diff --git a/src/energenie/drv/hrfm69.h b/src/energenie/drv/hrfm69.h
index ea27e73..253dfa9 100644
--- a/src/energenie/drv/hrfm69.h
+++ b/src/energenie/drv/hrfm69.h
@@ -93,8 +93,10 @@
 #define HRF_VAL_PREAMBLELSB3           0x03	// preamble size LSB 3
 #define HRF_VAL_PREAMBLELSB5           0x05	// preamble size LSB 5
 #define HRF_VAL_SYNCCONFIG0            0x00     // sync word disabled
-#define HRF_VAL_SYNCCONFIG2            0x88	// Size of the Synch word = 2 (SyncSize + 1)
-#define HRF_VAL_SYNCCONFIG4            0x98	// Size of the Synch word = 4 (SyncSize + 1)
+#define HRF_VAL_SYNCCONFIG1            0x80     // 1 byte  of tx sync
+#define HRF_VAL_SYNCCONFIG2            0x88	// 2 bytes of tx sync
+#define HRF_VAL_SYNCCONFIG3            0x90     // 3 bytes of tx sync
+#define HRF_VAL_SYNCCONFIG4            0x98	// 4 bytes of tx sync
 #define HRF_VAL_PAYLOADLEN255          0xFF	// max Length in RX, not used in Tx
 #define HRF_VAL_PAYLOADLEN66           66	// max Length in RX, not used in Tx
 #define HRF_VAL_FIFOTHRESH1            0x81	// Condition to start packet transmission: at least one byte in FIFO
diff --git a/src/energenie/drv/hrfm69_test.c b/src/energenie/drv/hrfm69_test.c
index b7c3bb6..452a3f3 100644
--- a/src/energenie/drv/hrfm69_test.c
+++ b/src/energenie/drv/hrfm69_test.c
@@ -79,6 +79,10 @@
     uint8_t rv = read_ver();
     TRACE_OUTN(rv);
     TRACE_NL();
+    if (rv != 36)
+    {
+        TRACE_FAIL("unexpected radio ver, not 36(dec)\n");
+    }
 
     TRACE_OUTS("testing...\n");
     hrf_test_send_ook_tone();
@@ -121,14 +125,14 @@
     {HRF_ADDR_BITRATEMSB, 	  0x1A},                         // 4800b/s
     {HRF_ADDR_BITRATELSB,         0x0B},                         // 4800b/s
     {HRF_ADDR_PREAMBLELSB, 	  0},                            // preamble size LSB 0
-    {HRF_ADDR_SYNCCONFIG, 	  HRF_VAL_SYNCCONFIG4},		 // Size of the Sync word
-    {HRF_ADDR_SYNCVALUE1,         0x80},
-    {HRF_ADDR_SYNCVALUE2,         0x00},
-    {HRF_ADDR_SYNCVALUE3,         0x00},
-    {HRF_ADDR_SYNCVALUE4,         0x00}, 
+    {HRF_ADDR_SYNCCONFIG, 	  HRF_VAL_SYNCCONFIG0},		 // Size of the Sync word
+    //{HRF_ADDR_SYNCVALUE1,         0x81},
+    //{HRF_ADDR_SYNCVALUE2,         0x00},
+    //{HRF_ADDR_SYNCVALUE3,         0x00},
+    //{HRF_ADDR_SYNCVALUE4,         0x00}, 
     {HRF_ADDR_PACKETCONFIG1,      0x00},	                 // Fixed length, no Manchester coding
-    {HRF_ADDR_PAYLOADLEN, 	  8},	                         // Payload Length
-    {HRF_ADDR_FIFOTHRESH, 	  7}                             // Condition to start packet transmission: exceeds 7 bytes in FIFO
+    {HRF_ADDR_PAYLOADLEN, 	  2},	                         // Payload Length
+    {HRF_ADDR_FIFOTHRESH, 	  1}                             // Condition to start packet transmission: exceeds 7 bytes in FIFO
 };
 #define CONFIG_OOK_COUNT (sizeof(config_OOK)/sizeof(HRF_CONFIG_REC))
 
@@ -163,7 +167,7 @@
 
     /* A regular tone */
     static uint8_t payload[] = {
-        0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA
+        0x81, 0x00 //0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA
     };
 
     while (1)