Re: NEC-LIST:GA card

GA is the "arc card", but simply cranks out straight line segments as an
approximation to an arc.
For very small, fat radius, arcs, is will not be accurate. But for
reasonable electrical lenghts, and reasonable radii, the results are fine.

Dick Adler

No difference btwn

"D. B. Miron" <gomiron_at_paulbunyan.net> writes:
> Jim, isn't there a GA command for doing arcs?---Doug Miron
>
> "Jim Lux" <james.p.lux_at_jpl.nasa.gov> writes:
>
> Quoting Pete Smith <n4zr_at_contesting.com>, on Sat 12 Jul 2008 03:08:58 PM
> PDT:
>
> > I occasionally need to plot at least a quarter-circle when modeling
> > real-world antennas - an example is my K3LR lazy-vee array for 80m,
> > where the bottom half of each dipole describes something approaching a
> > quarter-circle on its way from the feedpoint to the bottom end (back at
> > the tower). It would clearly be a better model to describe that lower
> > element as a quarter-circle than as a straight line, for NEC's purposes.
> >
> > Does anyone have a table that describes a 2-dimensional circle in terms
> > of X and Y coordinates? I'd prefer not to reinvent this particular
> > wheel if it already exists somewhere.
>
> there's a couple ways to do this without the coordinates.
> Use GR card (which I've never used...)
>
> Use GM card to make multiple copies of a sort segment rotated around
> the axis of interest, then another GM to move it.
>
> A zero height helix can also do it (although one of the online manuals
> warns of a divide by zero)
>
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