Where to buy thick diameter cable for DIY RCA interconnects?

The strain I encountered was from the jacket, not the solid core. That said, I don't use RG-6 on purpose, but if it's laying around I'll use it in a pinch. Wouldn't you? Or would you rather listen to nothing? 😀

My preferred cable depends on the application. From pre to power amp you could use barbed wire... Not so much for a turntable 🙂