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eddie,
if you look at what cebik says about gammas in his tales and technicals regarding gamma calculators and models plus what he told me about it been difficult getting accurate models of the sigma and what nec says about segment junctions, its pretty clear that nec will have multiple problems with the sigma4 style antennas,

you have to deal with the tapered transmissionline formed by the radials having unequal junctions, differeing diameter to the monopole and been tapered,
you have a round hoop interconnecting the radial ends,
nec can have problems even with conventional gammas, not only is the sigma gamma not parallel to the element its feeding it is also a tube style and not a gamma rod with lumped capacitance,

i think you are getting closer than the models we have seen so far but i don't have a clue how you are doing it within the limitations of eznec

<blockquote data-quote="bob85" data-source="post: 242708" data-attributes="member: 18">eddie, if you look at what cebik says about gammas in his tales and technicals regarding gamma calculators and models plus what he told me about it been difficult getting accurate models of the sigma and what nec says about segment junctions, its pretty clear that nec will have multiple problems with the sigma4 style antennas,you have to deal with the tapered transmissionline formed by the radials having unequal junctions, differeing diameter to the monopole and been tapered, you have a round hoop interconnecting the radial ends,nec can have problems even with conventional gammas, not only is the sigma gamma not parallel to the element its feeding it is also a tube style and not a gamma rod with lumped capacitance,i think you are getting closer than the models we have seen so far but i don&#039;t have a clue how you are doing it within the limitations of eznec<img src="https://cdn.jsdelivr.net/joypixels/assets/8.0/png/unicode/64/1f44d.png" class="smilie smilie--emoji" loading="lazy" width="64" height="64" alt=":thumbup1:" title="Thumbs Up&nbsp; &nbsp; :thumbup1:"&nbsp; data-smilie="27"data-shortname=":thumbup1:" /></blockquote>

[QUOTE="bob85, post: 242708, member: 18"] eddie, if you look at what cebik says about gammas in his tales and technicals regarding gamma calculators and models plus what he told me about it been difficult getting accurate models of the sigma and what nec says about segment junctions, its pretty clear that nec will have multiple problems with the sigma4 style antennas, you have to deal with the tapered transmissionline formed by the radials having unequal junctions, differeing diameter to the monopole and been tapered, you have a round hoop interconnecting the radial ends, nec can have problems even with conventional gammas, not only is the sigma gamma not parallel to the element its feeding it is also a tube style and not a gamma rod with lumped capacitance, i think you are getting closer than the models we have seen so far but i don't have a clue how you are doing it within the limitations of eznec:thumbup1: [/QUOTE]

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