Skyloop Antenna Calculator

 home: ky8d.net/free 

Introduction    ↑   → 

A free-running, off-line calculator for determining the radiation resistance of non-resonant loop antennas: circumference 1/3 lambda and below. Handles arbitrary irregular polygons (although R_rad accuracy will suffer if made concave). Answers given are generalized approximates according to a somewhat dated formula based upon inclosed area, frequency and velocity factor. Exporting to an NEC modeling program is recommended.

Easy to use:
1. Fit to suit, building an ad hoc polygon from a Google Earth screenshot of your own QTH.
   • Use any art-program GUI’s raw integer mouse-position coordinates for determining vertices.
   • Enter those into the Vertices (X,Y) array.
   • Re-scale by percentages until values deemed to fit.
2. Alternately, generate an ideal polygon of N sides for a full-wave loop of any given frequency.
   • Click to transfer values to the Main tab.
3. Once polygon vertices are established, play with the values like so:
   • Modify overall size with the Rescale % widget.
   • See the effect of wire velocity factors using the VF (%) wiget.
   • Observe how Rrad changes for various frequencies.
   • Efficiently iterate your way by trial-and-error toward a best-compromise skyloop.
4. • Transfer your arbitrary polygon vertices to an NEC variant for much improved accuracy.

Download     ←   ↑   → 

You’ll need two things for it to run: my *.exe application itself, plus also the interpreter program on which it runs. Kind of like Java that way, except that the Java interpreter is probably pre-installed on your system. The LabVIEW run-time engine will not be.

1. Download 1st:  LabVIEW Runtime Engine 
   • This is the interpretor program.
   • Or, should it please you, the entire LabVIEW programming environment.
   • Link back to ky8d.net/free where I give download instructions.
2. Download 2nd:   ZIP  
3. Important! Best to employ a stand-alone ZIP archive software (like  7-Zip ) for extracting the *.exe file. Otherwise, Windows will issue dire warnings of an unrecognized app. Once extracted from out of its archive, however, Windows will know to pass it off to the LabVIEW Run-Time Engine instead.
4. Source Code, for any who want it.
   • Do with my LabVIEW code just as you please. Credit me or not as you choose. Do please pass along any credit I’ve given to other sources.
   •  Source  The LabVIEW source code.

Caveat Mutuum     ←   ↑ 

Latin for “Let the moocher beware”. I designed this for me, and used it with glee. I share it here with you for free, but offered without even so much as the smell of a dead warrantee (or wheriot, as the case may be). Whatsoever disasters of cosmic proportion as may result from the use of this program, any and all culpability rests wholly and solely with the user.