diff --git a/firmware/application/apps/analog_audio_app.cpp b/firmware/application/apps/analog_audio_app.cpp
index 85d7bd9d..381871c2 100644
--- a/firmware/application/apps/analog_audio_app.cpp
+++ b/firmware/application/apps/analog_audio_app.cpp
@@ -404,11 +404,7 @@ void AnalogAudioView::update_modulation(ReceiverModel::Mode modulation) {
 }
 
 void AnalogAudioView::handle_coded_squelch(uint32_t value) {
-    tone_index idx = tone_key_index_by_value(value);
-    if (idx >= 0)
-        text_ctcss.set("CTCSS " + tone_key_string(idx));
-    else
-        text_ctcss.set("???");
+    text_ctcss.set(tone_key_string_by_value(value, text_ctcss.parent_rect().width() / 8));
 }
 
 } /* namespace ui */
diff --git a/firmware/application/apps/analog_audio_app.hpp b/firmware/application/apps/analog_audio_app.hpp
index d95a9873..b3a75f2b 100644
--- a/firmware/application/apps/analog_audio_app.hpp
+++ b/firmware/application/apps/analog_audio_app.hpp
@@ -71,10 +71,10 @@ class NBFMOptionsView : public View {
         }};
 
     Text text_squelch{
-        {9 * 8, 0 * 16, 8 * 8, 1 * 16},
+        {7 * 8, 0 * 16, 8 * 8, 1 * 16},
         "SQ   /99"};
     NumberField field_squelch{
-        {12 * 8, 0 * 16},
+        {10 * 8, 0 * 16},
         2,
         {0, 99},
         1,
@@ -200,7 +200,7 @@ class AnalogAudioView : public View {
         {28 * 8, 0 * 16}};
 
     Text text_ctcss{
-        {19 * 8, 1 * 16, 11 * 8, 1 * 16},
+        {16 * 8, 1 * 16, 14 * 8, 1 * 16},
         ""};
 
     std::unique_ptr<Widget> options_widget{};
diff --git a/firmware/application/apps/ui_level.cpp b/firmware/application/apps/ui_level.cpp
index d0dd3c76..742063e0 100644
--- a/firmware/application/apps/ui_level.cpp
+++ b/firmware/application/apps/ui_level.cpp
@@ -216,23 +216,10 @@ size_t LevelView::change_mode(freqman_index_t new_mod) {
 }
 
 void LevelView::handle_coded_squelch(const uint32_t value) {
-    static tone_index last_squelch_index = -1;
-
-    if (field_mode.selected_index() == NFM_MODULATION) {
-        tone_index idx = tone_key_index_by_value(value);
-
-        if ((last_squelch_index < 0) || (last_squelch_index != idx)) {
-            last_squelch_index = idx;
-            if (idx >= 0) {
-                text_ctcss.set("T: " + tone_key_string(idx));
-                return;
-            }
-        } else {
-            return;
-        }
-    }
-
-    text_ctcss.set("             ");
+    if (field_mode.selected_index() == NFM_MODULATION)
+        text_ctcss.set(tone_key_string_by_value(value, text_ctcss.parent_rect().width() / 8));
+    else
+        text_ctcss.set("        ");
 }
 
 } /* namespace ui */
diff --git a/firmware/application/apps/ui_level.hpp b/firmware/application/apps/ui_level.hpp
index a849afd8..862e79d8 100644
--- a/firmware/application/apps/ui_level.hpp
+++ b/firmware/application/apps/ui_level.hpp
@@ -114,7 +114,7 @@ class LevelView : public View {
         }};
 
     Text text_ctcss{
-        {22 * 8, 3 * 16 + 4, 14 * 8, 1 * 8},
+        {22 * 8, 3 * 16 + 4, 8 * 8, 1 * 8},
         ""};
 
     // RSSI: XX/XX/XXX,dt: XX
diff --git a/firmware/application/apps/ui_mictx.hpp b/firmware/application/apps/ui_mictx.hpp
index 0cbb6f28..4c7e724a 100644
--- a/firmware/application/apps/ui_mictx.hpp
+++ b/firmware/application/apps/ui_mictx.hpp
@@ -269,7 +269,7 @@ class MicTXView : public View {
 
     OptionsField options_tone_key{
         {12 * 8, (13 * 8) - 5},
-        23,
+        18,
         {}};
 
     Checkbox check_rogerbeep{
diff --git a/firmware/application/apps/ui_recon.cpp b/firmware/application/apps/ui_recon.cpp
index 4fce5246..88afc6e3 100644
--- a/firmware/application/apps/ui_recon.cpp
+++ b/firmware/application/apps/ui_recon.cpp
@@ -1426,20 +1426,10 @@ size_t ReconView::change_mode(freqman_index_t new_mod) {
 }
 
 void ReconView::handle_coded_squelch(const uint32_t value) {
-    if (field_mode.selected_index() == NFM_MODULATION) {
-        tone_index idx = tone_key_index_by_value(value);
-
-        if ((last_squelch_index < 0) || (last_squelch_index != idx)) {
-            last_squelch_index = idx;
-            if (idx >= 0) {
-                text_ctcss.set("T: " + tone_key_string(idx));
-                return;
-            }
-        } else {
-            return;
-        }
-    }
-    text_ctcss.set("        ");
+    if (field_mode.selected_index() == NFM_MODULATION)
+        text_ctcss.set(tone_key_string_by_value(value, text_ctcss.parent_rect().width() / 8));
+    else
+        text_ctcss.set("        ");
 }
 
 } /* namespace ui */
diff --git a/firmware/application/apps/ui_recon.hpp b/firmware/application/apps/ui_recon.hpp
index b1d25f3e..36f0e0b4 100644
--- a/firmware/application/apps/ui_recon.hpp
+++ b/firmware/application/apps/ui_recon.hpp
@@ -139,7 +139,6 @@ class ReconView : public View {
     int8_t last_rssi_med{-127};
     int8_t last_rssi_max{-127};
     int32_t last_index{-1};
-    tone_index last_squelch_index{-1};
     int64_t last_freq{0};
     std::string freq_file_path{};
     systime_t chrono_start{};
diff --git a/firmware/application/freqman.cpp b/firmware/application/freqman.cpp
index 648e8803..ee6d455b 100644
--- a/firmware/application/freqman.cpp
+++ b/firmware/application/freqman.cpp
@@ -122,6 +122,8 @@ bool load_freqman_file(std::string& file_stem, freqman_db& db, bool load_freqs,
     freqman_index_t bandwidth = -1;
     freqman_index_t step = -1;
     freqman_index_t tone = -1;
+    uint32_t tone_freq;
+    char c;
 
     auto result = freqman_file.open("FREQMAN/" + file_stem + ".TXT");
     if (result.is_valid())
@@ -210,12 +212,26 @@ bool load_freqman_file(std::string& file_stem, freqman_db& db, bool load_freqs,
                 step = freqman_entry_get_step_from_str_short(pos);
             }
             // ctcss tone if any
-            /* disabled until better form
-               pos = strstr(line_start, "c=");
-               if (pos) {
-               pos += 2;
-               tone = tone_key_index_by_value( strtoll( pos , nullptr , 10 ) );
-               } */
+            pos = strstr(line_start, "c=");
+            if (pos) {
+                pos += 2;
+                // find decimal point and replace with 0 if there is one, for strtoll
+                length = strcspn(pos, ".,\x0A");
+                if (pos + length <= line_end) {
+                    c = *(pos + length);
+                    *(pos + length) = 0;
+                    // ASCII Hz to integer Hz x 100
+                    tone_freq = strtoll(pos, nullptr, 10) * 100;
+                    // stuff saved character back into string in case it was not a decimal point
+                    *(pos + length) = c;
+                    // now get first digit after decimal point (10ths of Hz)
+                    pos += length + 1;
+                    if (c == '.' && *pos >= '0' && *pos <= '9')
+                        tone_freq += (*pos - '0') * 10;
+                    // convert tone_freq (100x the freq in Hz) to a tone_key index
+                    tone = tone_key_index_by_value(tone_freq);
+                }
+            }
             // Read description until , or LF
             pos = strstr(line_start, "d=");
             if (pos) {
@@ -284,7 +300,7 @@ bool get_freq_string(freqman_entry& entry, std::string& item_string) {
         item_string = "r=" + to_string_dec_uint(frequency_a / 1000) + to_string_dec_uint(frequency_a % 1000UL, 3, '0');
         item_string += ",t=" + to_string_dec_uint(frequency_b / 1000) + to_string_dec_uint(frequency_b % 1000UL, 3, '0');
         if (entry.tone >= 0) {
-            item_string += ",c=" + tone_key_string(entry.tone);
+            item_string += ",c=" + tone_key_value_string(entry.tone);
         }
     }
     if (entry.modulation >= 0 && (unsigned)entry.modulation < freqman_entry_modulations.size()) {
diff --git a/firmware/application/tone_key.cpp b/firmware/application/tone_key.cpp
index d9655938..d2402426 100644
--- a/firmware/application/tone_key.cpp
+++ b/firmware/application/tone_key.cpp
@@ -27,62 +27,66 @@ namespace tonekey {
 
 // Keep list in ascending order by tone frequency
 const tone_key_t tone_keys = {
-    {"None", 0.0},
-    {"1 XZ", 67.000},
-    {"39 WZ", 69.300},
-    {"2 XA", 71.900},
-    {"3 WA", 74.400},
-    {"4 XB", 77.000},
-    {"5 WB", 79.700},
-    {"6 YZ", 82.500},
-    {"7 YA", 85.400},
-    {"8 YB", 88.500},
-    {"9 ZZ", 91.500},
-    {"10 ZA", 94.800},
-    {"11 ZB", 97.400},
-    {"12 1Z", 100.000},
-    {"13 1A", 103.500},
-    {"14 1B", 107.200},
-    {"15 2Z", 110.900},
-    {"16 2A", 114.800},
-    {"17 2B", 118.800},
-    {"18 3Z", 123.000},
-    {"19 3A", 127.300},
-    {"20 3B", 131.800},
-    {"21 4Z", 136.500},
-    {"22 4A", 141.300},
-    {"23 4B", 146.200},
-    {"24 5Z", 151.400},
-    {"25 5A", 156.700},
-    {"40 --", 159.800},
-    {"26 5B", 162.200},
-    {"41 --", 165.500},
-    {"27 6Z", 167.900},
-    {"42 --", 171.300},
-    {"28 6A", 173.800},
-    {"43 --", 177.300},
-    {"29 6B", 179.900},
-    {"44 --", 183.500},
-    {"30 7Z", 186.200},
-    {"45 --", 189.900},
-    {"31 7A", 192.800},
-    {"46 --", 196.600},
-    {"47 --", 199.500},
-    {"32 M1", 203.500},
-    {"48 8Z", 206.500},
-    {"33 M2", 210.700},
-    {"34 M3", 218.100},
-    {"35 M4", 225.700},
-    {"49 9Z", 229.100},
-    {"36 M5", 233.600},
-    {"37 M6", 241.800},
-    {"38 M7", 250.300},
-    {"50 0Z", 254.100},
-    {"Shure 19kHz", 19000.0},
-    {"Axient 28kHz", 28000.0},
-    {"Senn. 32.000k", 32000.0},
-    {"Sony 32.382k", 32382.0},
-    {"Senn. 32.768k", 32768.0}};
+    {"None", F2Ix100(0.0)},
+    {"1 XZ", F2Ix100(67.0)},
+    {"39 WZ", F2Ix100(69.3)},
+    {"2 XA", F2Ix100(71.9)},
+    {"3 WA", F2Ix100(74.4)},
+    {"4 XB", F2Ix100(77.0)},
+    {"5 WB", F2Ix100(79.7)},
+    {"6 YZ", F2Ix100(82.5)},
+    {"7 YA", F2Ix100(85.4)},
+    {"8 YB", F2Ix100(88.5)},
+    {"9 ZZ", F2Ix100(91.5)},
+    {"10 ZA", F2Ix100(94.8)},
+    {"11 ZB", F2Ix100(97.4)},
+    {"12 1Z", F2Ix100(100.0)},
+    {"13 1A", F2Ix100(103.5)},
+    {"14 1B", F2Ix100(107.2)},
+    {"15 2Z", F2Ix100(110.9)},
+    {"16 2A", F2Ix100(114.8)},
+    {"17 2B", F2Ix100(118.8)},
+    {"18 3Z", F2Ix100(123.0)},
+    {"19 3A", F2Ix100(127.3)},
+    {"20 3B", F2Ix100(131.8)},
+    {"21 4Z", F2Ix100(136.5)},
+    {"22 4A", F2Ix100(141.3)},
+    {"23 4B", F2Ix100(146.2)},
+    {"24 5Z", F2Ix100(151.4)},
+    {"25 5A", F2Ix100(156.7)},
+    {"40 --", F2Ix100(159.8)},
+    {"26 5B", F2Ix100(162.2)},
+    {"41 --", F2Ix100(165.5)},
+    {"27 6Z", F2Ix100(167.9)},
+    {"42 --", F2Ix100(171.3)},
+    {"28 6A", F2Ix100(173.8)},
+    {"43 --", F2Ix100(177.3)},
+    {"29 6B", F2Ix100(179.9)},
+    {"44 --", F2Ix100(183.5)},
+    {"30 7Z", F2Ix100(186.2)},
+    {"45 --", F2Ix100(189.9)},
+    {"31 7A", F2Ix100(192.8)},
+    {"46 --", F2Ix100(196.6)},
+    {"47 --", F2Ix100(199.5)},
+    {"32 M1", F2Ix100(203.5)},
+    {"48 8Z", F2Ix100(206.5)},
+    {"33 M2", F2Ix100(210.7)},
+    {"34 M3", F2Ix100(218.1)},
+    {"35 M4", F2Ix100(225.7)},
+    {"49 9Z", F2Ix100(229.1)},
+    {"36 M5", F2Ix100(233.6)},
+    {"37 M6", F2Ix100(241.8)},
+    {"38 M7", F2Ix100(250.3)},
+    {"50 0Z", F2Ix100(254.1)},
+    {"Shure 19kHz", F2Ix100(19000.0)},
+    {"Axient 28kHz", F2Ix100(28000.0)},
+    {"Senn. 32.000k", F2Ix100(32000.0)},
+    {"Sony 32.382k", F2Ix100(32382.0)},
+    {"Senn. 32.768k", F2Ix100(32768.0)}};
+
+std::string fx100_string(uint32_t f) {
+    return to_string_dec_uint(f / 100) + "." + to_string_dec_uint((f / 10) % 10);
+}
 
 void tone_keys_populate(OptionsField& field) {
     using option_t = std::pair<std::string, int32_t>;
@@ -91,12 +95,11 @@ void tone_keys_populate(OptionsField& field) {
     std::string tone_name;
 
     for (size_t c = 0; c < tone_keys.size(); c++) {
-        if (c && c < 51) {
-            auto f = tone_keys[c].second;
-            tone_name = "CTCSS " + tone_keys[c].first + " " + to_string_dec_uint(f) + "." + to_string_dec_uint((uint32_t)(f * 10) % 10);
-        } else {
+        auto f = tone_keys[c].second;
+        if ((c != 0) && (f < 1000 * 100))
+            tone_name = "CTCSS " + fx100_string(f) + " #" + tone_keys[c].first;
+        else
             tone_name = tone_keys[c].first;
-        }
 
         tone_key_options.emplace_back(tone_name, c);
     }
@@ -104,8 +107,8 @@ void tone_keys_populate(OptionsField& field) {
     field.set_options(tone_key_options);
 }
 
-float tone_key_frequency(const tone_index index) {
-    return tone_keys[index].second;
+float tone_key_frequency(tone_index index) {
+    return float(tone_keys[index].second) / 100.0;
 }
 
 std::string tone_key_string(tone_index index) {
@@ -114,20 +117,65 @@ std::string tone_key_string(tone_index index) {
     return tone_keys[index].first;
 }
 
-std::string tone_key_string_by_value(uint32_t value) {
-    return tone_key_string(tone_key_index_by_value(value));
+// Return string showing frequency only from specific table index
+std::string tone_key_value_string(tone_index index) {
+    if (index < 0 || (unsigned)index >= tone_keys.size())
+        return std::string("");
+    return fx100_string(tone_keys[index].second);
 }
 
+// Return variable-length string showing CTCSS tone from tone frequency
+// Value is in 0.01 Hz units
+std::string tone_key_string_by_value(uint32_t value, size_t max_length) {
+    static uint8_t tone_display_toggle{0};
+    static uint32_t last_value;
+    tone_index idx;
+    std::string freq_str;
+
+    // If >10Hz difference between consecutive samples, it's probably noise, so ignore
+    if (abs(value - last_value) > 10 * 100) {
+        last_value = value;
+        tone_display_toggle = 0;
+        return "        ";
+    }
+    last_value = value;
+
+    // Only display 1/10 Hz accuracy if <1000 Hz; max 5 characters
+    if (value < 1000 * 100)
+        freq_str = "T:" + fx100_string(value);
+    else
+        freq_str = "T:" + to_string_dec_uint(value / 100);
+
+    // Check field length is enough for character counts in the string below
+    if (max_length >= 7 + 2 + 5) {
+        idx = tone_key_index_by_value(value);
+        if (idx != -1)
+            return freq_str + " #" + tone_key_string(idx);
+    } else {
+        // Not enough space; toggle between display of tone received and tone code #
+        if (tone_display_toggle++ >= TONE_DISPLAY_TOGGLE_COUNTER) {
+            if (tone_display_toggle >= TONE_DISPLAY_TOGGLE_COUNTER * 2) tone_display_toggle = 0;
+
+            // Look for a match in the table (otherwise just display frequency)
+            idx = tone_key_index_by_value(value);
+            if (idx != -1)
+                return "T:" + tone_key_string(idx);
+        }
+    }
+    return freq_str;
+}
+
+// Search tone_key table for tone frequency value
+// Value is in 0.01 Hz units
 tone_index tone_key_index_by_value(uint32_t value) {
-    float diff;
-    float min_diff{(float)value};
-    float fvalue{(float)(min_diff / 100.0)};
+    uint32_t diff;
+    uint32_t min_diff{value * 2};
     tone_index min_idx{-1};
     tone_index idx;
 
     // Find nearest match
     for (idx = 0; idx < (tone_index)tone_keys.size(); idx++) {
-        diff = abs(fvalue - tone_keys[idx].second);
+        diff = abs(value - tone_keys[idx].second);
         if (diff < min_diff) {
             min_idx = idx;
             min_diff = diff;
@@ -138,7 +186,7 @@ tone_index tone_key_index_by_value(uint32_t value) {
     }
 
     // Arbitrary confidence threshold
-    if (min_diff < 40.0)
+    if (min_diff < TONE_FREQ_TOLERANCE_CENTIHZ)
         return min_idx;
     else
         return -1;
diff --git a/firmware/application/tone_key.hpp b/firmware/application/tone_key.hpp
index fa26046d..6fc24927 100644
--- a/firmware/application/tone_key.hpp
+++ b/firmware/application/tone_key.hpp
@@ -30,17 +30,22 @@ using namespace ui;
 
 namespace tonekey {
 
+#define TONE_FREQ_TOLERANCE_CENTIHZ (4 * 100)
+#define TONE_DISPLAY_TOGGLE_COUNTER 3
+#define F2Ix100(x) (int32_t)(x * 100.0)
+
 typedef int32_t tone_index;
 
-using tone_key_t = std::vector<std::pair<std::string, float>>;
+using tone_key_t = std::vector<std::pair<std::string, uint32_t>>;
 
 extern const tone_key_t tone_keys;
 
 void tone_keys_populate(OptionsField& field);
-float tone_key_frequency(const tone_index index);
+float tone_key_frequency(tone_index index);
 
-std::string tone_key_string(const tone_index index);
-std::string tone_key_string_by_value(uint32_t value);
+std::string tone_key_string(tone_index index);
+std::string tone_key_value_string(tone_index index);
+std::string tone_key_string_by_value(uint32_t value, size_t max_length);
 tone_index tone_key_index_by_value(uint32_t value);
 
 }  // namespace tonekey
diff --git a/firmware/baseband/proc_nfm_audio.cpp b/firmware/baseband/proc_nfm_audio.cpp
index e3aef78a..e09db1c2 100644
--- a/firmware/baseband/proc_nfm_audio.cpp
+++ b/firmware/baseband/proc_nfm_audio.cpp
@@ -53,7 +53,9 @@ void NarrowbandFMAudio::execute(const buffer_c8_t& buffer) {
         if (ctcss_detect_enabled) {
             /* 24kHz int16_t[16]
              * -> FIR filter, <300Hz pass, >300Hz stop, gain of 1
-             * -> 12kHz int16_t[8] */
+             * -> 12kHz int16_t[8]
+             *
+             * Note we're only processing a small section of the wave each time this fn is called */
             auto audio_ctcss = ctcss_filter.execute(audio, work_audio_buffer);
 
             // s16 to f32 for hpf
@@ -79,9 +81,11 @@ void NarrowbandFMAudio::execute(const buffer_c8_t& buffer) {
                 prev_sample = cur_sample;
             }
 
-            if (z_count >= 30) {
+            z_filter_count++;
+            if ((z_filter_count >= Z_MIN_FILTER_COUNT) && (z_count >= Z_MIN_ZERO_CROSSINGS)) {
                 ctcss_message.value = (100 * 12000 / 2 * z_count) / z_acc;
                 shared_memory.application_queue.push(ctcss_message);
+                z_filter_count = 0;
                 z_count = 0;
                 z_acc = 0;
             }
diff --git a/firmware/baseband/proc_nfm_audio.hpp b/firmware/baseband/proc_nfm_audio.hpp
index e93d7aaf..708dfa2b 100644
--- a/firmware/baseband/proc_nfm_audio.hpp
+++ b/firmware/baseband/proc_nfm_audio.hpp
@@ -36,6 +36,9 @@
 
 #include <cstdint>
 
+#define Z_MIN_FILTER_COUNT 224
+#define Z_MIN_ZERO_CROSSINGS 20
+
 class NarrowbandFMAudio : public BasebandProcessor {
    public:
     void execute(const buffer_c8_t& buffer) override;
@@ -88,7 +91,7 @@ class NarrowbandFMAudio : public BasebandProcessor {
     bool pitch_rssi_enabled{false};
 
     float cur_sample{}, prev_sample{};
-    uint32_t z_acc{0}, z_timer{0}, z_count{0};
+    uint32_t z_acc{0}, z_timer{0}, z_count{0}, z_filter_count{0};
     bool ctcss_detect_enabled{true};
     static constexpr float k = 32768.0f;
     static constexpr float ki = 1.0f / k;