My anti-virus software says EZNEC is infected with a virus. Is it?

No. The number of false positive virus reports has been steadily increasing for various files in all versions of EZNEC, including ones which have been in use and unchanged for many years. Web research shows that this is also affecting many other programs. (Search, for example, "false positive virus", without the quotation marks, with Google.) The cause is that anti-virus programs now include "heuristic" detection methods which use proprietary routines that attempt to detect unknown viruses rather than identifying known malevolent code. There also seems to be an effort in this competitive market to have a product "find" more "viruses" than competing products. The result is a large and increasing number of false positive virus warnings.

When false positives began appearing, I was able to contact the offending anti-virus companies to have them correct their routines to remove the false indications. Some were very responsive, some were not. Such a large number of products and files are now involved, however, that it's no longer possible to take this approach. One major program manufacturer didn't bother to respond at all when I contacted them recently, so apparently the complaints are too numerous for them to handle.

Extensive efforts are made to keep the machine used for EZNEC creation clean and files free from any possibility of infection. If you feel uneasy about continuing to use EZNEC following an anti-virus alert, I recommend that you submit the file in question to the anti-virus program company for analysis; some of them, at least, have a mechanism to do this. I would like to know immediately if any EZNEC file is ever confirmed to have a virus infection, and I will give it immediate action. However, this has never happened in spite of the rapidly increasing rate of reports. I would encourage those who see false positive indications to consider whether to believe other reports, both positive and negative, their anti-virus program is producing, and perhaps try some other company's offering.

NOTE: Beginning with EZNEC v. 5.0.59, the program was recompiled in a way that greatly reduces the number of false positive indications. The fact that there is absolutely no difference in the underlying program content illustrates how poorly implemented many anti-virus programs are. Although a few of the worst ones still find imaginary viruses, the problem is greatly reduced -- for the time being, at least. I highly recommend downloading and installing the latest update. Non-pro users, see "Support/Updates (Maintenance Releases)" in the EZNEC manual for instructions. Pro users, go to the URL printed on the EZNEC Pro CD label.

I am sometimes asked for an anti-virus program recommendation. I've used ESet NOD32 for several years and have found it to be easy to use, unobtrusive, trouble-free, and relatively free of false positive alarms. At the other end of the spectrum, McAfee has consistently been one of the worst at generating false positive indications, deleting files without notice, and continuing to run even when supposedly disabled. I purchased a copy some time ago to test EZNEC and was surprised sometime later to find that by agreeing to the normal legalese license agreement, I had unwittingly also agreed to let them automatically charge my credit card each year for a subscription renewal. So that is a brand I particularly do not recommend.

I have no control over the anti-virus programs, so can do nothing to prevent poorly designed ones from falsely identifying EZNEC files as being infected. All I can do for people who might choose to believe the anti-virus programs is to offer a full and immediate refund for the EZNEC purchase price, which I'm absolutely willing to do.

How do I install EZNEC on another machine, or reinstall it?

If you purchased a CD, you simply run its file setup.exe on the new machine. If you didn't, you need the file you downloaded when you purchased EZNEC. This file is eznec50.exe (standard program) or eznec50+.exe (EZNEC+). Copy it to the machine on which you want to install EZNEC, and run it. If you don't have any way to back up this file, you should purchase the CD.

Will EZNEC v. 5.0 run under Windows XP? Vista? 7? 8?

Yes to all. It will run under Windows 98, ME, 2000, XP, Vista, 7, and 8.

Will EZNEC v. 5.0 run under 64 bit operating systems?

Yes.

Will EZNEC v. 5.0 run under Windows 95? NT4.0?

I'm sorry, no. Following current trends, the compiler used for creating the calculating engines won't produce Windows 95-compatible code, and at least one of the third-party components used for advanced functionality won't operate under Windows 95. Windows NT4.0 requires additional support files so isn't practical to support given its very small and decreasing current usage.

Does EZNEC v. 5.0 use NEC-4 for calculations?

Of the five EZNEC v. 5.0 program types (demo, standard EZNEC, EZNEC+, EZNEC Pro/2, and EZNEC Pro/4) only EZNEC Pro/4 uses NEC-4. NEC-2 is the calculating engine used by the other EZNEC programs. See the next item, below, for more information.

What are the differences between the standard, plus and professional programs?

EZNEC+ has all the features of the standard program, plus:

• 1500 segments vs. 500 for the standard program -- allowing very complex antennas to be analyzed.
• Circular polarization far field analysis in addition to the linear polarization capability of the standard program.
• Double-precision calculating engine in addition to the standard mixed-precision engine.
• Easy importation of wire coordinates (GW lines) from NEC-format files.
• Additional SWR sweep displays: Smith chart, return loss, and reflection coefficient magnitude.
• 10,000 frequency sweep steps vs. 1000 for the standard program.
• Writes input files for IONCAP/VOACAP propagation programs.
• Additional wire duplication and manipulation features.
  

There are two professional (EZNEC Pro) programs, EZNEC Pro/2 and EZNEC Pro/4. They are identical except that EZNEC Pro/4 can use NEC-4 for calculations as well as the NEC-2 used by the other EZNEC program types.

In addition to the features of EZNEC+, the professional programs include:

• 20,000 segment capability (vs. 500 for EZNEC and 1,500 for EZNEC+).
• Ground wave analysis (of interest mostly to AM broadcasters).
• Automated rectangular wire grid creation.
• Loss can be included in wire insulation.
• The ability to read and write files in NEC format.
• Plane wave excitation.
• 100,000 frequency sweep steps.

The primary advantages of NEC-4 are that buried conductors can be modeled, and NEC-4 is relatively free of the small error produced by NEC-2 when analyzing connected wires of different diameters.

EZNEC Pro/2 is $500, EZNEC Pro/4 is $650. Purchasers of EZNEC Pro/4 must first obtain an NEC-4 license. At the time of this writing, NEC-4 prices range from $300 for a U.S. non-commercial or educational license to $1500 for a non-U.S. commercial license. However, prices change, so please consult the LLNL NEC-4 web site https://ipo.llnl.gov/?q=technologies-software-browse_software-app&s=NEC for current information. For more information about EZNEC Pro, see the EZNEC Pro web page.

Can EZNEC v. 5.0 use the antenna description files I created with an earlier version?

Absolutely! EZNEC v. 5.0 can even read and translate DOS EZNEC (.EZ) and ELNEC (.EN) files -- just include the extension (.EN) when specifying the name of an ELNEC file to open. Older versions of EZNEC can also read and use files written by EZNEC v. 5.0, although new objects not existing in the older versions will be ignored. EZNEC v. 5.0 uses the same plot file format as EZNEC v. 2.0 through 4.0, and can display plots saved by ELNEC or any version of EZNEC.

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

No. All necessary files are installed on your hard drive. The CD is needed only for installation. If desired, the CD files can be copied to a hard drive or other storage medium and the program installed or re-installed from there.

Where's the manual?

The manual is an integral part of the program. With EZNEC v. 5.0 running, In the EZNEC v. 5.0 Control Center (the main window), click Help on the menu bar, then choose Contents to view the manual. You can also open the manual to the relevant topic from many places in the program by pressing F1.

Is it possible to get a printed manual?

Yes, if you're willing to print it yourself. If you purchased EZNEC on a CD, you'll find it in the Printable Manual directory on the CD-ROM. Otherwise, you can download it. Clicking here will take you to the page where you can get more information. No pre-printed manual is available.

What are the EZNEC and EZNEC+ v. 5.0 segment limits?

The limit for EZNEC v. 5.0 is the same as for earlier versions, 500 segments maximum. This allows approximately 25 wavelengths of wire, or 50 beam elements. EZNEC+ v. 5.0 allows 1,500 segments, and the professional EZNEC v. 5.0 programs accommodate up to 20,000 segments.

Will EZNEC v. 5.0 overwrite previous versions?

EZNEC v. 5.0 will overwrite and update EZNEC v. 3.0 or 4.0 if installed in the same directory. It will not affect earlier (DOS) versions.

Will installing or uninstalling EZNEC erase or overwrite my existing description or trace files?

Absolutely not!

What's the difference between the upgrade version and full program?

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

Is there any difference between the download and CD products?

No. The CD contains the same single executable file you get if you download. The CD also contains the printable manual, but that's available at the web site. You may need to re-install EZNEC in the event of a hard drive failure or change to your computer system, so you should always keep either the CD or a copy of the downloaded file. If you don't have any way to back up the downloaded file on some medium other than your primary hard drive, you should order the CD (with or without the download) to protect against loss of the program in the event of a hard drive failure.

My EZNEC v. 5.0 runs extremely slowly. Why?

Some versions of McAfee Antivirus sofware, when running in the background detection mode, can cause extremely slow operation of EZNEC calculations. This problem can suddenly appear when the antivirus software is updated. Apparently, the antivirus software intercepts and analyzes the communications between the calculating engine and the main program. These communications are numerous and frequent, so the rather slow analysis process by the antivirus program greatly slows EZNEC operation. The only certain solution is to disable the background checking feature of the McAfee software while running EZNEC. So far, this has been reported only with McAfee version 4, and it appears that version 6 and later versions might not have this effect on EZNEC. This isn't certain, however. Other virus-detecting software could possibly have a similar effect, so if you encounter exceptionally slow operation, try disabling any anti-virus software you have running, and let me know if it solves the problem.

What is dwspy36.dll in the EZNEC program directory?

Because of the problems described next, this file and dwsbc36.ocx are no longer used by EZNEC. If they're in the EZNEC directory, they're left over from an earlier version and can safely be deleted. I don't, however, recommend deleting them from the Windows system directory (where some earlier versions of EZNEC installed them) because some other legitimate application might be using them. Some people have expressed concern about dwspy36.dll and wonder what its function is. This file is a "subclassing" control, part of a third-party utility package called SpyWorks, purchased from Desaware, a highly respected company which is well known to the Visual Basic programming community. This package allows functionality beyond that provided by Visual Basic or normal Windows programming but despite its rather sinister name is not "spy" software. When you attempt to reduce the size of graphical windows below a certain point, EZNEC limits the minimum size. This size limiting isn't possible with Visual Basic (except with "bounce-back" type operation), so a technique called "subclassing" is used. EZNEC intercepts the normal Windows message sent when a window is resized and directs it to code that limits the window size. The SpyWorks control (dwsbc36.ocx, which uses dwspy36.dll) allows this functionality. (It's apparently so named because of its ability to "spy on" -- intercept -- messages sent to and from the Windows operating system by applications during normal operation.) Some versions of EZNEC installed dwsbc36.ocx and dwspy36.dll in the EZNEC program directory; other versions installed them in the Windows system directory instead. An increasing number of spyware removal programs misidentify dwspy36.dll as spyware and delete it, which caused EZNEC to crash. Because of this problem, EZNEC was modified early in v. 4.0 to use a different dll, rather than dwsbc36.ocx and dwspy36.dll. No version of EZNEC does keystroke logging or any other type of user activity recording, reporting, or Internet connection. For more information about the SpyWorks package, see http://desaware.com/products/universalcom/spyworks/index.aspx.

What language is EZNEC v. 5.0 written in?

The interface portion of the program was written in Microsoft Visual Basic 6.0. It consists of more than 70,000 lines of source code, not counting comments. I wrote every line, and it took about two years of essentially full time work to develop the first Windows version. The calculating engine is a modified version of the public domain NEC-2 program. It's written in Fortran, and incorporated as a separate executable file.

Where can I get more EZNEC models?

The CD included with the 20th and later editions of the ARRL Antenna Book has several hundred EZNEC models of a wide variety of antennas. While specially created to work with the EZNEC ARRL program which also comes with the Antenna Book, they're also standard EZNEC files which work normally with EZNEC v. 5.0, EZNEC+ v. 5.0, and EZNEC Pro. Even without the EZNEC files, the ARRL Antenna Book is a bargain, but the files make it even more so. Also, check http://www.cebik.com for models and other good information.