There is also info that can be read about Self Built Cables using PC Triple C Solid Wire on the Double Helix thread in the Agon Cable Section.
I intend on making these out of Wire I own.
My own experiences had, experiencing the wire used in other systems are shared on a few threads, easy to find as a search.
PC Triple C / EX is also a wire that is not plated, but coated with a Silver Sheath, the methodology is seemingly like one Koetsu has used on much finer wire for their Coils.
The Link will show a variety of Cables, a regular search over a period of time will show items that are quite affordable.
https://www.fromjapan.co.jp/japan/en/item/search/PC+TripleC/Al_11_Yh_RaSuBpRmMrMv_N_N_0A00ja00_N/