NEC-LIST:NEC 4.1 & g77

Hello, all. I used the g77 compiler (p/o GCC-2.95) that comes with
the Red Hat Linux 7.1 distribution CDs to compile NEC 4.1D. The g77
compiler options were those used by Jergen Von Hagen in compiling NEC
2D (re ACES Newsletter Nov '98):

        g77 -O3 -fno-emulate-complex -funroll-loops NEC41D.f

While the compile process issued a couple of warnings about same name
for global and intrinsic and array size, the compile completed
without error.

I find that when I run a simple halfwave horizontal dipole problem
over an infinite but imperfect (Sommerfeld) ground, I obtain antenna
impedances that are significantly (and I believe incorrect) different
than those obtained with my ancient HP 755 workstation running HPUX
(NEC4 compiled with HP f77 compiler). OTOH, I obtain identical
results on the two platforms when the dipole is over an infinite,
perfect ground. Based upon past experience, I trust the results of
the HP platform.

I also tried a straight g77 compile (i.e. g77 NEC4D.f) but with no improvement.

The Red Hat 7.1 platform is a Panasonic Toughbook CF-27 with a 500
MHz Pentium III processor. I'd appreciate hearing from anyone with
g77/NEC4 experience. A burning question is whether the legacy NEC 4.1
source code from LLNL is truly compatible with g77. (Jerry Burke at
LLNL and I have had some previous discussions.) I like the idea of a
free and open source compiler from the GNU organization but cannot
afford to devote hours to rewriting and testing compiled NEC source
code.

Thanks for your time and any insight. Sincerely,

-- 
        __    __     ______       __   John Wood
       /  |\ / /\   / ____ \     / /\  Code 5551
      / | ||/ / /  / /\__/ /|   / / /  U.S. Naval Research Lab
     / /| |/ / /  / /_/_/ / /  / / /   4555 Overlook Avenue, SW
    / / |   / /  / ___   / /  / / /    Washington, DC 20375-5337
   / / /|  / /  / /\_| |\_/  / /_/_    (202) 767-2608
  /_/ / |_/ /  /_/ / |_||   /_____/\   (202) 767-3377 (FAX)
  \_\/  \_\/   \_\/  \_\|   \_____\/   e-mail: wood_at_itd.nrl.navy.mil
                             WWW: http://server5550.itd.nrl.navy.mil
DOST THOU LOVE LIFE?  THEN DO NOT SQUANDER TIME, FOR THAT IS THE 
STUFF LIFE IS MADE OF. - Benjamin Franklin
-- 
The NEC-List mailing list <nec-list_at_gweep.ca>
http://www.gweep.ca/mailman/listinfo.cgi/nec-list