This is considered a double-post (frowned upon). You could simply have added info to your 1st post.
Never post your email address like you just did. Everybody would understand
norm[dot]champagne at sympatico[dot]ca
or other "visual code" non-robots can decipher. The reason is: defense against automatic/robotic address/data harvesting.
• Third: Usb to RCA or even coax is not likely "...One wire contains a path for a five volt (5V±5%) power supply; two are twisted-pair data wires; and one is a ground....".
• Fourth: thinking "Wireless" might be your best-and-most versatile way to go, though the costs might be greater.