I don't have access to mine, but I think there is supposed to be an O ring near the opening in the cone. If there is a shallow groove there, it's missing. Hard to tell from picture.
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'The Silver HamShack' (2007 International 22FB CCD 75th Aniversary model)
Multiple Yaesu Radios inside and many antennae sprouting from roof, ProPride hitch
2012 shortbed crewcab 4x4 Toyota Taco TV with more antennae on it