Here is the end product - the bare copper wire at the bottom is connected to the 3 drain wires from the signal cable and a 4’ rod pounded into the soil, the valve cable splice is on top. All with waterproof wire nut connectors in a NDS PRO Valve Box - 12" x 17" x 6"
I meant to order a box without tapered sides, so it is a little tighter than I had planned 
The blue thing at the bottom right of the box is an ant bait trap as I was getting swarmed when I was sitting on the gravel doing wiring. 
All seems to be working beautifully!
