REM calculation of single layer air cored inductor diameter
      ANSWER = 0
      ANSWERS =0
      UP = 0
      upper =0
      REM d = diameter of coil in inches
      d = 12
      REM z = length of coil in inches
      z = 6
      REM inductance of coil in uH
      ind = 250
      UP = ((18*d) + (40*z)) * ind
      ANSWER = SQR(UP/d^2)
      REM PRINT " by diameter = "ANSWER" turns"
      REM raduis calculation
      r = d/2
      l=z
      upper = ((9*r)+(10*l)) * ind
      answers = SQR(upper/r^2)
      PRINT "for inductance of = ";ind"uH"
      PRINT "Coil diameter = ";d" inches";" or ";d*25.4;"mm"
      PRINT "Coil length = ";z" inches";" or ";z*25.4;"mm"
      PRINT "by diameter = "ANSWER" turns"
      PRINT "calculation check by radius = "answers" turns"