I use lumped circuit analysis when dealing with lumped circuits, and
distributed circuit analysis when dealing with distributed circuits.
EZNEC's loads are lumped elements, so when you're talking about EZNEC
loads, you're talking about lumped elements.

Roy Lewallen, W7EL

Cecil Moore wrote:
Roy Lewallen wrote:

Of course it doesn't account for phase shifts of current, since there
aren't any. It does account for voltage phase shift. It uses the same
equations I learned in freshman circuits class. Perhaps they taught
those same equations in Texas, too, but I can't be sure.


Roy,
We are talking about distributed networks. Of course, there is a phase
shift in the current as well as the voltage. You and W8JI seem to be
using lumped circuit analysis when you should be using distributed
network analysis. The center loading coil for a 75m mobile antenna
is an appreciable percentage of an electrical wavelength so you cannot
use your lumped circuit analysis without introducing errors.

Roy Lewallen wrote:

I use lumped circuit analysis when dealing with lumped circuits, and
distributed circuit analysis when dealing with distributed circuits.
EZNEC's loads are lumped elements, so when you're talking about EZNEC
loads, you're talking about lumped elements.

Roy Lewallen, W7EL

Hi Roy,

Wouldn't it be better not to lump any portions of an antenna that are a
part of its electrical length?

73, Jim AC6XG

Yes. If any real component has signficant length, it's best to model it
as wires if possible. If it's not possible or practical to model it as
wires, about the best you can do is as I've suggested befo model it
as a wire of the length and diameter of the component, and insert one or
more loads to represent the low frequency impedance of the component.
That's about as good as you can do with the limited set of modeling
objects you have.

Roy Lewallen, W7EL

Jim Kelley wrote:

Roy Lewallen wrote:

I use lumped circuit analysis when dealing with lumped circuits, and
distributed circuit analysis when dealing with distributed circuits.
EZNEC's loads are lumped elements, so when you're talking about EZNEC
loads, you're talking about lumped elements.

Roy Lewallen, W7EL


Hi Roy,

Wouldn't it be better not to lump any portions of an antenna that are a
part of its electrical length?

73, Jim AC6XG