NEC-LIST: ARRL log coordinate system?

I sent this several days ago, but for some reason it bounced. It may
still be useful:

>From measurements of the ARRL form, I determined:

R/OR = 0.89^(-dB/2)

where

OR = the distance from the center to the outer ring of the graph
R = the distance from the center to the dB value in question
dB = dB relative to the outer ring value

For example, if the radius of the graph is 10 cm (that is, the outer
ring is 10 cm from the center), with 0 dBi at the outer ring, the -6
dBi ring would be

  R = 0.89^(6/2) X 10 = 7 cm from the center.

Roy Lewallen

On Wed, 17 Dec 1997, pinoz_at_tin.it wrote:
>Please, can somebody explain how it is defined the
>
> ARRL Log coordinate system.
>
>I want to plot the output of NEC2 in this system but I
>can't figure the transformation formula.
>
>Thanks in advance.
>
> Pino
Received on Fri Jan 09 1998 - 10:15:49 EST