4Wire + Artificial Line - Still being tested.

What is the TransHybrid loss caused by different line lengths?
2x2 matrix model being simulated:-

[V] = [ Line(length) ]  [ nominal exchange input impedance is 300 ohm + 1000 ohm || 220 nF ] [v]
[I]                                                                                          [i]


Use Shunt Termination when you need Io =0 and Vo != 0


Use Series Termination when you need Vo =0 and Io != 0


Hybrid | line | seriesTermination

Calculate Mic to ear gains.
  /*
  This models the hybrid inputing 4 wire to 2 wire [ M ] = [   ] [V]
  see paper on loudness ratings                    [ E ]   [   ] [I]
  */
M, E near Phone
m, e far phone

Complex Z
//Th SIN has
//The terminal Figure 1: Terminal Complex Impedance Network = 370+ 620//310nf

//The nominal exchange input impedance is 300 ohm + 1000 ohm || 220 nF (see Figure 2).

// The Balance impedance for the exchange is not published.

we need to plot what we present. we want E/M where M is 4 wire Vout, E = 4 wire Vin 

--[line]--[OC term]--[short]

V near Voltage,I near Current
v far voltage, i far current

//The terminal Figure 1: Terminal Complex Impedance Network = 370+ 620//310nf
    var z_complex_z = z_abc(370, 620, 310.0e-9 , freq[c] );

//The nominal exchange input impedance is 300 Ù + 1000 Ù || 220 nF (see Figure 2).
    var z_complex_znom = z_abc(300.0, 1000.0, 220.0e-9 , freq[c] );

    w  =freq[c]*2*pi;

    rar=1.0;rai=0.0;
    rbr=0.0;rbi=0.0;
    rcr=0.0;rci=0.0;
    rdr=1.0;rdi=0.0;
    /*
    This models the hybrid inputing 4 wire to 2 wire [ M ] = [   ] [V]
    see paper on loudness ratings                    [ E ]   [   ] [I]

    convert();

    /* We want E/M , use convert() to get
    [E] = [ a b ] [M]
    [I]   [ c d ] [V]

    V is a function of M, so append series Zterm and this allows us to short V
    */
    // The Balance impedance for the exchange is not published
    twoto4(z_complex_z.r,z_complex_z.i,   z_complex_znom.r,z_complex_znom.i );
    /* lines */
    lines( lineLength_ );
    //Add series Termination so that output can be short circuited.
    // add Term Z = 370+ 620//310nf
    // add exchange Z = 300+ 1000//220nf
    // if we want Zin add Zexch
    if ( term ==0 ){
      multz(( z_complex_z.r, z_complex_z.i )
    } else {
      multz( z_complex_znom.r, z_complex_znom.i )
    }
    convert();
    /* We want E/M , used convert() to get
    [E] = [ a b ] [M]
    [I]   [ c d ] [V]

    output is short circuited to allow V=0 so E = a M

    */