By which you probably refer to the NEC2 code base. NEC2 is public domain, so that is what most hackers use. The native UI is column-senstive punch cards. Blessedly, there are people that have put more modern front-ends on the NEC2 back-end.
NEC2 is OK-ish, as long as you avoid the well-known bugs. NEC4 fixes some of the bugs, but falls under ITAR, so requires a license and can't be exported (last I knew, anyway). There are also multi-kilo-dollar-per-seat antenna modeling packages available commercially.
NEC2 is pretty old, and an interesting story I heard about the validation of the model was that the DOD, having helicopters handy, stuffed a helicopter full of instruments and flew it around an antenna range to capture ground-truth data for antennas that had been built from models. Last week I was talking with my friend N6BT, who has been in the antenna business for decades. For 3 or so years he has had a quad-rotor that he flies around with a signal generator, and uses the GPS time from the quad-rotor to correlate GPS time-stamped data from his ground-based spectrum analyzer to collect actuals. He is finding MANY discrepancies (primarily at low angles) between NEC4 and actual, due to the sketchy ground models.
That has been my experience as well, at work we have a multi-kilobuck simulation package but we still put the antenna on our range to test it. The range consists of basically a robot arm that can hold the antenna under test (AUT) in any orientation, a transceiver/spectrum analyzer that can move forward or back to get into the near, Fresnel, and far ranges, and a transceiver/spectrum analyzer that is connected to the AUT.
Comparing simulations to actual always yields some interesting nuggets of information.
By which you probably refer to the NEC2 code base. NEC2 is public domain, so that is what most hackers use. The native UI is column-senstive punch cards. Blessedly, there are people that have put more modern front-ends on the NEC2 back-end.
NEC2 is OK-ish, as long as you avoid the well-known bugs. NEC4 fixes some of the bugs, but falls under ITAR, so requires a license and can't be exported (last I knew, anyway). There are also multi-kilo-dollar-per-seat antenna modeling packages available commercially.
NEC2 is pretty old, and an interesting story I heard about the validation of the model was that the DOD, having helicopters handy, stuffed a helicopter full of instruments and flew it around an antenna range to capture ground-truth data for antennas that had been built from models. Last week I was talking with my friend N6BT, who has been in the antenna business for decades. For 3 or so years he has had a quad-rotor that he flies around with a signal generator, and uses the GPS time from the quad-rotor to correlate GPS time-stamped data from his ground-based spectrum analyzer to collect actuals. He is finding MANY discrepancies (primarily at low angles) between NEC4 and actual, due to the sketchy ground models.