FM gain

iq/wavIQ.c

@@ -365,13 +365,13 @@ int main(int argc, char *argv[]) {
 
         case DEMOD:
             z0 = 0;
-            gain = 2.0/PI;
+            gain = 1.0;
             while ( read_csample(fp, &z) != EOF ) {
                 w = z * conj(z0);
                 switch ( phi ) {  // phi'-Algo
-                  case 1: fm = carg(w); break; // = atan2( cimag(w) , creal(w) );
-                  case 2: fm = cimag(w) / (cabs(z0)*cabs(z0)); break;
-                }         //fm3 = cimag(w); // FM: |z|=const
+                  case 1: fm = carg(w)/PI; break; // = atan2( cimag(w) , creal(w) )/PI \in [-1,1];
+                  case 2: fm = cimag(w) / (cabs(z0)*cabs(z0)); break; // for small angles ... gain?
+                }       //fm3 = cimag(w); // FM: |z|=const
                 write_sample(fout, fm*gain);
                 z0 = z;
                 sample++;

rs41/rs41iq.c

@@ -258,15 +258,15 @@ int read_signed_sample(FILE *fp, double *s) {  // int = i32_t
     double x=0, x0=0;
     double complex z, w;
     static double complex z0;
-    double gain = 2.0/M_PI;
+    double gain = 1.0;
 
     if (option_iq) {
         if ( read_csample(fp, &z) == EOF ) return EOF;
         double t = (double)(sample_count) / sample_rate;
         z *= cexp(-t*2*M_PI*df*I);
         w = z * conj(z0);
-        x = gain * carg(w); // d1
-        //x = cimag(w) / (cabs(z0)*cabs(z0)); // d2
+        x = gain * carg(w)/M_PI; // d1
+        //x = _gain * cimag(w) / (cabs(z0)*cabs(z0)); // for small angles ... d2
         z0 = z;
         iqbuf[sample_count % N_IQBUF] = z;
 
@@ -368,7 +368,7 @@ int read_rawbit(FILE *fp, int *bit) {
 
     if (option_iq >= 2) {
 
-        double h = 1.0; // modulation index, GFSK
+        double h = 1.0; // modulation index, GFSK; h(rs41)=0.8?
         double complex z = 0;
         double complex X1 = 0;
         double complex X2 = 0;