WB4IUY's Random Blog

I've been in Amateur Radio since 1974, and still find new and interesting things to do. I like to build, restore, and operate on the air. This is a blog of various info about my Ham Radio operations and activities, projects, and opinions. Visit www.WB4IUY.net for the lowdown at WB4IUY.

Sunday, November 12, 2017

Antenna work - 11/12/17

I completed my HF yagi today, for installation on the rebuilt tower. For those who don't know, my tower of 23 years was torn down in a storm in April 2016, destroying all of the 17 antennas that had served me well for all those years. Everything from the vertical that had it's tip at 138' up, right on down to the lowest antennas that were only 30' up. In addition to storm damage to the house and workshop, the tower and antennas system created such a mess that I had to rent a crane / man lift to get it all down from the surrounding trees and untangle / remove the mess of tower that loomed over our home. You can see the system as it was before the storm on my website at www.wb4iuy.net , mouse over the [WB4IUY] in the toolbar at the top, and click on [Antennas] in the dropdown that appears. 

Today I completed the feed harness for the driven elements, built and installed a new RF current choke on the boom, and tuned this 6 element Force-12 HF yagi. I got this antenna used for a great price...it's a $1200+ antenna that I otherwise would have never bought, it just needed a little TLC to bring it back to life. It is a trapless design, perfect for operating with high power. 

If all holds well, it'll be going up on the tower next weekend, and I'll start the rebuild of the next antenna for installation. I can't wait to get this baby in operation!

 RF Choke wound from RG-214 and attached to the boom.


 Bottom view, coax attached and jumpers installed between driven elements...


 Side view, feedline attached and jumpers in place between driven elements...


 Shack side of RF choke feed strapped to the boom...





 Antenna tuned on 10m, had to shorten the elements, drill, and re-rivet to set length...


  Antenna tuned on 20m, lengthened the linear loads a little to move the sweet spot down the band a little...


  Antenna tuned on 15m, had to lengthen the elements, drill, and re-rivet to set length...


 Antenna analyzer connected for testing...


 15m elements lengthened a little...


 10m elements shortened a little to move the sweet spot up the band a bit...

Dave WB4IUY
http://www.WB4IUY.net