i see a photo of a 27mhz j-pole sold by a French company and in the photos it seems to have a gamma match....so i assume its no longer a J-pole i believe a J-pole is a end fed 1/2 wave with a 1/4 wave matching stub and behaves much like a 1/2 wave
so if it fed with a gamermatch will it work like a 3/4 wave and have a 3/4 pattern so less gain than a 1/2 wave???
photos below
so if it fed with a gamermatch will it work like a 3/4 wave and have a 3/4 pattern so less gain than a 1/2 wave???
photos below