EZNEC 3.0 FAQ
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 was
working, but now it fails with the message 'Runtime error 339:
Component dwsbc36.ocx or one of its dependencies not correctly
registered, a file is missing or invalid'.
Several spyware removal programs
incorrectly identify dwspy36.dll, a file used by dwsbc36.ocx, as
spyware and recommend its deletion. (See "What is
dwspy36.dll in the
program directory", below, for information about these files.) The message
occurs when the file is
deleted. Restoring EZNEC
functionality requires restoring dwspy36.dll. Some spyware removal
programs allow this, or it might be restored with an undelete utility.
If neither is possible, running the EZNEC
installation will recreate the file. The current version of EZNEC no
longer uses these files, but v. 3.0 does. So version 3.0 users should
direct any spyware removal programs to not delete them.
When I try to install
EZNEC I get the message 'C:\WINDOWS\SYSTEM32\AUTOEXEC.NT. The system
file is not suitable for running MS-DOS and Microsoft Windows
applications' or other message involving AUTOEXEC.NT.
This is most often caused by the Windows XP
Pack 2 (SP2) installation deleting (for unknown reasons) the
Autoexec.nt file which is required to run 16 bit programs. The EZNEC
installation program is intentionally an older type in order to keep
download size smaller and updates simpler, and requires 16 bit
(DOS-type) operation during part of the process. (EZNEC
doesn't.) You should be able to solve the problem by locating a copy of
Autoexec.nt in your C:\Windows\Repair directory (the directory might be
C:\Winnt\Repair on systems upgraded from Windows 2000) and copying it
into your Windows system directory C:\Windows\System32 (or
C:\Winnt\System on some upgraded systems). If you need further
this doesn't fix the problem, please let me
under Windows XP? Vista? Windows 7?
to all, but not 64 bit
versions of those operating systems. EZNEC pro
requires some modification to run under Vista or Windows 7. EZNEC pro
should contact me
information. No EZNEC
v. 3.0 program type will not install on 64 bit operating systems. See
under 64 bit operating systems?
If you have a 64 bit
operating system (such as the 64 bit versions of XP, Vista, or Windows 7), you must
upgrade to the current version of EZNEC or request a refund. There is no problem running EZNEC v. 3.0 on
a 64 bit computer, as long as the operating system is 32 bit. Except
for versions specifically identified as 64 bit, Windows XP and Vista
are 32 bit systems.
Can EZNEC 3.0
antenna description files I created with an earlier version?
can even read and translate ELNEC (.EN) files -- just include the
extension (.EN) when specifying the name of the file to open. Older
versions of EZNEC can also read
and use files written by
3.0. EZNEC 3.0
uses the same plot file format as
v. 2.0, and can display plots saved by ELNEC or any version of EZNEC.
If I buy the CD-ROM
version, does the CD-ROM have to be in place when running the program?
All necessary files are
installed on your hard drive. The CD-ROM is needed only for
installation. If desired, the CD-ROM files can be copied to a hard
drive or Zip drive and the program installed or re-installed from there.
Where's the manual?
The manual is an
integral part of the program. With EZNEC
3.0 running, In the EZNEC 3.0
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
places in the program by pressing F1. This sort of manual is often
called an "on-line" manual, but people sometimes mistakenly
that term to mean that the manual is on the Internet. It's not.
Is it possible to get
a printed manual?
A version is now available which
you can load into a
word processor and print yourself. If you purchased EZNEC
on a CD-ROM after about September 1, 2000, you'll find it in the
Printable Manual directory on the CD-ROM. Otherwise, you can download
it. Clicking here
you to the page where you can get more information. No printed manual
What's the EZNEC 3.0
limit for EZNEC 3.0
is the same as for earlier versions, 500 segments maximum. This allows
approximately 25 wavelengths of wire, or 50 beam elements. The
professional versions of EZNEC 3.0
accommodate up to
Will EZNEC 3.0
overwrite my ELNEC or DOS EZNEC program?
No. EZNEC 3.0
will not affect these
programs in any way. You can even install it in the same directory if
What's the difference
between 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, independent
program which doesn't require any other program in order to 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-ROM products?
The installed program
is exactly the same -- the
only difference is in the format of the files used for installation.
download product is a single executable file, for convenient
downloading. It expands and creates temporary files during the
installation process, which are deleted when the installation is
complete. The CD-ROM contains several files. Although it also creates
some temporary files during installation, they aren't as large as the
ones created by the download version. Consequently, the download
requires somewhat more disk space (roughly 15 MB) during installation
than the CD-ROM product. Otherwise, there's no difference. Once
installed, the programs and disk space requirements are the same. You
may need to re-install EZNEC
event of a hard drive failure or
change to your computer system, so you should always keep either the
CD-ROM or 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-ROM (with or without the download) to protect
against loss of the program in the event of a hard drive failure.
Doesn't being a
Windows program make EZNEC 3.0 slower than the older DOS versions?
3.0 does its
calculations about 20% faster than previous
calculating engine is a separate FORTRAN executable file which doesn't
make any Windows calls (except to communicate calculation progress to
the main program), and the FORTRAN compiler used for the EZNEC
3.0 calculating engine has better optimization than
used for previous versions. All other operations, such as graphics, are
as fast or faster than earlier versions. One of the slowest operations
in DOS EZNEC
was calculation of wire connections each time a wire
coordinate was changed. This process has been optimized and moved to a
FORTRAN DLL, and runs something like 20 times
before. If you do experience very slow operation of EZNEC
please see the next item.
My EZNEC 3.0 runs
extremely slowly. Why?
Some versions of McAfee Antivirus sofware,
in the background detection mode, can cause extremely slow operation of
3.0 calculations. This problem can suddenly appear
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 runningEZNEC 3.0. So far, this
has been reported only with McAfee version 4, and it appears that
version 6 might not have this effect on EZNEC.
in the EZNEC program directory?
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
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
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
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
Because of this problem, EZNEC
was modified at version 4.0.5 to use a recompiled version of a similar
DesaWare product, rather than dwsbc36.ocx and dwspy36.dll. V. 4.0.9 and
later use an entirely different and newly compiled control. Version 3.0
continues to use the DesaWare files, so version 3.0 users should direct
spyware removal programs to not delete them.
keystroke logging or any other type of user activity
recording, reporting, or Internet connection. For more information
about the SpyWorks package, see
http://www.desaware.com/SpyWorksL2.htm, and for more information about
subclassing, see http://www.desaware.com/Subclassing.htm.
EZNEC 3.0 written in?
The interface portion of the
program was written in
Microsoft Visual Basic 6.0. It consists of about 50,000 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 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
Where can I get more
The CD included with the 20th and later editions of
the ARRL Antenna Book
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
which work normally with EZNEC 3.0.
files, the ARRL Antenna
is a bargain, but the files make it even more so. Also, check http://www.cebik.com
for models and
other good information.