
DF13 5 |||||| ||DF13 6
Pin 1 5V VCC||||Pin 1 5V VCC
Pin 2 ||||||||||Pin x
Pin 3 ||||||||||Pin x
Pin 4 …
Pin 5 …
Cheers
Gregor
PS: Why is the no “ready to use” cable avaliable?
check this page out…pixhawk.org/modules/pixhawk
Scroll down and you will see…
The device you are trying to interface should have the pin outs labeled, right? Use them to splice to the right wires.
Yeah, there should be a cable set table to splice various revisions of old hardware to new but then what fun would that be. 
Ok in between I found the schematic of the pixhawk. So I pulled out the cables out of the 5 pole housing and the same with a new 6 pole cable. I made this very carefully but the cables did not held in the 6 pole housing anymore. 2. attempt with soldering the 6 pole cable to the telemetry cable worked for me. 3DR sells a cable for the new external GPS with APM, but they did not made it for MinimOSD or XBee with Pixhawk. I think its a step back. 