View Single Post
Old 3rd July 2020
This is still the best thread on this topic. There's another on GroupDIY where John reinforces the same concept, which is great. I have a feeling that a lot of people finding this thread are doing something like what I'm up to...

I'm getting ready to do a bunch of in-console unbalanced wiring using twisted pair with a foil shield and a drain wire. This is a 4.0mm 100Ω cable with a very low core-to-core capacitance -- Canford FST. But you could use Belden 9451 the same way. Typically, the cold and the shield will be tied at the source end, and the shield will float at the load end.

I'm wondering if anyone has tried the tie-the-shield-to-the-other-end-with-a-small-capacitor approach in a high RF environment, and determined that it helped. I'm mostly curious what value was used, and if a simple C0G MLCC would be sufficient.

I'm also wondering if there's a major reason to veer towards a spiral or braided shield in this scenario, as it's really quite a pain in the butt to deal with anything other than a foil shield and drain wire for in-console work (no matter how much everyone loooooooves Mogami). I haven't really looked into W2944.

As an alternative to twisted pair, I did find a couple of coaxials that might work: Belden 8417, and Belden 9264. The catalog does give a nod to their audio application. Both conductor and drain are tinned, which is nice. 9264 is...uh..oval shaped. 8417 is grey, sandwiches the drain between two foil shields, and has a paper wrap. Both are in the neighborhood of 3.5mm O.D.