diff --git a/firmware/application/tone_key.cpp b/firmware/application/tone_key.cpp
index 138cd407..d9655938 100644
--- a/firmware/application/tone_key.cpp
+++ b/firmware/application/tone_key.cpp
@@ -25,10 +25,11 @@
 
 namespace tonekey {
 
+// Keep list in ascending order by tone frequency
 const tone_key_t tone_keys = {
     {"None", 0.0},
-    {"0 XZ", 67.000},
-    {"1 WZ", 69.400},
+    {"1 XZ", 67.000},
+    {"39 WZ", 69.300},
     {"2 XA", 71.900},
     {"3 WA", 74.400},
     {"4 XB", 77.000},
@@ -77,11 +78,11 @@ const tone_key_t tone_keys = {
     {"37 M6", 241.800},
     {"38 M7", 250.300},
     {"50 0Z", 254.100},
+    {"Shure 19kHz", 19000.0},
     {"Axient 28kHz", 28000.0},
-    {"Senn. 32.768k", 32768.0},
     {"Senn. 32.000k", 32000.0},
     {"Sony 32.382k", 32382.0},
-    {"Shure 19kHz", 19000.0}};
+    {"Senn. 32.768k", 32768.0}};
 
 void tone_keys_populate(OptionsField& field) {
     using option_t = std::pair<std::string, int32_t>;
@@ -120,7 +121,7 @@ std::string tone_key_string_by_value(uint32_t value) {
 tone_index tone_key_index_by_value(uint32_t value) {
     float diff;
     float min_diff{(float)value};
-    float fvalue{(float)((min_diff + 50.0) / 100.0)};
+    float fvalue{(float)(min_diff / 100.0)};
     tone_index min_idx{-1};
     tone_index idx;
 
diff --git a/firmware/baseband/proc_nfm_audio.cpp b/firmware/baseband/proc_nfm_audio.cpp
index 85251932..e3aef78a 100644
--- a/firmware/baseband/proc_nfm_audio.cpp
+++ b/firmware/baseband/proc_nfm_audio.cpp
@@ -72,7 +72,7 @@ void NarrowbandFMAudio::execute(const buffer_c8_t& buffer) {
                 cur_sample = audio_f[c];
                 if (cur_sample * prev_sample < 0.0) {
                     z_acc += z_timer;
-                    z_timer = 0;
+                    z_timer = 1;
                     z_count++;
                 } else
                     z_timer++;