//**************************************************************************
// JavaScript for folded_dipole.html
//**************************************************************************

//**************************************************************************
// Global Variables and Arrays.
//**************************************************************************

var AWG_Array = new Array(40);

function calcfeed()
{
   //***********************************************************************
   // Get the expected operating frequency.
   //***********************************************************************

   Dipole_Frequency = document.Folded_Dipole.freq_input.value * 1000000

   //***********************************************************************
   // Get the velocity factor.
   //***********************************************************************

   Velocity_Factor = document.Folded_Dipole.veloc_input.value;

   //***********************************************************************
   // Get the effective dipole impedance.
   //***********************************************************************

   dipole_impedance = document.Folded_Dipole.dipole_feed.value;

   //***********************************************************************
   // Set up the AWG array.
   //***********************************************************************

   K = Math.pow((0.46/0.005),(1/39));  // Increment Multiplier
   for ( I = 1; I <= 40; I++ ) {
      N = I+3; AWG_Array[I] = .46/Math.pow(K,N); }

   //***********************************************************************
   // Set the Wire Diameter based on the wire size specifier (AWG, in, mm)
   // and the wire size specified for d1.
   //***********************************************************************

   if (document.Folded_Dipole.d1_size.options[0].selected) {
      d1_Wire_Dia_Dim = document.Folded_Dipole.d1_size.options[0].value;
      d1_Wire_Num = parseInt(document.Folded_Dipole.d1_value.value);
      d1_Wire_Dia = AWG_Array[d1_Wire_Num]; }
   else if (document.Folded_Dipole.d1_size.options[1].selected) {
      d1_Wire_Dia_Dim = document.Folded_Dipole.d1_size.options[1].value;
      d1_Wire_Dia = parseFloat(document.Folded_Dipole.d1_value.value)/1; }
   else {
      d1_Wire_Dia_Dim = document.Folded_Dipole.d1_size.options[2].value;
      d1_Wire_Dia = parseFloat(document.Folded_Dipole.d1_value.value)/25.4; }

   if (d1_Wire_Dia_Dim == "AWG" ) {
      d1_size_out = "#" + d1_Wire_Num + " AWG, " + DIN2FIN(d1_Wire_Dia,64) + ", (" + Rnd(d1_Wire_Dia*25.4,2) + " mm)";
      }
   else {
      d1_size_out = DIN2FIN(d1_Wire_Dia,64) + ", (" + Rnd(d1_Wire_Dia*25.4,2) + " mm)";
      }

   //***********************************************************************
   // Set the Wire Diameter based on the wire size specifier (AWG, in, mm)
   // and the wire size specified for d2.
   //***********************************************************************

   if (document.Folded_Dipole.d2_size.options[0].selected) {
      d2_Wire_Dia_Dim = document.Folded_Dipole.d2_size.options[0].value;
      d2_Wire_Num = parseInt(document.Folded_Dipole.d2_value.value);
      d2_Wire_Dia = AWG_Array[d2_Wire_Num]; }
   else if (document.Folded_Dipole.d2_size.options[1].selected) {
      d2_Wire_Dia_Dim = document.Folded_Dipole.d2_size.options[1].value;
      d2_Wire_Dia = parseFloat(document.Folded_Dipole.d2_value.value)/1; }
   else {
      d2_Wire_Dia_Dim = document.Folded_Dipole.d2_size.options[2].value;
      d2_Wire_Dia = parseFloat(document.Folded_Dipole.d2_value.value)/25.4; }

   if (d2_Wire_Dia_Dim == "AWG" ) {
      d2_size_out = "#" + d2_Wire_Num + " AWG, " + DIN2FIN(d2_Wire_Dia,64) + ", (" + Rnd(d2_Wire_Dia*25.4,2) + " mm)";
      }
   else {
      d2_size_out = DIN2FIN(d2_Wire_Dia,64) + ", (" + Rnd(d2_Wire_Dia*25.4,2) + " mm)";
      }

   //***********************************************************************
   // Get the distance s.
   //***********************************************************************

   if (document.Folded_Dipole.s_size.options[0].selected) {
      s_Width_Dim = document.Folded_Dipole.s_size.options[1].value;
      s_Width = parseFloat(document.Folded_Dipole.s_value.value)/1; }
   else {
      s_Width_Dim = document.Folded_Dipole.s_size.options[1].value;
      s_Width = parseFloat(document.Folded_Dipole.s_value.value)/25.4; }

   s_Width_out = DIN2FIN(s_Width,64) + ", (" + Rnd(s_Width*25.4,2) + " mm)";

   dipole_impedance = document.Folded_Dipole.dipole_feed.value;

   Impedance_Ratio = Math.pow(1+(Math.log(2*s_Width/d1_Wire_Dia)/Math.log(2*s_Width/d2_Wire_Dia)),2);
   Feed_Impedance = dipole_impedance * Impedance_Ratio;

   FD_Length = ((300000000/Dipole_Frequency)/2)*Velocity_Factor;
//   FD_Length_Out = DIN2FIN(FD_Length/.254,32) + ", (" + Rnd(FD_Length,3) + " M)";
//   FD_Length_Out = DFTtoFTIN(FD_Length/.254,1,32) + ", (" + Rnd(FD_Length,3) + " M)";
   FD_Length_Out = DFTtoFTIN(FD_Length*(39.37/12),1,32) + ", (" + Rnd(FD_Length,3) + " M)";

   FD_Data_Out = "Expected Operating Frequency.. = " + F_Scale(Dipole_Frequency,3) + "\n";
//   document.getElementById("Op_Freq").innerHTML = F_Scale(Dipole_Frequency,3);

   FD_Data_Out += "Antenna Velocity Factor....... = " + Rnd(Velocity_Factor,3) + "\n";
//   document.getElementById("Vel_Factor").innerHTML = Rnd(Velocity_Factor,3);

   FD_Data_Out += "Simple Dipole Feed Impedance.. = " + R_Scale(dipole_impedance,3) + "\n";
//   document.getElementById("Dipole_Feed").innerHTML = R_Scale(dipole_impedance,3);

//   FD_Data_Out += "Diameter of d1................ = " + d1_size_out + "\n";
   document.getElementById("D1_Dia").innerHTML = d1_size_out;

//   FD_Data_Out += "Diameter of d2................ = " + d2_size_out + "\n";
   document.getElementById("D2_Dia").innerHTML = d2_size_out;

//   FD_Data_Out += "Width of s.................... = " + s_Width_out + "\n";
   document.getElementById("S_Distance").innerHTML = s_Width_out;

//   FD_Data_Out += "Folded Dipole Feed Impedance.. = " + R_Scale(Feed_Impedance,3) + "\n";
   document.getElementById("Folded_Dipole_Feed").innerHTML = R_Scale(Feed_Impedance,3);

//   FD_Data_Out += "Folded Dipole Length (L)...... = " + FD_Length_Out + "\n";
   document.getElementById("Dipole_Length").innerHTML = FD_Length_Out;

//   document.Folded_Dipole.FD_Data_Out.value = FD_Data_Out;
}