Sunday, July 10, 2011

Contest Station K5GO

  • 6 Element 10M Yagi
    • 6 Element 10M Yagi

    • Description: This Yagi is installed on 80 feet of 45G right next to the house. It is the only antenna that is rotated with something other than a prop pitch. It is marginal with a Tail Twister. Although a small antenna by comparison, all the antennas are built in an effort to fool Mother Nature, so this antenna is not light duty using 38 feet of 3" x .125 wall trussed boom and elements that are strong enough to withstand approximately 160 MPH. Over the next year or two we will be doing something to help the 10 Meter position - most likely a large fixed Yagi toward Europe.

    Front 3 elements of 9 element 15M JA Yagi
    • Front 3 elements of 9 element 15M JA Yagi

    • Description: This picture shows the front boom of a split boom Yagi that has 6 elements on the back tower and 3 on the front. It is fixed on Japan at a height of only 30 feet. The terrain advantage is significant and this picture is mainly to show the view in the Northwest direction.

    7 elements on 56' boom at 90'
    • 7 elements on 56' boom at 90'

    • Description: This Yagi antenna has elements that YS says should be good for 157 MPH wind and a lot of ice. It has survived ice storms where the measured radial thickness of ice was well in excess of 2 inches. The 56 foot boom has 20 feet of 3.5 inch 6061-T6 x .216 wall in the center and the end pieces are 18 feet of 3 inch x .125 wall tubing exposed. The antenna is mounted on 90 feet of Rohn 45G and is turned by a small prop pitch.

    6 Element 65 Foot Boom 20M Yagi
    • 6 Element 65 Foot Boom 20M Yagi

    • Description: This is a 6 element 20M Yagi on a 65 foot boom. The elements are rated for between 125 and 143 MPH, depending on which one. The boom is trussed vertically and horizontally. The entire antenna is also painted with icephoebic paint. It is mounted at 70 feet on Rohn 45G and is turned with a small prop pitch rotator. With about 11.4 dBi free space gain and 25+ dB F/B this antenna works very well. This tower is also shunt fed for 160M with about 80-100 radials

    8/8, 114 foot booms fixed on Europe
    • 8/8, 114 foot booms fixed on Europe

    • Two 150 foot towers spaced approximately 70 feet apart support this 8/8 stacked array fixed on Europe. There are two 48 foot booms, one at 150 feet and the other at 75 feet, on each tower. The back tower booms each have 5 elements and the front two each have an additional three directors. This antenna has a lot of gain in the most important direction.

      5 Element 40M Yagi

      • 5 Element 40MYagi
                                  • Description: This started out as a 6 Element Yagi on a 110 foot boom. We decided, with a little help from Mother Nature, to cut it down a little so it is now a 5 Element Yagi on a 90 foot boom. The boom is Rohn 45G, the vertical truss support is Rohn 55G and the side truss supports are Rohn 25G. The elements are all good for 125 - 130 MPH and they are trussed and painted with icephoebic paint. This antenna with its large I Beam boom cradle weighs more than 2000 pounds.This antenna is installed at 135 feet on 33 inch face tower and is turned by an extra large prop pitch with a K7NV/Green Heron Engineering control box. As expected this antenna works very well with approximately 10.3 dBi free space gain and 25 dB F/B.

      80M Four Square
      • 80M Four Square

      • Description: Typical four square using a Comtek box, Rohn 25G tower and homemade insulators using fiberglass rod. A radial system consisting of 60 radials and bus wires is installed. Although we have put up other antennas that worked better (four element wire Yagi at 150 feet) they are hard to keep up. This will be the primary antenna for 80M until we figure out what would be better and survive the wind and ice.

No comments: