Silicone caulk? This is not a good situation. Silicon will deteriorate from UV and will not offer any protection after year two. I'm sorry to tell you this but you should now remove that and seal your antenna with Dicor or another urethane based sealer. An additional trouble is that no sealer sticks to silicone, not even more silicone so you will have to use a caulk removal product to get the last vestiges of the silicone off the surfaces you want to seal.
Sorry to give you this after the fact.