Re: NEC-LIST: ARRL log coordinate system?

    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

I don't know if this is right, but it's what i'm using to emulate it
until i find the 'official' formula:

    #include <math.h> /* For M_LOG10E and exp() */

    int dBtoR (float dB, int r) {
      if (dB <= 0) {
        double k = exp(M_LOG10E/.98*dB/10);
        return(r*k);
      } else {
        fprintf(stderr,"Bad argument: dBtoR(%f,%d)\n",dB,r);
        return(0);
      }
    }

where 'r' is the radius of the circle in display units.

It looks pretty, but i don't know if it's mathmatically in agreement
with the ARRL plots.
                        -- KD6PAG (Networking Old-Timer, RF newbie)
Received on Tue Jan 06 1998 - 09:36:36 EST