Tooooo many opinions ....

[KE4VCU]

When attaching leads to a copper tubing J-pole, does the solid center conductor go to the short side or the long side ?  My terms are not very technical, but it helps to minimize confusion.
Thank You.

Bobby
KE4VCU

[KF6QEX]

http://www.alpharubicon.com/elect/jpolejaden.htm

http://en.wikipedia.org/wiki/File:Antenna-j-pole-diagram.svg

[WB6BYU]

It shouldn't make any difference.

In some cases it may, depending on the length of the coax and the mast, the exact
construction of the antenna, etc.  Either can work well in some situations and not
in others, but it is very difficult to know ahead of time.  So just choose whichever
is easier mechanically.

[W5DXP]

When attaching leads to a copper tubing J-pole, does the solid center conductor go to the short side or the long side ?

The J-Pole is not a well-engineered antenna and that's why you don't see many of them in commercial applications. It is good engineering practice to install a balun at every BALanced to UNbalanced junction in the system. There are two of those junctions in a J-Pole antenna and not a balun in sight unless one rolls an ugly balun at the feedpoint which is a mechanically difficult implementation. A J-Pole is basically a Zepp antenna for vhf/uhf and shares the same common-mode problems. One will have common-mode signals on the coax no matter which conductor goes where.

Has anyone tried feeding a J-Pole with twin lead attached at the 300 ohm feedpoint?

[G4AON]

If you want to try a 6m J-Pole from 450 Ohm slotted ribbon, see my page at:
http://www.astromag.co.uk/j-pole/

73 Dave

[KB5UBI]

Cecil,

I've built a few J-poles by feeding at the 200 ohm point using a 1/2 wave coax balun. I found them easier to tune and they loose their ground interaction. It was easy to find the 200 ohm spot by moving the feed point up and down until it had a 1:1 SWR.

I built a temporary one years ago for a Public Service repeater (460 mhz). You could use that San Antonio repeater from Austin with a mobile with the balanced fed J-Pole, but that went away when it was replaced with a commercial down-tilt antenna.

That said, I agree the J-Pole is a marginal design but it is easy to build.

KB5UBI

[K5KNE]

Try it both ways and see which one seems to be better.  It has been either way sucessfully.

Walter K5KNE