Thanks to everyone who responded to my posting about our clubs proposed 40m
elevated radial vertical for field day. My posting was meant to obtain answers
to what appears to be a modeling problem rather than how to get good results
for the 40m fd operation. The club is w7dk, the Tacoma radio club which is the
oldest club in the USA and has some of us members almost as old. There is a
lot of knowhow in the club but not many members have modeling knowhow. The
site we are using this year has few trees but two 100' firs that are space 240'
apart will support a 40m dipole for N/S operation. Hung from this dipole will
be a three wire yagi for E/W operation. The 40m SSB location does not have
nice trees so the vertical is being considered.
The modeling problem:
My model used 31 segments on all wires. The radials slope from 10' at the
feedpoint to 1' at the end (not connected to ground).
My EZNEC being used in EZNEC+ v4.0. I selected Real and High Accuracy for the
ground type. The other choice is MINiNEC.
Pages 64/65/66 in the EZNEC manual describe the ground type to use. These
pages refer to EZNEC, EZNEC-M, EZNEC/4, and EZNEC PRO, but not to my EZNEC+!
Page 65 states not to use MININIC-type if "there are horizontal wires less than
about 0.2 wavelength. This page also states that the High-Accuracy ground
shoud be good down to at least .005 wavelength. Page 66 states that "The High
Accuracy ground type should be used any time the model contains low horizontal
wires, and (is required for modeling buried wires with EZNEC/4)"
It isn't clear to me whether my EZNEC+ v4.0 can use the High Accuracy ground
type or must use MININEC ground type?
I will appreciate all further comments
k7puc
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