NEC Segs Calculate non-redundent segmentation of NEC files. NEC, segs, segmentation, AN-SOF, Perl Gan Uesli Starling 2024, Gan Uesli Starling NEC Segmentation

A free, open-source tool for calculating non-redundant values of segs/wavelength.

home: ky8d.net/free

Introduction

In re-segmenting an AN-SOF or NEC model, small changes occasionally clone an exactly identical file. Take, for instance, the model below, segmented at 13 and 18 segments-per-wavelength for 5.332 MHz.

13 segs/WL 18 segs/WL

They are exactly identical! The same would occur were I to have segmented it at 14, 15, 16, or 17 segs/WL. Not until 19 segs/WL will the above model change at all for 5.332 MHz.

Herewith I provide a means to avoid wasteful trial-and-error by discovering beforehand which segmentations produce unique models. One then may proceed to explore model convergence in an efficient manner.

Usage Screenshot

My free, open-source program works on both Windows and Linux like so.

On Windows
  • Copy the file KY8D_NEC_Segs.exe into any directory containing one or more *.nec files
  • Double-click the starling icon for KY8D_NEC_Segs.exe.
  • Within the pop-up CLI window, enter segmentation frequencies one per line.
  • Enter nothing when done.
  • Open the file ./segs_per_wavelength.txt
 On Linux
  • Copy the script KY8D_NEC_Segs.pl into any directory containing one or more *.nec files
  • CD into that same directory.
  • Enter perl KY8D_NEC_Segs.pl.
  • Enter segmentation frequencies one per line.
  • Enter nothing when done.
  • Open the file ./segs_per_wavelength.txt
 Units of Measure

In NEC decks, it is strangely allowed for plural GS (Geometry Scaling) cards to be present. Almost never does anyone do this, as it would exert a cascade effect. Each succeeding GS card would then re-scale all prior scalings before it. My program therefore anticipates no more than a single GS card to be present, if any. If plural are found, all but the final will be ignored, with it alone exerting universal effect. This ought to be no problem at all.

 The Example

A 5.6m vertical can indeed be used at 5.332 MHz. I employ just such a vertical in conjunction with an LDG RT-100 remote auto-tuner for portable work. This real-world antenna easily covers 10m through 60m, WARC included.

Link: Camera Tripod Vertical
Sample Output

Below is an example output file. Shown is the result of running KY8D_NEC_Segs.exe in a directory containing a single *.NEC file. Had there been plural files, all would have been parsed.

Non-redundant segments-per-wavelength.

File = 36-radial_vert.nec
GW lines tally = 74
Unique lengths (m): 0.100, 5.500, 2.460, 8.888

Freq = 5.332 MHz
Segs/wire @ 10/wl: 1, 1, 1, 2
Segs/wire @ 11/wl: 1, 2, 1, 2
Segs/wire @ 13/wl: 1, 2, 1, 3
Segs/wire @ 19/wl: 1, 2, 1, 4
Segs/wire @ 21/wl: 1, 3, 1, 4
Segs/wire @ 23/wl: 1, 3, 2, 4
Segs/wire @ 26/wl: 1, 3, 2, 5
Segs/wire @ 31/wl: 1, 4, 2, 5
Segs/wire @ 32/wl: 1, 4, 2, 6
Segs/wire @ 38/wl: 1, 4, 2, 7
Segs/wire @ 41/wl: 1, 5, 2, 7
Segs/wire @ 45/wl: 1, 5, 2, 8
Segs/wire @ 46/wl: 1, 5, 3, 8
Segs/wire @ 51/wl: 1, 5, 3, 9
Non-redundant segs: 10, 11, 13, 19, 21, 23, 26, 31, 32, 38, 41, 45, 46, 51

Freq = 7.035 MHz
Segs/wire @ 10/wl: 1, 2, 1, 3
Segs/wire @ 15/wl: 1, 2, 1, 4
Segs/wire @ 16/wl: 1, 3, 1, 4
Segs/wire @ 18/wl: 1, 3, 2, 4
Segs/wire @ 20/wl: 1, 3, 2, 5
Segs/wire @ 24/wl: 1, 4, 2, 6
Segs/wire @ 29/wl: 1, 4, 2, 7
Segs/wire @ 31/wl: 1, 5, 2, 7
Segs/wire @ 34/wl: 1, 5, 2, 8
Segs/wire @ 35/wl: 1, 5, 3, 8
Segs/wire @ 39/wl: 1, 6, 3, 9
Segs/wire @ 44/wl: 1, 6, 3, 10
Segs/wire @ 47/wl: 1, 7, 3, 10
Segs/wire @ 48/wl: 1, 7, 3, 11
Segs/wire @ 52/wl: 1, 7, 4, 11
Non-redundant segs: 10, 15, 16, 18, 20, 24, 29, 31, 34, 35, 39, 44, 47, 48, 52

Freq = 10.125 MHz
Segs/wire @ 10/wl: 1, 2, 1, 4
Segs/wire @ 11/wl: 1, 3, 1, 4
Segs/wire @ 13/wl: 1, 3, 2, 4
Segs/wire @ 14/wl: 1, 3, 2, 5
Segs/wire @ 17/wl: 1, 4, 2, 6
Segs/wire @ 20/wl: 1, 4, 2, 7
Segs/wire @ 22/wl: 1, 5, 2, 7
Segs/wire @ 24/wl: 1, 5, 2, 8
Segs/wire @ 25/wl: 1, 5, 3, 8
Segs/wire @ 27/wl: 1, 6, 3, 9
Segs/wire @ 30/wl: 1, 6, 3, 10
Segs/wire @ 33/wl: 1, 7, 3, 10
Segs/wire @ 34/wl: 1, 7, 3, 11
Segs/wire @ 37/wl: 1, 7, 4, 12
Segs/wire @ 38/wl: 1, 8, 4, 12
Segs/wire @ 40/wl: 1, 8, 4, 13
Segs/wire @ 44/wl: 1, 9, 4, 14
Segs/wire @ 47/wl: 1, 9, 4, 15
Segs/wire @ 49/wl: 1, 10, 5, 15
Segs/wire @ 50/wl: 1, 10, 5, 16
Non-redundant segs: 10, 11, 13, 14, 17, 20, 22, 24, 25, 27, 30, 33, 34, 37, 38, 40, 44, 47, 49, 50
Download

Version 2025-01-03 an update to disallow segment length < 3 wire diameters

  1. KY8D_NEC_Segs.zip
  2. Unzips into two files: an *.exe for Windows; and also the *.pl source code.
  3. Best to employ a stand-alone ZIP archive software (like 7-Zip) for the extraction.
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.