Tightly wrap the connectors with 2 layers of rubber tape (butyl). Notes: Rubber tape should seal entire connection and extend 1 inch beyond antenna connector/cable assembly. Coax-seal (rubber tape) works very well in this application.
Step 3. Covering Rubber Tape with Electrical Tape
Tightly wrap the rubber tape with 2 layers of electrical tape. Note: Electrical tape should extend 1 inch beyond rubber tape to ensure full coverage.