[CQ-Contest] Antenna slippage on mast

[Guy Molinari]

I have a large 20M monobander with a 60' boom.    It seems that whenever the winds exceed a certain speed I will subsequently need to climb up to 160' to repoint the antenna.   My 40M 4 el beam doesn't seem to do this.   It is definately not rotator slippage because the 15M monobander is lined up just fine.
 
Any tips/tricks?
 
Thanks in advance,
Guy, N7ZG