diff --git a/Config.h b/Config.h
index 9c3809c..f594cf0 100644
--- a/Config.h
+++ b/Config.h
@@ -43,5 +43,10 @@
 // For the SP8NTH board
 // #define  ARDUINO_DUE_NTH
 
+// To use wider C4FSK filters for DMR and System Fusion on transmit
+// #define WIDE_C4FSK_FILTERS_TX
+// To use wider C4FSK filters for DMR and System Fusion on receive
+// #define WIDE_C4FSK_FILTERS_RX
+
 #endif
 
diff --git a/DMRTX.cpp b/DMRTX.cpp
index 7430d68..9151341 100644
--- a/DMRTX.cpp
+++ b/DMRTX.cpp
@@ -23,10 +23,18 @@
 #include "Globals.h"
 #include "DMRSlotType.h"
 
+#if defined(WIDE_C4FSK_FILTERS_TX)
 // Generated using rcosdesign(0.2, 4, 5, 'sqrt') in MATLAB
 static q15_t DMR_C4FSK_FILTER[] = {688, -680, -2158, -3060, -2724, -775, 2684, 7041, 11310, 14425, 15565, 14425,
                                    11310, 7041, 2684, -775, -2724, -3060, -2158, -680, 688, 0};
 const uint16_t DMR_C4FSK_FILTER_LEN = 22U;
+#else
+// Generated using rcosdesign(0.2, 8, 5, 'sqrt') in MATLAB
+static q15_t DMR_C4FSK_FILTER[] = {401, 104, -340, -731, -847, -553, 112, 909, 1472, 1450, 683, -675, -2144, -3040, -2706, -770, 2667, 6995,
+                                   11237, 14331, 15464, 14331, 11237, 6995, 2667, -770, -2706, -3040, -2144, -675, 683, 1450, 1472, 909, 112,
+                                   -553, -847, -731, -340, 104, 401, 0};
+const uint16_t DMR_C4FSK_FILTER_LEN = 42U;
+#endif
 
 const q15_t DMR_LEVELA[] = { 640,  640 , 640,  640,  640};
 const q15_t DMR_LEVELB[] = { 213,  213,  213,  213,  213};
diff --git a/DStarTX.cpp b/DStarTX.cpp
index 1456bc0..7411b81 100644
--- a/DStarTX.cpp
+++ b/DStarTX.cpp
@@ -289,8 +289,10 @@ uint8_t CDStarTX::writeHeader(const uint8_t* header, uint8_t length)
     return 4U;
 
   uint16_t space = m_buffer.getSpace();
-  if (space < (DSTAR_HEADER_LENGTH_BYTES + 1U))
+  if (space < (DSTAR_HEADER_LENGTH_BYTES + 1U)) {
+    DEBUG2("D-Star, header space available", space);
     return 5U;
+  }
 
   m_buffer.put(DSTAR_HEADER);
 
@@ -307,7 +309,7 @@ uint8_t CDStarTX::writeData(const uint8_t* data, uint8_t length)
 
   uint16_t space = m_buffer.getSpace();
   if (space < (DSTAR_DATA_LENGTH_BYTES + 1U)) {
-    DEBUG2("D-Star, space available", space);
+    DEBUG2("D-Star, data space available", space);
     return 5U;
   }
 
@@ -322,8 +324,10 @@ uint8_t CDStarTX::writeData(const uint8_t* data, uint8_t length)
 uint8_t CDStarTX::writeEOT()
 {
   uint16_t space = m_buffer.getSpace();
-  if (space < 1U)
+  if (space < 1U) {
+    DEBUG2("D-Star, EOT space available", space);
     return 5U;
+  }
 
   m_buffer.put(DSTAR_EOT);
 
diff --git a/IO.cpp b/IO.cpp
index d3b61fc..ce98e1b 100644
--- a/IO.cpp
+++ b/IO.cpp
@@ -24,10 +24,18 @@
 #include "Globals.h"
 #include "IO.h"
 
+#if defined(WIDE_C4FSK_FILTERS_RX)
 // Generated using rcosdesign(0.2, 4, 5, 'sqrt') in MATLAB
 static q15_t C4FSK_FILTER[] = {688, -680, -2158, -3060, -2724, -775, 2684, 7041, 11310, 14425, 15565, 14425,
                                    11310, 7041, 2684, -775, -2724, -3060, -2158, -680, 688, 0};
 const uint16_t C4FSK_FILTER_LEN = 22U;
+#else
+// Generated using rcosdesign(0.2, 8, 5, 'sqrt') in MATLAB
+static q15_t C4FSK_FILTER[] = {401, 104, -340, -731, -847, -553, 112, 909, 1472, 1450, 683, -675, -2144, -3040, -2706, -770, 2667, 6995,
+                                   11237, 14331, 15464, 14331, 11237, 6995, 2667, -770, -2706, -3040, -2144, -675, 683, 1450, 1472, 909, 112,
+                                   -553, -847, -731, -340, 104, 401, 0};
+const uint16_t C4FSK_FILTER_LEN = 42U;
+#endif
 
 // Generated using gaussfir(0.5, 4, 5) in MATLAB
 static q15_t   GMSK_FILTER[] = {8, 104, 760, 3158, 7421, 9866, 7421, 3158, 760, 104, 8, 0};
diff --git a/YSFTX.cpp b/YSFTX.cpp
index cb56672..fa616a4 100644
--- a/YSFTX.cpp
+++ b/YSFTX.cpp
@@ -24,10 +24,18 @@
 
 #include "YSFDefines.h"
 
+#if defined(WIDE_C4FSK_FILTERS_TX)
 // Generated using rcosdesign(0.2, 4, 5, 'sqrt') in MATLAB
 static q15_t YSF_C4FSK_FILTER[] = {688, -680, -2158, -3060, -2724, -775, 2684, 7041, 11310, 14425, 15565, 14425,
                                    11310, 7041, 2684, -775, -2724, -3060, -2158, -680, 688, 0};
 const uint16_t YSF_C4FSK_FILTER_LEN = 22U;
+#else
+// Generated using rcosdesign(0.2, 8, 5, 'sqrt') in MATLAB
+static q15_t YSF_C4FSK_FILTER[] = {401, 104, -340, -731, -847, -553, 112, 909, 1472, 1450, 683, -675, -2144, -3040, -2706, -770, 2667, 6995,
+                                   11237, 14331, 15464, 14331, 11237, 6995, 2667, -770, -2706, -3040, -2144, -675, 683, 1450, 1472, 909, 112,
+                                   -553, -847, -731, -340, 104, 401, 0};
+const uint16_t YSF_C4FSK_FILTER_LEN = 42U;
+#endif
 
 const q15_t YSF_LEVELA[] = { 809,  809,  809,  809,  809};
 const q15_t YSF_LEVELB[] = { 269,  269,  269,  269,  269};