nice posty henry,
my ideas about the sigma style antenas come from 30 years of user experience,
i don't understand eznec but cebik did understand it and warned me that getting accurate results from eznec with the sigma style antennas would be very difficult, he never said impossible to model, only that getting accurate results would be very difficult,
from what little i have read there could be issues with that particular design for the reasons i mentioned earlier,
whenever a model does not show what has been repeatable here for 30 years without one instance of any 5/8wave been the equal of the sigma design it makes me suspect the model,
if the performance advantage of the sigma is not repeatable at other locations/ground types ect i would have to suspect that ground type could be responsible,
that does not answer why the sigma style holds its advantage to at least 73ft to feedpoint in an open field over avg/good ground,
i have no proven answer to why we see changes in signal strength as we change monopole and radial length other than we create changes in the relative phase of currents in the radials vs monopole currents,
i explained what i was doing and the observable effects to cebik and he said it was perfectly possible due to the none apparent co-linear effect,
regardless of eznec indicating about the same gain as a 5/8wave or not there is more than the 1db advantage over a 5/8wave groundplane that avanti claim when we compare a 5/8wave to a vector 4000 tuned for maximum signal in this area,
something is causing this effect
