Rewired an ATR833 radio

[Ulmo133]

Hello,

I want to rewired my radio and installed the headset connector in the column in between the seat. The previous owner does a sh...ty job and communication are poor and unstable.
In attachement the wiring diagram of the radio.
I have some questions :

• Can I put the PPT-R (or L) cable (Pin 17/15) inside the shield cable as I have shielded cable with two cable inside already or it's mandatory to leave the microphone cable alone in the shielded cable ?
• Pin 14/5 or Pin 8/6, made for gliders, they said to short circuited if unused. So I understand these two different way : 1) I connect Pin 14 and Pin 5 together and that's all or I connect Pin 14 and Pin 5 to the ground.
• Pin 4 : same thing, it's unused so do I have to connect it to the ground ?

Thank you for your help.
Good day and good flight.