ok here is 300 foot of 14 gauge aluminum wire on the spool I picked up from amazon. It has a crank to real in the cable after landing. I am tempted to go ahead and get the next 100 foot on the roll. I will need to add connectors and solder them together. They will be insulated with shrink tubing. I have a label maker and I consider labeling the tether every 10 foot or something as a visual indicator to see how much of the tether is in the sky.