Used PVC plus pipe wrap
On my 222, I slid two connected pieces of pieces of 1.5 inch pvc pipe with pipewrap around them (secured with cable ties) inside the mast. On the 222, there was only one place inside the mast where there was an obstruction (i.e., at the spreaders where there was a bolt that went through the mast)and I was able to angle the pvc pipe so that it went around the bolt. Then I ran the coaxial inside the pvc pipe. I have never heard any cable-slap noises (pipe-wrap would deaden any noise) and the PVC pipe also keeps the cables clear of any sharp objects such as screws. Once I ran the coaxial for the antenna through the mast, and also rewired the running light on the mast, I ran a string inside to make the pulling of other wires (e.g., I'll probably add a masthead light at some point) easier in the future.Hope this helps. Good luck with your project.Dave