diff --git a/decoder_modules/m17_decoder/src/m17dsp.h b/decoder_modules/m17_decoder/src/m17dsp.h
index d1513cd4..8f1e6a72 100644
--- a/decoder_modules/m17_decoder/src/m17dsp.h
+++ b/decoder_modules/m17_decoder/src/m17dsp.h
@@ -16,7 +16,7 @@ extern "C" {
 #define M17_DEVIATION     2400.0f
 #define M17_BAUDRATE      4800.0f
 #define M17_RRC_ALPHA     0.5f
-#define M17_4FSK_HIGH_CUT 0.5f
+#define M17_4FSK_HIGH_CUT ((1.0f + (1.0f/3.0f)) / 2.0f)
 
 #define M17_SYNC_SIZE            16
 #define M17_LICH_SIZE            96
@@ -123,6 +123,7 @@ namespace dsp {
             float val;
             for (int i = 0; i < count; i++) {
                 val = _in->readBuf[i];
+                printf("%f\n", val);
                 out.writeBuf[i * 2] = (val < 0.0f);
                 out.writeBuf[(i * 2) + 1] = (fabsf(val) > M17_4FSK_HIGH_CUT);
             }
diff --git a/decoder_modules/m17_decoder/src/main.cpp b/decoder_modules/m17_decoder/src/main.cpp
index 5c9d5372..168da48b 100644
--- a/decoder_modules/m17_decoder/src/main.cpp
+++ b/decoder_modules/m17_decoder/src/main.cpp
@@ -32,7 +32,7 @@ ConfigManager config;
 
 class M17DecoderModule : public ModuleManager::Instance {
 public:
-    M17DecoderModule(std::string name) : diag(0.8, 480) {
+    M17DecoderModule(std::string name) : diag(0.6, 480) {
         this->name = name;
         lsf.valid = false;
 
@@ -43,10 +43,10 @@ public:
         }
         showLines = config.conf[name]["showLines"];
         if (showLines) {
-            diag.lines.push_back(-0.75f);
-            diag.lines.push_back(-0.25f);
-            diag.lines.push_back(0.25f);
-            diag.lines.push_back(0.75f);
+            diag.lines.push_back(-1.0);
+            diag.lines.push_back(-1.0/3.0);
+            diag.lines.push_back(1.0/3.0);
+            diag.lines.push_back(1.0);
         }
         config.release(true);