I was trying to increase the overall performance of the J-pole, in this design. The diagram provided is a more simplified version of the one I did. These are a few of the modifications I came up with. I added a cap on the top end of the PVC. Mounted a so-239 to a split piece of copper tubing, that took the place of the #14 copper wire. And, I also added a short aluminum mast that fit into the lower end of the PVC. I mounted the antenna to a 10' antenna mast and a small tripod on the roof. I tried to add some type of a ground plain but everything I did made the antenna perform poorly. After all my efforts the end result was an antenna that out performs the 1/2-wave colinear copper version, with only one exception. The working model is somewhat narrow banded and still requires more experimentation. Some of the elements must be a little long.
Some comments about the OUTSIDE PVC antenna.
Check out these images of my completed 5/8 x2 PVC antenna, taken after 7 months of service.
Swedish instructions for this 5/8th x2 design! By Roland Johansson, SM6EAT
Check out this 430Mhz Italian version of the 5/8th x2 design! By Franco, IW3HZF
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