Fishtape
I used an electrician's fishtape (from a tool rental store). It is a stiff, springy wire that comes on a reel, which electricians use to pull cable through walls and attics, etc. I drilled an access hole near the top of the mast, just below the masthead fitting. The hole size fit a rubber grommet with an inside diameter of 1/4". I pushed the fishtape down through the mast from the top to the bottom, attached a length of braided nylon cord (about 3/16" size), then pulled the fishtape and the nylon cord back through the mast and out the access hole. I removed the fishtape and attached the coax cable to the nylon cord with electrician's tape. From the bottom of the mast I pulled the nylon cord with the coax attached until the cable reached the bottom. I drilled another hole in the mast about six inches from the bottom. With a coat hanger I was able to work the coax out through the bottom hole. I slipped rubber grommets over the coax at both the top and bottom and worked the grommets into the holes in the mast. Finally, I soldered coax PL-259 connectors to both ends of the coax cable. I don't think I could have done it without the fishtape. That is the key. Good luck.Dale WileSandpoint, Idaho