diff --git a/dsp.c b/dsp.c
index e36bf5d..484dfac 100644
--- a/dsp.c
+++ b/dsp.c
@@ -22,9 +22,7 @@
 #include "nanovna.h"
 
 int16_t samp_buf[SAMPLE_LEN];
-int16_t ref_state[STATE_LEN];
 int16_t ref_buf[SAMPLE_LEN];
-int16_t refiq_buf[AUDIO_BUFFER_LEN];
 
 const int16_t sincos_tbl[48][2] = {
   { 10533,  31029 }, { 27246,  18205 }, { 32698,  -2143 }, { 24636, -21605 },
@@ -86,6 +84,7 @@ dsp_process(int16_t *capture, size_t length)
 void
 calculate_gamma(float gamma[2])
 {
+  // calculate reflection coeff. by samp divide by ref
   float rs = acc_ref_s;
   float rc = acc_ref_c;
   float rr = rs * rs + rc * rc;
diff --git a/main.c b/main.c
index 11d69df..5aa142e 100644
--- a/main.c
+++ b/main.c
@@ -272,8 +272,6 @@ duplicate_buffer_to_dump(int16_t *p)
     p = samp_buf;
   else if (dump_selection == 2)
     p = ref_buf;
-  else if (dump_selection == 3)
-    p = refiq_buf;
   memcpy(dump_buffer, p, sizeof dump_buffer);
 }
 #endif
diff --git a/nanovna.h b/nanovna.h
index ef70d6a..73f1a78 100644
--- a/nanovna.h
+++ b/nanovna.h
@@ -80,13 +80,9 @@ extern int16_t rx_buffer[];
 #define STATE_LEN 32
 #define SAMPLE_LEN 48
 
-extern int16_t ref_state[];
 extern int16_t ref_buf[];
 extern int16_t samp_buf[];
 
-//extern int16_t refq_buf[];
-extern int16_t refiq_buf[];
-
 void dsp_process(int16_t *src, size_t len);
 void reset_dsp_accumerator(void);
 void calculate_gamma(float *gamma);