I don't have access to that book or the illustration so can't say what
that 'dot' represents. One way to figure it though, is that feed line
a singe conductor, or two conductors? If it's a single conductor it
probably just makes a direct connection to the antenna. If it's two
conductors, there's probably an insulator of some kind there, and each
conductor goes to one 'side' of the antenna. Make sense
- 'Doc