The plotting of current and patterns were designed to be rather straight 
forward.  The package can handle up to about 160 unknowns in DOS.

program and documentation provided by author Dr. William A. Davis <wadavis@vt.edu>

Notice: Several users have reported problems with nec2d_me and
nec2d_lapack. These problems were related to inaccurate results
when the NE card was in the input deck and software crashes when
an LD (load) card was present. The author's e-mail address appears
to be no longer active.

A Win32 executable targeted to the PentiumPro or later IA 32 machine and using allocatable arrays so that one program handles all structure geometry sizes. The folder also has a SOMNEC executable and the modified source code (Fortran 90).

contributed by Joe Lastovka  (joe_lastovka@yahoo.com)

Notice: Several users have reported problems with nec2d_me and
nec2d_lapack. These problems were related to inaccurate results
when the NE card was in the input deck and software crashes when
an LD (load) card was present. The author's e-mail address appears
to be no longer active.

Same as NEC2D_Me except that it uses the Intel MKL LAPACK routines to factor and solve the NEC matrix equations. Pentium III only. About 20 times faster on matrix factor and solve at large matrix sizes.

contributed by Joe Lastovka  (joe_lastovka@yahoo.com)

contributed by Joe Lastovka  (joe_lastovka@yahoo.com)

contributed by Joe Lastovka  (joe_lastovka@yahoo.com)

from Barry Newberger (bsn@fusion.ph.utexas.edu)

from Barry Newberger (bsn@fusion.ph.utexas.edu)

This binary was produced on a Power Macintosh G4/400 running OS X Public Beta

This binary was compiled from the NEC2 C source. The C source was obtained from
Raymond Anderson's Unofficial Numerical Electromagnetic Code (NEC) Achive.
(http://www.qsl.net/wb6tpu/swindex.html). The source was originally from the
ucsd.edu archives, and was converted from FORTRAN to C using f2c, according to
the Unofficial Archives.

Some modifications to the original Makefile and sources were necessary for the
sources to compile. I could not get the sources to compile using the supplied
f2c.h headers, so the f2c library from Bell Labs (netlib.bell-labs.com) was
installed and linked to produce the final binary. Typographical errors in the
Makefile and some sources which prevented compilation and linking were also
corrected.

The gzipped tar file contains the executable, a README file, diffs to document source  changes and several example input files.

contributed by Derwood Eadie (KG4EFO@arrl.net) 21 Nov. 2000

This version of NEC2 uses 32 bit reals and compiles well with
Microsoft Fortran for Powerstations. I obtained it from
ftp.ucsd.edu /hamradio/NEC and have added the subroutine SECNDS
for PC:s. The NEC-code at that site contained a nasty bug in a
Hollerith string that is corrected. The subroutine ENF is commented
away since it is not needed on PC:s. A declaration that changed a 
common area is also corrected. The resulting executable has
been checked against a few testcases and seems to give correct
results. The original notes and doc files is not changed.

SM5IUF /Gunnar Isaksson
gunis@weald.air.saab.se
 

Name of    Max number  Approximate  
executable of segm.    memory use (MB) 
- - - - - - - - - - - - - - - - - - - - - - 
NEC2D.EXE       256        1.5 (*)
NEC2D512.EXE    512        5 
NEC2D960.EXE    960       16 
NEC2D1k4.EXE   1392       32 

(updated 1/22/96) from Jozef Bergervoet (bergervo@prl.philips.nl)

Description of the NEC2D files: --------------------------------------------------------------------------

EXAMPLE.DAT is an input file with several examples. These can be tested in one single run by giving this file as input.

NEC2D***.EXE Several working version of the NEC program. Differences:

 
Name of      Max number   Approximate
executable   of segm.     memory use (MB)

    - - - - - - - - - - - - - - - - - - - - - -
             /    NEC2D.EXE        256         1.5 (*)
 These are  |     NEC2D512.EXE     512         5 
 found in   |     NEC2D960.EXE     960        16 
 nec-pc.zip |     NEC2D1K4.EXE    1392        32 
             \    NEC2D1K9.EXE    1950        60 
             /    NEC2D2K8.EXE    2800       122 
These files |     NEC2D4K.EXE     4000       247 
  are in    |     NEC2D5K7.EXE    5700       500 
nec-pc-x.zip|     NEC2D8K1.EXE    8100      1006
             \    NEC2D11K.EXE   11000      1852

*.FOR, *.INC Files containing the Fortran source code. In nec-pc-x.zip --------------------------------------------------------------------------

Jos Bergervoet, bergervo@natlab.research.philips.nl bergervo@iaehv.nl

nec2sx

Fortran 77 source code of single-precision NEC2 modified with  FACTR and SOLVE routines modified to support non-transposed matrices for faster runtime performance. File nec2sx.tar contains the Fortran source code and simple compilation directions.

File nec2sx is a compiled SUN Solaris executable that also includes support for multithreaded execution. See the documentation in the source code tar file for setting up the multithreaded environment variable. This executable is compiled to support 1500 segments. Compiled on Solaris 2.5.1, also tested on Solaris 7 and 8
 
 

contributed by Ray Anderson WB6TPU  <raymond.anderson@sun.com>

nec2dx

Fortran 77 source code of  double-precision NEC2 modified with  FACTR and SOLVE routines modified to support non-transposed matrices for faster runtime performance. File nec2dx.tar contains the Fortran source code and simple compilation directions.

File nec2dx is a compiled SUN Solaris executable that also includes support for multithreaded execution. See the documentation in the source code tar file for setting up the multithreaded environment variable. This executable is compiled to support 1500 segments. Compiled on Solaris 2.5.1, also tested on Solaris 7 and 8

contributed by Ray Anderson WB6TPU  <raymond.anderson@sun.com>

nec81.zip

YGO2 is a FREEWARE progarm. It may be freely copied and distributed, but ONLY as long as there is no cost to the recipient.

Unlike the original release of YGO, this version allows the user to optimize the array at up to 15 different frequencies, and to specify a different driven element (if desired) at each frequency. Unexcited DEs are assumed to be terminated in the feed system characteristic imped- ance.

YGO2 (YAGI GENETIC OPTIMIZER II) designs optimized Yagi antennas using one of the most recent and powerful techniques in applied electro- magnetics: a genetic algorithm. A genetic algorithm mimics natural sel- ection ("survival of the fittest") by creating generations of Yagi designs in which the best designs ("individuals") pass their design parameters ("genes") onto the next generation in such a way that better and better antennas are the result. GA optimizers can produce remarkable results not achievable with any other design technique. Genetic algorithms are superior to deterministic optimzers, and they are easily implemented on a PC.

YGO2 is user-friendly and easy to run. All GA parameters are changed by editing a single set-up file. The user can specify popu- lation size, number of generations, antenna figure-of-merit, and all other parameters needed by the GA. The Yagi's performance is computed using NEC-2D, the state-of-the-art Numerical Electromagnetics Code (double precision) developed at Lawrence Livermore National Laboratory.

When YGO2 has completed its optimization, the radiation pattern of the best antenna is plotted on screen. A separate plotting utility allows the user to view radiation patterns for other top designs on a generation- by-generation basis. One of the GA's most attractive features is that, instead of producing only one "best" design, it produces groups of designs that achieve similar performance. The designer can then select from these groups the Yagi that best meets the requirements.

To install YGO2, copy the file INSTYGO2.EXE into the directory on your hard drive that you will use for YGO2. YGO2 files are created by executing  INSTYGO2.EXE, which is a self-extracting EXE file. If you have a previous version of YGO2, simply overwrite all files of the same name.

Be sure to check the README.TXT and YAGI_GA.TXT files for inform- ation on setting up a YGO2 run. The file NEC2INFO.TXT contains information on creating various size NEC-2D executables. Any changes to YGO2 will be described in the file UPDATE.TXT. Please read UPDATE.TXT if it is present.

YGO2 is a DOS program that must be run under MS or PC DOS (ver.3.3 or higher), Compaq DOS (ver.3.31 or higher), or in a DOS window under MS Windows 3.0 or higher. YGO2 also requires an 80386/87 math coprocessor or higher CPU and about 1 MB of RAM (depending on the model size).

Contributed by Phadean Engineering <phadean@ieee.org> PO Box 611, Shrewsbury, MA 01545-8611 USA, tel. (508) >869-6077, fax (508) 869-2185)

 YGO3 (Yagi Genetic Optimizer, Ver. 3) is a real-valued genetic
algorithm (GA) that designs optimized Yagi-Uda arrays by maximizing a
user-specified figure-of-merit (FoM).  Antenna designs created by YGO3 
are modeled by NEC-2D (Numerical Electromagnetics Code, Ver. 2, double
precision), a recognized standard for modeling wire antennas developed
at Lawrence Livermore National Laboratory.  YGO3 handles up to 150 ele-
ment arrays at up to 50 frequencies.  The GA includes state-of-the-art
techniques such as quadratic interpolation, auto-grooming, coefficient
perturbation, coefficient activation, several selection methods, and two 
crossover methods.  YGO3 is a DOS program which may be run in a DOS win-
dow under the Windows operating system.

 YGO3 is a FREEWARE program.  It may be copied and distributed
without restriction as long as there is no cost or charge of any kind,
including "tie-in" costs, to the recipient.  YGO3 has been developed and
is distributed as a service to the amateur radio community.  Please email
comments, suggestions, or questions to: ygo3@yahoo.com.

 YGO3 is installed by executing the self-extracting file
YGO3INST.EXE in the default directory, usually C:\YGO3.  All necessary
files are created, including several versions of NEC-2D that allow for
models with 28 to 1500 segments.  Please read the file YGO3_MAN.TXT for
setup and operating instructions.

 YGO3 is the successor program to YGO2, a binary-coded genetic
algorithm for optimizing Yagi arrays.  Because YGO3 includes several
improvements, designers using YGO2 should upgrade to the newer real-valued
GA.

Contributed by Phadean Engineering <phadean@ieee.org> PO Box 611, Shrewsbury, MA 01545-8611 USA, tel. (508) >869-6077, fax (508) 869-2185

(download both the
version 4.2 zip file
and the supplementary
zip file)

A Windows utility that facilitates the generation of NEC source decks and viewing of the resultant output.

***
4nec2 features:

- Display and validate antenna structure for nec-2 input- and output-file
- Display and check the current/phase distribution along your antenna.
- Display linear or logarithmic 2D and 3D far field pattern
- Display 3D, 2D or graph plots for the near electric and magnetic field
- Display impedance, SWR and gain graphs with frequency loop
- Display horizontal or vertical far field with frequency loop
- Display impedances, SWR and calculate feedlines and losses on Smith-chart
- Generate ItsHF type-13 (area coverage) or -14 (point to point) ant-files.
- Automatic generation of sommerfeld/norton ground files
- Automatic generation of far/near field-, frequency loop- and ItsHF data.

***

Additional features added in version 4.0:
***************

- Depending on the computers RAM capacity, model up to 11000 segments
- Increase antenna performance by Optimizing antenna/geometry settings
- Display linear or logarithmic 2D and 3D pattern for near- or far-field
- Display and validate antenna structure and currents for nec-2
   in/output-files
- Display impedance(smith-chart), SWR or gain graphs and far-field with
   frequency loop
- Generate ItsHF type-13 (area coverage) or -14 (point to point) antenna
   files.

****************
Changes with version 4.1:

- Increased optimizer functionallity
- Bugs removed, some problems solved
- Geometry builder added
****************

Changes with version 4.2:

- Special 'wysiwyg' nec2 based editor.
- Support for GM, GR an GC cards.
- Power en SWR info on selected segments.
- Enhanced zoom/rotate and current display.
- Keep and restore window settings.

*) See ReadMeFirst.txt for installation notes
***********************
 
 
 

Contributed by the author Arie,  <4nec2@gmx.net> Neede, The Netherlands]

from Roy Lewallen W7EL 

(contributed by the author Roger Cox WB0DGF) <Roger.Cox@telex.com>

necpost2.bas is Nec-post-processor 2.1 developed by Agostino Rolando . The original file was necpostproc.bas by J. Boyer. 

I have taken Necpostproc.bas and nov.bas and mixed them together to display 2d - 3d radiation patterns and current distribution along the antenna .

It works better with vertical radiators.

This 2.1 version has eliminated some little bugs of earlier 2.0 .

Note that ,in order to draw a true 3d radiation pattern, the antenna must be arranged as to have the feed point just in (0,0,0) coordinates.

For yagi design, I found a good agreement with yagimax 3.0 program by Lew Gordon.

Here you find : 

nec2pc.exe - nec2 for pc. Requires 486dx or better and as much memory as the number of segments you use for antenna's description.

niv.exe - nec input viewer. Shows input structure descriptor files *.nec. You can evidentiate errors in designing your antenna before nec2pc processing.

nov.exe - nec output viewer . Shows the distribution of currents along the antenna (*.out files).

necpost2.exe - nec postprocessor . Shows radiation patterns and current distrib. for *.out files.

A few sources examples are included.

NOTE : To know how to compile input descriptor files, see Nec User's Guide in http://www.traveller.com/~richesop/nec/ , available in pdf format.

Have a good work !

Agostino Rolando E-mail: rolago@iname.com

This utility (nec.exe) runs from the command shell (DOS prompt) and opens a NEC input file and determines if the Sommerfeld ground is used and obtains the frequency, K and sigma terms so it can locate or generate the appropriate SOMNEC interpolation grid before invoking one of the variants of NEC2D. This SOMNEC data is stored for future use; the user can specify the location of this data by setting the SOMNEC environment variable. 

NEC.EXE also determines the appropriate variant of NEC2D based on the number of in-core segments. The program requires nec2d512.exe, nec2d960.exe, nec2d1k4.exe, and RTM.EXE in the current directory or the PATH environment variable.

Source code included (The program could also be recompiled on Unix afer some modifications.) 

*** NOTE: If you downloaded this prior to 12/29/98 and are experiencing problems, download the new version now online which has been modified to include some missing library files.

***UPDATED 2/26/02
(contibuted by the author Ralph Holland , VK1BRH <ralph@arising.com.au> 
< http://www.arising.com.au/people/Holland/Ralph/index.htm >

It allows:

* To run nec2 passing the name of the file .nec 

* To visualize in X-windows radiation diagrams of antennas, 

* To display the main results as Gain, F/B, Z etc. 

* To produce Post Script files to be printed

Requirements:

Npp reqires yorick 1.4. (available from ftp://ftp-icf.llnl.gov/pub/Yorick/)

If you wish recompile nec2 you need yaf77-1.3

(provided by Pino Zollo I2KFX <pinoz@highway.com.py>)

(contributed by Alexandre Kampouris)

(contributed by Alexandre Kampouris)

(from Unofficial NEC Home page  ttp://members.home.net/nec2/)

Good Luck on your antenna designs- Clyde Edgar WA6DCM 

from Clyde Edgar WA6DCM <Edgar@courier1.aero.org> 

Glenn Stumpff
gstumpff@yahoo.com

(unofficial NEC home Page) also maintains links to other NEC resources

contributed by George Christianson <gchristianson@pppl.gov> 

contributed by George Christianson <gchristianson@pppl.gov> 

contributed by the author  Patrick Wintheiser  W0OPW  <w0opw@yahoo.com>

from Dr. D.B. Davidson (davidson@firga.sun.ac.za ) 

WireGrid for Windows (version 2.11) is the second release of this NEC pre-processor. WireGrid was developed by EM Software & Systems in collaboration with the University of Stellenbosch.

(Note: the version on the this ftp site is enabled in the DEMO mode. It is fully functional but limited to 15 elements.)

from Dr. F.J.C. Meyer (fjcmeyer@emss.co.za )

This is a suite of programs written in BLT - an extension of TCL/TK - which are intended to assist in visualizing antennas. The package is intended to provide windows which show both antenna patterns and antenna configuration. An accompanying article in both LaTeX and PostScript form describes the process of designing a simple antenna using the system.

The suite has been built under SCO 5.0.2 and SCO 5.0.4 (Free SCO), but should run under any system that can make the blt extension of tcl/tk work. (That should be the majority of systems on the planet.)

(contributed by Bill Walker W5GFE , <bw@cs.ecok.edu >

 SYNOPSIS

  Necview
  Azimuth  [filename]
  Elevation [filename]
  Wires

 DESCRIPTION

These programs are written in Perl/Tk (version 5.005_2),
and provide tools which can help to visualize antennas or analyze data 
which is produced by NEC2 - the antenna modeling program.

The NEC2 program is commonly used by radio amateurs or professional
antenna designers on Unix equipment to model antennas.  While NEC2 is quite 
versatile, the output of NEC2 is voluminous and difficult to read.  This suite of programs
provides graphical depictions of NEC2 output.

Azimuth provides three graphs of "horizontal"
radiation patterns:  an ARRL-scaled polar
plot, a linearly scaled polar plot, and a cartesian plot.  A "fact box"
provides indication of -3 DB beam widths.

Elevation provides similar information for vertical radiation
patterns.

Wires is a visualization tool which shows three views of the same
antenna.  Views are provided for the "XY plane", the "YZ plane" and
the "XZ plane".

Necview borrows heavily from the "xnecview" program by
P.T. de Boer (pa3fwm@amsat.org). 
 
 

Sample data files are included in each subdirectory.

The W5GFE Antenna Toolkit is released
under terms of the GNU Public License.
 
 

 AUTHOR

Bill Walker, W5GFE, bw@cs.ecok.edu

NEC.XLS 

Updated version VB1.10 (1/12/99) now online.

NEC.XLS contains pages to handle the following topics: 

 1 INTRO 
 2 DECKMAKER 
 3 VIEWER 
 4 AUTO NEC 
 5 DISPLAY 
 6 ANALYSER 
 7 DIPOLE 4 STACK 
 8 DIPOLE 4 STACK(2) 
 9 FOLDED STACK 
 10 ROTATABLE FLATSTACK 
 11 TILTED DIPOLE 
 12 HELIX and MICRO LOOP 
 13 TAPERED HELIX and MICRO RING 
 14 ANTIPHASED HELIXES 
 15 LPDA 
 16 LPV  1 
 17 LPV  2 
 18 DISCONE 
 19 BIFILAR 
 20 SLOTTED RING 
 21 FOLDED DIPOLE 
 22 FRANKLIN 
 23 VERTICAL FRANKLIN 
 24 LAZY - H 
 25 PARABOLIC YAGI 
 26 DIPOLE withPARABOLIC REFL. 
 27 YAGI MAKER 1 
 28 YAGI MAKER 2 
 29 LAUNCHER 
 30 CORNER REFLECTOR 
 31 STANDARD GAIN 
 32 DECK FILE INDEX 
  REVISION HISTORY 
 

AN ANTENNA MODELLING PROGRAM, INTEGRATING THE CONVENIENCE of EXCEL with the POWER of NEC 2 ...for experienced EXCEL users, with access to adequate computing power.

Release 1.07A ,1/7/98. This version, released privately, has a restricted number of prepared antenna design sheets. The Workbook is not locked, with the intention that users may add their own antenna design sheets. No charge is made, nor any responsibility accepted .

WHAT NEC.XLS DOES The series of sheets in NEC.XLS allow you to automate most of the common tasks associated with using a NEC 2 engine for modelling antennas, and tabulating the results. This program automates your entire antenna assessment. It will step through up to three design variables at a time , with increments as selected. Having incremented chosen variables, a NEC INPUT DECK is automatically built. This is fed to a NEC 2 engine automatically. The Output file from the NEC engine is then read by EXCEL, and a summary of gain, F/B, and antenna input impedance is produced. If desired, a Thumbnail plot for each design is produced. Finally, a table of results is available, which is sorted by a Figure of Merit based on your weightings. The program thus loops away, building and summarising design changes within your set parameters.

(contributed by the author Peter Ward <pward@net-tech.com.au> Bairnsdale, Victoria, Australia )

RF2.zip

RF1.xls, and RF2.xls (Release 4.12, 04/9/2001) 
 These workbooks form a practical companion to the automated NEC design package, which is available on this site as XLNEC.ZIP (and which is unchanged except for the readme file now included in Microsoft Word format)
Both RF1 and RF2 have much added material, and a Readme with expanded detail of content. In particular, a little more help re. correcting problems with Excel's losing track of its macros.
  Every page in these workbooks was put together to assist in solving a real day-to-day problem in a workshop dealing with antenna design and construction. They contain practical modules for solving every formula-related RF problem the author has encountered.
In particular, there are sheets that will help de-mystify these topics, and more!
    ANTENNA GAIN CALCULATIONS
    PATH BUDGETS
    STUB CALCULATION and PLACEMENT
    PHASE TILT
    VSWR CALCS
    BUILD MMIC IN-LINE AMPS .. that replicate the gain curves in the HP app notes.
    BUILD BROADBAND DIRECTIONAL COUPLERS good to 1 gHz, for $20
    IMPEDANCE MATCHING
    POWER DIVIDERS
    SLOTTED LINES
    PATTERN TILT on COLINEARS
    SLUG TRANSFORMERS/MATCHERS
    IMPEDANCE CHARTING
    MATCHING with IMPEDANCE CHARTS
    CABLE LOSS CALCULATION for ANY CABLE
    RETURN LOSS UNCERTAINTY
    INDUCTOR and OP-AMP CALCS
    RSSI CALIBRATION CURVES as a basis for ACCURATE RF MEASUREMENTS
... and a couple of ring-ins. CYLINDER HEAD FLOWBENCH may interest some
 The books contain macros. To relieve the fainthearted, they are verified against the latest PC-Cillin Signatures, and directly uploaded ONLY to the 'Unofficial NEC Archives' for your protection. The macro pages are unlocked, and I encourage modification and suggestion for improvement.
 Please pay attention to README.RTF, which gives instruction for the correct setting up of Excel, and has been a matter of some frustration to many!
 The material is offered freely to the users of 'The Unofficial Nec Archives' as an encouragement to those of you whose RF experience goes beyond just buying the 'latest and greatest'. It is my contribution to helping 'keep the dream alive'! 
  From the workshop of 
                    Peter Ward, AX2VCI.  Bairnsdale, Victoria, Australia
                    pward@net-tech.com.au
 

(contributed by the author Pieter-Tjerk de Boer PA3FWM pa3fwm@amsat.org or ptdeboer@cs.utwente.nl)

The materials contained in this directory may be of some use to the
amateur community.  They also represent a remarkable work of love
and devotion on the part of XYL Ursel Kreh, wife to
Hartmut Hans Kreh DL5SAY, who died in January 2001, aged 54.

I offer them, through the courtesy of Frau Kreh, to the Amateur
Community.  Please direct any correspondence to:

        Bill Walker W5GFE
        bw@cs.ecok.edu

        Professor and Chairman
        Department of Computer Science
        East Central University
        Ada, Oklahoma