I use a pulley and a line.  The wire holds the antennas away from the mast. 
That way if the feed lines need to be worked on, I just run the extra line 
through the pulley bring it down fix it and pull it up.  Kind of like 
raising and lowering the flag.  A little metal doesn't do much harm.  The 
other thing a friend of mine did, was place a 1 meg ohm resistor across the 
feed point.  The ohm meter is a much easier way to see if the feed line is 
broken, than brining the antenna system down.