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5ele homemade DK7ZB yagi for 70MHz based on a 50MHz TONNA

The two end sections of the boom extending beyond the support, was replaced with new 20*20mm profiles from the local hardware store. This was because one had been destroyed in a storm, and the other was simply misplaced. As far as I can see you should be able to use the original boom aswell. The elements from the TONNA were reused by sawing them down to the correct lengths. I started by centering director 1 and director 2 on the old part of the boom above the support. The original dipole matching shunt and box were removed and the M5 studs fitted into a new balun box (standard item for electrical installations). You can also use the original dipole box, but it is a bit small. In any case do not forget to shunt the ground part of the coax connector to the boom for proper balun effect.

Also have a look at Paul GW8IZRs approach, which is even more simple, since it leaves the elements in the same positions as the 6m design, and reuses part of the original matching arrangement.

Also check out my 7ele DK7ZB

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