• AutoEZ,TLDetails&MoxGen by Dan Maguire AC6LA

  • MMANAFreesoftware based on MININEC from DL2KQ-EU1TT

  • CocoaNECFreeNEC software for the Mac OS-X Tiger operating system by W7AY

  • OtherMOM-based Software Providers:

    FEA-basedSoftware Vendors:

    AntennaStructural Analysis Software:

    NEC/MININECOrganizations and Resources:

    Other RFand Antenna Software

    (links updated 18 Feb 2013)

    Learn HowAntennas Work!

    LinearDipole - set length to 0.5(half-wavelength dipole) and notice that theimpedance is near 73 ohms. Radiation pattern shown is typicalfigure-8pattern. When a half-wave dipole is close to ground, the impedance isloweredto near 50 ohms. Thus a perfect match to 50 ohm cable.

    -set lengthto 1.27 wavelength. This is called an Extended Double Zeppantenna and produces the maximum gain possible from a simple center-feddipole. Notice that the radiation resistance (impedance) is about 90ohms. This antenna can be matched to 50 ohms by using a seriesinductor.Half of this antenna is 5/8 wave and is a common length for 2m mobileantennas.The 5/8 wave antenna is typically fed against a ground plane (car roof)andis usually matched with a tapped inductor.

    Calculator

    -set lengthof dipole to multiples of 1/4 wave on each side (e.g. 0.5, 1.5,2.5, etc.). Notice how these lengths produce an radiationresistance(impedance) close to 100 ohms. The patterns of these are madeup ofmany lobes (cloverleaf pattern).

    How doantennas produce gain?

    Yagi Antenna Design software, free download 2012

    updated 17 Jan 2006

    LincolnAmateur Radio Club Antenna Class

    Links to Software and other information

    updated ?

    LPCAD - Log Periodic CAD
    Now availablefor Windows 7 OS!
    LPCAD version 3.4 is nowavailable! LPCAD 3.4runs fine underWindows 2000, XP, Vista and Windows 7. Please emailme at rgcox2 (at) gmail.com for details.
    updated 18 Feb2013

    NEC ModelLibrary

    The following files and links point to NEC/AO/YO models of various Hamantennasthat I have simulated and/or tested over the past 30 years as anantennadesigner. The NEC files may be used with any of the NEC-2 or NEC-4programssuch as 4NEC2, GNEC or cocoaNEC, however some of them with taperedelementsmay only be simulated accurately by NEC-4 or other MININEC-basedsoftware.These models will indicate in the CM lines if they need to use NEC-4 or4NEC2.These models have varying degrees of accuracy. Some may be very closetoactual performance. Others may only be an estimate. They are for you,asthe experimenter, to use and improve. This list will grow asI checkeach file before uploading, so check back often. Have fun!

    Yagi Antenna Design Software

    Links:

    Yagi Antenna Design software, free downloads

    VHF NECModels:

    The VHF antennas shown above include the 'raw' element lengths. Thatis, the element lengths are those used with a wood or plastic(dielectric)boom or supported above or below a metal boom with an large insulator.Toconvert these raw lengths into actual lengths used when passed throughthecenter of metal booms, you need to add a correction factor, based onwhetherthe element is insulated and passes through the center of a metal boom,oris shorted directly to the metal boom with a clamp.

    If theelement is insulated when it passes through the metal boom, thecorrectionfactor is approximately 1/4 the diameter of the boom. Forexample,for a 36' (raw length) insulated element passed through the center of a1'metal boom, the correction factor is 0.25', so the actual length shouldbe36.25' when built.

    (updated 16 July 2013)

    Commentsare welcome!

    Download

    contactRoger: email to WB0DGF @ ARRL.NET

    or

    2 Element Yagi Antenna Design

    rgcox2(at) gmail.com

    Best Yagi Antenna

    Roger Cox - Spring Lake, MI