Originally Posted by gotyoke
Sorry for digging up an old thread. I'd like to understand better when one would and wouldn't use shielded:
Why should the servo to trim power be shielded, but the relay to servo trim input can be unshielded? Can the servo power leads also be unshielded? I ask because the power going into the servo from the relays would throw off as much, if not more, electronic interference than the servo to trim leads, all while passing near and alongside a whole lot more wires and components.
There is no electrical reason to use shielded cable for trim servos - but that is what I use. As I mentioned, a single, four #22 conductor shielded cable has all the wires you need, and the single cable provides for a much more durable wire run than a bunch of individual wires.
For LED strobes, the three #20 conductor shielded cable as I mentioned does what you need, as well as provides a little protection agains RFI.
This has worked well for me on three RVs.