Daily Archives: 4/14/2010

WA5VJB Cheap Yagis — Wood Boom

A couple of weeks ago, I started working on a version of the DL6WU Yagi that I might be able to get going for this weekend’s Moonbounce activities. I cut and mounted all the elements, but frankly, the feed system is a bit more complicated than I would like so I didn’t get it finished. On the other hand, I have constructed the so-called “Cheap Yagi” of WA5VJB before, and its feed is very, very simple: the driven element is a hairpin and the coax is soldered directly to it. Nice, neat and simple. So, I surfed on over to here:

WA5VJB Cheap Yagis — Wood Boom

And started cutting some copper-bronze welding rod to lengths. But something disturbed me: the length of the elements weren’t monotonically decreasing. In particular, director 4 was only 11 inches long, but it was surrounded by directors which were 12 inches long. That struck me as bad. Very bad. So, I tried to search for the original article that these antennas were based upon, and found a scan here:

The original article

Close comparison of the dimensions for the 11 element 70cm antenna reveal that director 4 should be 12″ long as well. So, that’s what I cut. Tomorrow, I’ll drill the holes, hot glue the elements in place, and then solder the feedline to it. And, maybe I’ll try to test record a pass of AO-51 or something to ascertain that it basically works.