building a VK2JDS 3 element yagi for 2 metre band

  • building a VK2JDS 8 element yagi for 2 metre band
  • building a VK2JDS 10 element yagi for 2 metre band
  • DL6WU Yagi design page

    PORTABLE 3 ELEMENT YAGI FOR 2 METRES by Dave, VK2JDS (October 2006)
    This antenna was designed to be taken portable up on hilltops or buildings etc and operated
    from a 2 metre handheld.
    It can be hand-held on the boom back near the reflector without upsetting the gain or vswr.
    Originally this antenna was designed and assembled with the driven element mounted midway
    between the reflector and the director however this didnt work so well , and had a best
    vswr exceeding 1.6:1,so much experimentation resulted in the final design which is seemingly
    unaffected by handholding the boom or mounting it on hastily made structures while out portable.
    The VSWR  curve is thus:
    144.1	1.5:1
    145.0	1.3:1
    146.0	1.2:1
    147.0	1.2:1
    148.0	1.4:1
    The element lengths are:
    Reflector	950mm
    Driven		940mm overall
    Director	855mm
    The spacings are:
    Reflector to driven	500mm
    Driven to director	330mm
    Driven element details:
    The driven element consists of 2 pieces of 10mm aluminium tubing mounted on a piece of perspex.
    2  holes are drilled through each element to mount them onto the perspex and they are fixed
    with 3/16" machine screws and nuts. The perspex is then mounted to the boom with 2 longer 3/16"
    screws and nuts.You can utilise whatever bolts you have available, otherwise visit the local
    hardware store.
    This antenna works very well against a omnidirectional antenna, its light, small and using thin
    coax scrounged from mobile phone instalations its excellent for useage out-bush.
    Refer to the pictures for more detail.

    1. the antenna

    2. the feedpoint