diff --git a/YSFTX.cpp b/YSFTX.cpp
index dc209cc..b53684b 100644
--- a/YSFTX.cpp
+++ b/YSFTX.cpp
@@ -30,22 +30,22 @@ static q15_t YSF_C4FSK_FILTER[] = {688, -680, -2158, -3060, -2724, -775, 2684, 7
                                    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, 4, 'sqrt') in MATLAB
-static q15_t YSF_C4FSK_FILTER[] = {448, 0, -622, -954, -619, 349, 1391, 1704, 764, -1182, -3028, -3279, -861,
-                                   4135, 10280, 15335, 17288, 15335, 10280, 4135, -861, -3279, -3028, -1182,
-                                   764, 1704, 1391, 349, -619, -954, -622, 0, 448, 0};
-const uint16_t YSF_C4FSK_FILTER_LEN = 34U;
+// 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_HI[] = { 809,  809,  809,  809,  809};
-const q15_t YSF_LEVELB_HI[] = { 269,  269,  269,  269,  269};
-const q15_t YSF_LEVELC_HI[] = {-269, -269, -269, -269, -269};
-const q15_t YSF_LEVELD_HI[] = {-809, -809, -809, -809, -809};
+const q15_t YSF_LEVELA_HI[] = { 4035,  0,  0,  0,  0};
+const q15_t YSF_LEVELB_HI[] = { 1345,  0,  0,  0,  0};
+const q15_t YSF_LEVELC_HI[] = {-1345,  0,  0,  0,  0};
+const q15_t YSF_LEVELD_HI[] = {-4035,  0,  0,  0,  0};
 
-const q15_t YSF_LEVELA_LO[] = { 405,  405,  405,  405,  405};
-const q15_t YSF_LEVELB_LO[] = { 135,  135,  135,  135,  135};
-const q15_t YSF_LEVELC_LO[] = {-135, -135, -135, -135, -135};
-const q15_t YSF_LEVELD_LO[] = {-405, -405, -405, -405, -405};
+const q15_t YSF_LEVELA_LO[] = { 2019,  0,  0,  0,  0};
+const q15_t YSF_LEVELB_LO[] = {  673,  0,  0,  0,  0};
+const q15_t YSF_LEVELC_LO[] = { -673,  0,  0,  0,  0};
+const q15_t YSF_LEVELD_LO[] = {-2019,  0,  0,  0,  0};
 
 const uint8_t YSF_START_SYNC = 0x77U;
 const uint8_t YSF_END_SYNC   = 0xFFU;
@@ -143,7 +143,7 @@ void CYSFTX::writeByte(uint8_t c)
         break;
     }
   }
-
+    
   ::arm_fir_fast_q15(&m_modFilter, inBuffer, outBuffer, YSF_RADIO_SYMBOL_LENGTH * 4U);
 
   io.write(STATE_YSF, outBuffer, YSF_RADIO_SYMBOL_LENGTH * 4U);