External Emitter Build Diagram?

Hey All,
I'm trying to find a diagram of whats needed to build a couple of external emitters for my usb-uirt so I can control both of my cable boxes.
All I've really been able to find by searching is that the plug is a stereo 3.5mm but I haven't found any wiring diagrams for it or if there is any other components (apart from the IR LED but which one/type) such as resistors or anything like that
Can anyone point me in the right direction ?
Buying premade stuff is not really an option, it will cost me more in freight to Australia than the cables are worth
TIA
Paul
I'm trying to find a diagram of whats needed to build a couple of external emitters for my usb-uirt so I can control both of my cable boxes.
All I've really been able to find by searching is that the plug is a stereo 3.5mm but I haven't found any wiring diagrams for it or if there is any other components (apart from the IR LED but which one/type) such as resistors or anything like that
Can anyone point me in the right direction ?
Buying premade stuff is not really an option, it will cost me more in freight to Australia than the cables are worth
TIA
Paul