For the EZNEC/EZNEC+ v. 4.0 FAQ, please click here.

I'm having trouble installing or running the program on a new computer.

See Using Older Versions.

My program wasworking, but now it fails with the message 'Runtime error 339:Component dwsbc36.ocx or one of its dependencies not correctlyregistered, a file is missing or invalid'.

Several spyware removal programsincorrectly identify dwspy36.dll, a file used by dwsbc36.ocx, asspyware and recommend its deletion. (See "What isdwspy36.dll in theEZNECprogram directory", below, for information about these files.) The messageoccurs when the file isdeleted. Restoring EZNECfunctionality requires restoring dwspy36.dll. Some spyware removalprograms allow this, or it might be restored with an undelete utility.If neither is possible, running the EZNECinstallation will recreate the file. The current version of EZNEC nolonger uses these files, but v. 3.0 does. So version 3.0 users shoulddirect any spyware removal programs to not delete them.

When I try to installEZNEC I get the message 'C:\WINDOWS\SYSTEM32\AUTOEXEC.NT. The systemfile is not suitable for running MS-DOS and Microsoft Windowsapplications' or other message involving AUTOEXEC.NT.

This is most often caused by the Windows XPServicePack 2 (SP2) installation deleting (for unknown reasons) theAutoexec.nt file which is required to run 16 bit programs. The EZNECinstallation program is intentionally an older type in order to keepdownload size smaller and updates simpler, and requires 16 bit(DOS-type) operation during part of the process. (EZNECitselfdoesn't.) You should be able to solve the problem by locating a copy ofAutoexec.nt in your C:\Windows\Repair directory (the directory might beC:\Winnt\Repair on systems upgraded from Windows 2000) and copying itinto your Windows system directory C:\Windows\System32 (orC:\Winnt\System on some upgraded systems). If you need furtherassistance orthis doesn't fix the problem, please let meknow.

Will EZNEC3.0 rununder Windows XP? Vista? Windows 7?

Yesto all, but not 64 bitversions of those operating systems. EZNEC prov. 3.0requires some modification to run under Vista or Windows 7. EZNEC prousersshould contact mefor additionalinformation. No EZNECv. 3.0 program type will not install on 64 bit operating systems. Seenext item.

Will EZNEC3.0 rununder 64 bit operating systems?

No.If you have a 64 bitoperating system (such as the 64 bit versions of XP, Vista, or Windows 7), you mustupgrade to the current version of EZNEC or request a refund. There is no problem running EZNEC v. 3.0 ona 64 bit computer, as long as the operating system is 32 bit. Exceptfor versions specifically identified as 64 bit, Windows XP and Vistaare 32 bit systems.

Can EZNEC 3.0use theantenna description files I created with an earlier version?

Absolutely!EZNEC 3.0can even read and translate ELNEC (.EN) files -- just include theextension (.EN) when specifying the name of the file to open. Olderversions of EZNEC can also readand use files written byEZNEC3.0. EZNEC 3.0uses the same plot file format asEZNECv. 2.0, and can display plots saved by ELNEC or any version of EZNEC.

If I buy the CD-ROMversion, does the CD-ROM have to be in place when running the program?

No.All necessary files areinstalled on your hard drive. The CD-ROM is needed only forinstallation. If desired, the CD-ROM files can be copied to a harddrive or Zip drive and the program installed or re-installed from there.

Where's the manual?

The manual is anintegral part of the program. With EZNEC3.0 running, In the EZNEC 3.0Control Center(themain window), click Help on the menu bar, then choose Contents to viewthe manual. You can also open the manual to the relevant topic frommanyplaces in the program by pressing F1. This sort of manual is oftencalled an "on-line" manual, but people sometimes mistakenlymisinterpretthat term to mean that the manual is on the Internet. It's not.

Is it possible to geta printed manual?

A version is now available whichyou can load into aword processor and print yourself. If you purchased EZNEC3.0on a CD-ROM after about September 1, 2000, you'll find it in thePrintable Manual directory on the CD-ROM. Otherwise, you can downloadit. Clicking herewill takeyou to the page where you can get more information. No printed manualisavailable.

What's the EZNEC 3.0segment limit?

Thelimit for EZNEC 3.0is the same as for earlier versions, 500 segments maximum. This allowsapproximately 25 wavelengths of wire, or 50 beam elements. Theprofessional versions of EZNEC 3.0accommodate up to10,000 segments.

Will EZNEC 3.0overwrite my ELNEC or DOS EZNEC program?

No. EZNEC 3.0will not affect theseprograms in any way. You can even install it in the same directory ifdesired.

What's the differencebetween the upgrade version and full program?

There are no different"upgrade" and "full" or "new"versions. There's only one version, and it's a complete, independentprogram which doesn't require any other program in order to function.The only difference between a new purchase and an upgrade purchase isthe price; the program is the same.

Is there anydifference between the download and CD-ROM products?

The installed programis exactly the same -- theonly difference is in the format of the files used for installation.Thedownload product is a single executable file, for convenientdownloading. It expands and creates temporary files during theinstallation process, which are deleted when the installation iscomplete. The CD-ROM contains several files. Although it also createssome temporary files during installation, they aren't as large as theones created by the download version. Consequently, the downloadproductrequires somewhat more disk space (roughly 15 MB) during installationthan the CD-ROM product. Otherwise, there's no difference. Onceinstalled, the programs and disk space requirements are the same. Youmay need to re-install EZNECin theevent of a hard drive failure orchange to your computer system, so you should always keep either theCD-ROM or downloaded file. If you don't have any way to back up thedownloaded file on some medium other than your primary hard drive, youshould order the CD-ROM (with or without the download) to protectagainst loss of the program in the event of a hard drive failure.

Doesn't being aWindows program make EZNEC 3.0 slower than the older DOS versions?

Actually, EZNEC3.0 does itscalculations about 20% faster than previousversions. Thecalculating engine is a separate FORTRAN executable file which doesn'tmake any Windows calls (except to communicate calculation progress tothe main program), and the FORTRAN compiler used for the EZNEC3.0 calculating engine has better optimization thanthe oneused for previous versions. All other operations, such as graphics, areas fast or faster than earlier versions. One of the slowest operationsin DOS EZNECwas calculation of wire connections each time a wirecoordinate was changed. This process has been optimized and moved to aFORTRAN DLL, and runs something like 20 timesfaster thanbefore. If you do experience very slow operation of EZNEC3.0,please see the next item.

My EZNEC 3.0 runsextremely slowly. Why?

Some versions of McAfee Antivirus sofware,when runningin the background detection mode, can cause extremely slow operation ofEZNEC3.0 calculations. This problem can suddenly appearwhen theantivirus software is updated. Apparently, the antivirus softwareintercepts and analyzes the communications between the calculatingengine and the main program. These communications are numerous andfrequent, so the rather slow analysis process by the antivirus programgreatly slows EZNECoperation. The only certain solution is to disablethe background checking feature of the McAfee software while runningEZNEC 3.0. So far, thishas been reported only with McAfee version 4, and it appears thatversion 6 might not have this effect on EZNEC.Thisisn't certain,however.

What isdwspy36.dllin the EZNEC program directory?

Some people have expressedconcern about dwspy36.dlland wonder what its function is. This file is a "subclassing" control,part of a third-party utility package called SpyWorks, purchased fromDesaware, a highly respected company which is well known to the VisualBasic programming community. This package allows functionality beyondthat provided by Visual Basic or normal Windows programming but despiteits rather sinister name is not "spy" software. When you attempt toreduce the size of graphical windows below a certain point, EZNEClimitsthe minimum size. This size limiting isn't possible with Visual Basic(except with "bounce-back" type operation), so a technique called"subclassing" is used. EZNECinterceptsthe normal Windows message sentwhen a window is resized and directs it to code that limits the windowsize. The SpyWorks control (dwsbc36.ocx, which uses dwspy36.dll) allowsthis functionality. (It'sapparently so namedbecause of its ability to "spy on" -- intercept -- messagessent to and from the Windows operating system by applications duringnormal operation.) Some versions of EZNECinstalleddwsbc36.ocx and dwspy36.dll in the EZNECprogram directory; other versions installed them in the Windows systemdirectory instead. An increasing number of spyware removal programsmisidentify dwspy36.dll as spyware and delete it, which caused EZNECto crash.Because of this problem, EZNECwas modified at version 4.0.5 to use a recompiled version of a similarDesaWare product, rather than dwsbc36.ocx and dwspy36.dll. V. 4.0.9 andlater use an entirely different and newly compiled control. Version 3.0continues to use the DesaWare files, so version 3.0 users should directanyspyware removal programs to not delete them.
No versionofEZNECdoeskeystroke logging or any other type of user activityrecording, reporting, or Internet connection. For more informationabout the SpyWorks package, seehttp://www.desaware.com/SpyWorksL2.htm, and for more information aboutsubclassing, see http://www.desaware.com/Subclassing.htm.

What languageisEZNEC 3.0 written in?

The interface portion of theprogram was written inMicrosoft Visual Basic 6.0. It consists of about 50,000 lines of sourcecode, not counting comments. I wrote every line, and it took about twoyears of essentially full time work to develop the Windows version. Thecalculating engine is a modified version of the public domain NEC-2program. It's written in Fortran, and incorporated as a separateexecutable file.

Where can I get moreEZNEC models?

The CD included with the 20th and later editions ofthe ARRL Antenna Bookhas severalhundred EZNECmodels of a wide variety of antennas. While specially created to workwith the EZNEC ARRLprogram which also comes with the AntennaBook, they're also standard EZNECfileswhich work normally with EZNEC 3.0.Even withoutthe EZNECfiles, the ARRL AntennaBookis a bargain, but the files make it even more so. Also, check http://www.cebik.comfor models andother good information.