Tame Your Coax Choke

 Owen Duffy simulated a Common Mode Choke (CMC) using RG316 coax and 2643251002 toroid ferrite core. See his post here.

I found the double-shielded RG316 coax I was using had a life of its own with regards to routing. My understanding is that windings close together boast capacitance, which can negatively affect the choking performance, especially at the high frequency end of the HF spectrum.

I designed and 3D printed a part which solves this.

The part is a spider which fits in the center of the core. It has channels to define the path the coax takes through the core, so that they are equally spaced and minimize inter-turn capacitance.

An opposing theory would say that the permittivity of the material used (in this case PLA) would increase any capacitance. Perhaps, but at least it looks neat.