VHF Yagi Ideas for Simplex Work

Some local hams have been experimenting with VHF simplex for communicating up and down the valley. The guy who usually leads these experiments is located in Brownsville and has his VHF vertical mounted on a 40 foot tower. He is able to communicate with other hams up and down the valley depending on the other hams configuration. I can communicate easily with him from my home QTH but I am deaf to all but one other local ham on simplex.

My VHF station is spartan at best. I use a 4W Baofeng handy talkie connected to a discone antenna that is up about 10 feet. I get no gain from the discone. This setup works real well for hitting the local repeater and for limited local simplex. I started thinking about the geographic location in respect to other stations in the valley and plotted the following map:

2015-06-30_7-16-07

My QTH in Brownsville is in the lower right hand side of the map. The Rio Grande River is the US-Mexico border and the Gulf of Mexico is to the East. To cover the valley I only need a Beam width of about 126°. I started thinking about building a 2 element yagi vertically oriented and came up with the following azimuth pattern using EZNEC:

2015-06-30_8-51-10

This antenna would give me a 133° beam width and a gain of 7.5dB over what I have now. My only concern is the rather low take off angle of the main lobe. Clearly the higher the better for this antenna but it looks like it would be a good starting point for experiments. Should be fairly simple to build from PVC and aluminum tubing. Will post more as I progress on actually building this.

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