I agree. When I bought my Optibeam OB16-3 and OB2-40, Tom (DF2BO)
didn't send me the EZNEC files but he did send me the resulting plots
for gain and SWR. The manual also specified the element lengths and
diameters. I took my own measurements for the 40m coils and the
tribander feed system, and generated my own EZNEC files. My EZNEC plots
are indistinguishable from Tom's.
By the way, with the help of K9RX who lived about 30 miles line of sight
from me at the time (we both lived on high ground with a small river
valley between us) we measured the actual azimuth patterns, and of
course I could measure the SWR plots. They were extremely close to the
models as well.
Modeling unknown traps might be a bit trickier, though, I suppose.
73,
Dave AB7E
On 4/22/2020 9:34 AM, Jim Brown wrote:
On 4/22/2020 7:51 AM, Robert Harmon wrote:
Good luck on getting the files. They won't give you theiir Eznec
files.
Who is the "they" in this post? I looked all through this post and
quoted stuff to find "them." If you're referring to mfrs, what makes
you think they use NEC for design? There are multiple modeling programs.
It's easy enough to produce an EZNEC file for an antenna that doesn't
include inductors or capacitors -- all you need a a measuring tape and
a caliper to determine element diameters. In his very useful
self-published "Array of Light," N6BT includes detailed descriptions
of many Force 12 antennas he designed for the company he owned.
73, Jim K9YC
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