David, The NEC-4.2 engine appears to give very good results with buried and close-to-ground wires (the NEC-4.1 engine compares favorably, too). It is instructive to read N6LF's July/August 2016 QEX article on his modeling efforts with buried and close-to-ground wires.
You can get Rudy's article at http://rudys.typepad.com/files/qexjul-aug-2016-bog.pdf. Carl K9LA _________________ Topband Reflector Archives - http://www.contesting.com/_topband
