#!/usr/bin/python -u

###----------------------------------------------------------------###
##
##     Author : David Billsbrough <kc4zvw@earthlink.net>
##    Created : Monday, January 14, 2008 at 01:10:27 AM (EST)
##    License : GNU General Public License - version 2
##    Version : $Revision: 0.2 $
##   Warranty : None
##
###----------------------------------------------------------------###

# $Id: moxon.py,v 0.2 2008/01/14 07:46:40 kc4zvw Exp kc4zvw $ 

import math, os, sys

""" Calculate_Moxon_Rectangle """

AA = -0.0008571428571
AB = -0.009571428571
AC =  0.3398571429
BA = -0.002142857143
BB = -0.02035714286
BC =  0.008285714286
CA =  0.001809523381
CB =  0.01780952381
CC =  0.05164285714
DA =  0.001
DB =  0.07178571429

wire_units = 0

def displayBanner():
	os.system("clear")		# Clear Screen
	print
	print 'Program to calculate the dimensions of a Moxon Rectangle.'
	print
	print 'All equations correlated to NEC antenna modeling software for wire'
	print 'diameters from 1E-5 to 1E-2 wavelengths.'
	print
	print 'Designed by L. B. Cebik, W4RNL'
	print 'Ported to Python by David Billsbrough, KC4ZVW'
	print

""" Main begins here """

while (1):
	displayBanner()

	sys.stdout.write('Enter desired frequency in MHz : ')
	freq = float(sys.stdin.readline())

	print 'Select units for wire diameter in 1. Inches, 2. Millimeters, 3. Wavelengths'

	while ((wire_units < 1) or (wire_units > 3)):
		sys.stdout.write("Choose 1, 2 or 3 : ")
		wire_units = int(sys.stdin.readline())
		print

	sys.stdout.write("Enter wire diameter in your selected units : ")
	wd = float(sys.stdin.readline())

	if (wire_units == 1):
		wli = 11802.71 / freq
		dw = wd / wli
	elif (wire_units == 2):
		wli = 299792.5 / freq
		dw = wd / wli
	elif (wire_units == 3):
		dw = wd
	else:
		print "Invalid option."
		sys.exit(1)

	print "Wire diameter in wavelengths: %f" % dw

	d1 = 0.4342945 * math.log10(dw)

	if (d1 < -6):
		print 'Wire diameter less than 0.000001 (1E-6) wavelengths:  Results uncertain.'

	if (d1 > -2):
		print 'Wire diameter greater than 0.01 (1E-2) wavelengths:  Results uncertain.'

	a = (AA * (d1 ** 2)) + (AB * d1) + AC
	b = (BA * (d1 ** 2)) + (BB * d1) + BC
	c = (CA * (d1 ** 2)) + (CB * d1) + CC
	d = (DA * d1) + DB
	e = (b + c) + d

	print
	print 'Moxon Dimensions in Wavelengths:'
	print
	print "  A = %f" % a
	print "  B = %f" % b
	print "  C = %f" % c
	print "  D = %f" % d
	print "  E = %f" % e

	wf = 983.5592 / freq
	wfi = wf * 12

	print
	print "Wavelength: = %7.4f feet or %7.4f inches\n" % (wf, wfi)
	print
	print 'Dimensions in feet and inches'
	print
	print "  A = %7.4g feet or %7.4g inches" % (a * wf, a * wfi)
	print "  B = %7.4g feet or %7.4g inches" % (b * wf, b * wfi)
	print "  C = %7.4g feet or %7.4g inches" % (c * wf, c * wfi)
	print "  D = %7.4g feet or %7.4g inches" % (d * wf, d * wfi)
	print "  E = %7.4g feet or %7.4g inches" % (e * wf, e * wfi)
	print

	print 'Another Value = 1, Stop = 2: '
	p = int(sys.stdin.readline())

	if (p != 1): break

print

sys.exit(0)

# End of script