BTW, I have seen some plans for a Jpole identical to the one I built,
and they call for several turns of coax as a balun for the thing. I
really don't think that is needed. I measured out 1.1:1 SWR @ 50 ohms in
the middle, and good SWR across the band.


Thats not the reason for the Balun. The balun is to keep the feed line from
radiating