80 Meter Band Vertical Antenna

Minggu, 14 Februari 2010

80M Vertical Antenna with Capacitance Hat

  • 80 Meter vertical antenna
    80 Meter vertical antenna
  • Plot
    Plot
  • SWR Pattern
    SWR Pattern

  • Simple wire antenna;
  • Cheap to make, using readily available materials;
  • Low angle radiation, with rejection of high angle signals;
  • Wide bandwidth, with resonance at the 80M DX window (3.790-3.800 MHz); and
  • Maximum height is 40 feet (limitation due to treeheight).
Design:

Since the use of a full ¼-wave vertical was out of the question because of space reasons, it was decided to use a smaller vertical, and load the top portion of the antenna with a capacitance hat. Based on modeling results, the following dimensions satisfied the design requirements:


Wire Lengths of Antenna Described for 3.800 Mhz
Wire Number     Length    Included Angle
    1                      11.89 m       (39') N/A
    2                      5.84 m        (19'-2") 29º
    3                      5.84 m         (19'-2") 29º