I can't see that it makes much difference, but is there any deference which
way the coax is connected to a J pole antenna. Is it better to have the
centre of the coax connected to the main element or the stub?
I notice that most if not all J pole designs on the net have the centre of
the coax connected to the main element, however when I refer to a 1977 ARRL
antenna book it has it connected the other way.

Is there any difference?

Peter