I have just completed building and installing a multi-coax junction box on my tower. I have 9 coaxes coming down the tower and feeding through a 4 inch pvc conduit to the basement. Every time a thunderstorm approached I would have to go behind my operating desk in the shack and disconnect them all. Two of the lines are 7/8 inch hardline with 1/4 inch solid core center conductor. Any lightning strike would have a direct path to the shack- not great!! I had an old aluminum weather proof  box which was used for a chart recorder in a town pump house. Please see the pictures for the construction and finished product. There is also another WP box three feet away to connect the coaxes from the house to a grounding bar during bad weather. The red banana plugs ground the disconnected  coax coming down the tower after they are disconnected. This way there is no path for the lightning to enter the house through the coaxes.