That is really helpful, thank you. It is difficult to see how even 6mm cable would be easily run given the setup at the bottom of the masts. On the basis of what you have said I will wait until the masts are down to replace the cables. There are some other jobs that can be done at the same time.
Did you leave enough cable at the bottom of the masts to reach the nav station or did you put in a connector near the bases?
Mark & Nicky Barter