Thanks for the response. I understand what you're telling me. What I need to know is - when someone on the Tesla list says "use 3/8" tubing for the primary", do they mean the industry standard 3/8" tube size (that has an OD of 1/2"), or do they mean "use tubing that measures 3/8" OD" (which would actually be industry standard 1/4" tubing).
Tim,
When someone says, "use 3/8" tubing for a primary", they mean use tubing that has a true 3/8" outer diameter. This soft tubing seems to be sold in a different fashion such that it's sold by the actual outside diameter. So 3/8" tubing is actually 3/8" OD. At least that's how I understand it. But in any case in TC work, the tubing diameter refers to the actual OD.