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  1. 03-12-2012, 03:30 PM #1
    AF5AD
    AF5AD is offline Ham Member
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    Default Antenna Modeling Software

    I have a general question about antenna modeling software. When I use formulas for wavelength using the value adjusted for velocity factor of .95 (234/Mhz for vertical 1/4 wave) the answer is shorter, and seems more accurate, than using modeling software. MMANA and others seem to use the speed of light in a vacuum and therefore give answers indicating longer antennas.

    Why is this; can it be adjusted in the programs?
  2. 03-14-2012, 11:29 AM #2
    AF5AD
    AF5AD is offline Ham Member
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    Default

    Extra research I've found that the velocity factor of .95 is for the wire; not in air which is actually .9997. Still don't know why MMANA doesn't consider this is calculation. I've selected cu wire for medium with little change.

    ?

    Quote Originally Posted by AF5AD View Post
    I have a general question about antenna modeling software. When I use formulas for wavelength using the value adjusted for velocity factor of .95 (234/Mhz for vertical 1/4 wave) the answer is shorter, and seems more accurate, than using modeling software. MMANA and others seem to use the speed of light in a vacuum and therefore give answers indicating longer antennas.

    Why is this; can it be adjusted in the programs?
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