diff --git a/dsp.c b/dsp.c
index 0e1239b..80fa97a 100644
--- a/dsp.c
+++ b/dsp.c
@@ -84,6 +84,7 @@ dsp_process(int16_t *capture, size_t length)
 void
 calculate_gamma(float gamma[2])
 {
+#if 1
   // calculate reflection coeff. by samp divide by ref
   float rs = acc_ref_s;
   float rc = acc_ref_c;
@@ -93,6 +94,13 @@ calculate_gamma(float gamma[2])
   float sc = acc_samp_c;
   gamma[0] =  (sc * rc + ss * rs) / rr;
   gamma[1] =  (ss * rc - sc * rs) / rr;
+#elif 0
+  gamma[0] =  acc_samp_s;
+  gamma[1] =  acc_samp_c;
+#else
+  gamma[0] =  acc_ref_s;
+  gamma[1] =  acc_ref_c;
+#endif
 }
 
 void
diff --git a/main.c b/main.c
index 35a25c6..96648e7 100644
--- a/main.c
+++ b/main.c
@@ -136,8 +136,12 @@ int set_frequency(int freq)
       tlv320aic3204_set_gain(95, 95);
       delay += 10;
     } else
+    if (freq > 600000000 && frequency <= 600000000) {
+      tlv320aic3204_set_gain(60, 60);
+      delay += 10;
+    } else
     if (freq > FREQ_HARMONICS && frequency <= FREQ_HARMONICS) {
-      tlv320aic3204_set_gain(30, 30);
+      tlv320aic3204_set_gain(40, 40);
       delay += 10;
     } else
     if (freq <= FREQ_HARMONICS && frequency > FREQ_HARMONICS) {