Radio Shack has black cords? I will check them out, but last time I was in one all they had was cell phones and computer things. No electronics any more.
I just received an email from the supplier of the cord with the thinner wire. They told me that 20 gauge was rated up to 2 Amps and that few sewing machine motors were over 1.5 amps with most being under 1.0 amps. So there would be no problem using it.
Perhaps I'm a bit paranoid, maybe.
Joe