Yaesu recommends pinning the mast to their rotators. Either way it still
won't stop the antenna from rotating on the mast.
From: "K8RI on TowerTalk"
Usually those things slip for a reason which prevents you from having to
purchase a new rotator. OTOH sometimes they slip just due to a poor mast
clamp. Still it's not a good idea to pin the mast to the rotator unless
you have a rotator that is nearly indestructable and that eliminates all the
non worm gear drive rotators.
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