Is J Pole Truly Omnidirectional Or Not

[Tom Line]

Was on a 2 meter discussion net recently where they all believed and professed that a J pole antenna is truly omnidirectional. This was about one fella having trouble talking to a far station that everybody else could talk to fine. However I think a Jay pole has 1 or 2 small deep nulls because of the matching section. I suggested rotating it a few degrees to see but got over-ruled. I use a Ringo so haven't run into this before. ???

 

[sp5it]

For example 70cm jpole. 2.33dBi difference.

 

[freecell]

https://duckduckgo.com/?q=j-pole+antenna+radiation+pattern&t=h_&iax=images&ia=images

 

[The DB]

Was on a 2 meter discussion net recently where they all believed and professed that a J pole antenna is truly omnidirectional. This was about one fella having trouble talking to a far station that everybody else could talk to fine. However I think a Jay pole has 1 or 2 small deep nulls because of the matching section. I suggested rotating it a few degrees to see but got over-ruled. I use a Ringo so haven't run into this before. ???

A j-pole is not truly omnidirectional as it will have slightly more gain on the side the stub is on as opposed to the other. However, you won't notice the difference in the real world. If you have deep nulls in one direction on the horizon and not another, that will likely have more to do with the layout of the land than the fact that it is a j-pole.


The DB