Ruining a perfectly good serial cable

[froodley]

Hi, all,

First time poster and inexperienced electronics person here...

I have a little project: I am going to take some regular computer serial cables (DB9 connectors) and chop off one end. Then I'm going to solder a special connector I need on there instead. I have the pinouts, and (*knock on wood*) I think I can handle that.

The problem is, the special connector only uses 3 of the 9 wires (RX/TX/GRD). I am not trying to create a fire hazard or a communications issue, so what should I do with the other wires? Do I need to disconnect them from the head I'm not removing? Or is it adequate to make sure there is a good amount of the sheaf coming down past the end of the metal wire?

I appreciate your help in advance.

 

[froodley]

If I want to remove them from the head that's staying on, can i just clip them at the head, or do i actually need to unsolder them?

 

[(*steve*)]

what should I do with the other wires?

Just clip them off. There is no fire hazard. Clip them cleanly so there are no wires protruding from the cut ends.

RS232 allows any lead to be shorted to any other lead indefinitely without damage to anything (other than functionality), so even if you do have a short, it should not break anything.

3 wire RS232 is very common.

 

[froodley]

So it doesn't matter where I clip them, I take it? I think my babies will look less monstrous if I don't damage the outer sheath at the db9 side so I'd rather just clip them just inside the remaining inner sheath on the other side.

Thanks for your reply, it was very reassuring

 

[(*steve*)]

If the cable is going to be very long, clip them at both ends. There's no need to connect a long antenna to a signal input where it's not needed

 

[Militoy]

Without knowing the application, I typically wouldn't stick out my neck and say clipping is OK - but in this case, "RX/TX/GRD" sounds a lot like EIA/RS232, or CANbus, or some other sweetly forgiving serial com bus. I will "pick a nit", though, and point out that technically - there isn't such a connector as a DB9. It's actually a DE-9. I know - I know, common usage, blah-blah-blah. But, if we're working with technical stuff - we might as well be technically correct ;-).