diff --git a/moc_test/gortlsdr/librtlsdr.c b/moc_test/gortlsdr/librtlsdr.c
index f67c30d..88c57ec 100644
--- a/moc_test/gortlsdr/librtlsdr.c
+++ b/moc_test/gortlsdr/librtlsdr.c
@@ -116,7 +116,7 @@ void do_init(void) {
 		.test_mode = 0,
 		.agc_mode = 0,
 		.direct_sampling_mode = 1,
-		.offset_tuning =1000,
+		.offset_tuning = 1,
 		.type = RTLSDR_TUNER_R828D,
 		.eeprom_buffer = {0x28, 0x32, 0x09, 0x01, 0x01, 0x01, 0xA5, 0x03,
 		0x1F, 0x03, 'R', 0x00, 'E', 0x00, 'A', 0x00, 'L', 0x00, 'T', 0x00, 'E', 0x00, 'K', 0x00,
@@ -141,7 +141,7 @@ void do_init(void) {
 		.test_mode = 1,
 		.agc_mode = 1,
 		.direct_sampling_mode = 0,
-		.offset_tuning =1001,
+		.offset_tuning = 0,
 		.type = RTLSDR_TUNER_R820T,
 		.eeprom_buffer = {0x28, 0x32, 0x09, 0x01, 0x01, 0x01, 0xA5, 0x03,
 		0x1F, 0x03, 'R', 0x00, 'E', 0x00, 'A', 0x00, 'L', 0x00, 'T', 0x00, 'E', 0x00, 'K', 0x00,
@@ -166,7 +166,7 @@ void do_init(void) {
 		.test_mode = 0,
 		.agc_mode = 1,
 		.direct_sampling_mode = 1,
-		.offset_tuning =1002,
+		.offset_tuning = 1,
 		.type = RTLSDR_TUNER_E4000,
 		.eeprom_buffer = {0x28, 0x32, 0x09, 0x01, 0x01, 0x01, 0xA5, 0x03,
 		0x1F, 0x03, 'R', 0x00, 'E', 0x00, 'A', 0x00, 'L', 0x00, 'T', 0x00, 'E', 0x00, 'K', 0x00,
@@ -424,10 +424,8 @@ int rtlsdr_get_direct_sampling(rtlsdr_dev_t *dev){
 }
 
 int rtlsdr_set_offset_tuning(rtlsdr_dev_t *dev, int on) {
-	if (!dev)
+	if (!dev || !dev_valid(dev))
 		return -1;
-	if (!dev_valid(dev))
-		return -2;
 
 	dev->offset_tuning = on;
 	return 0;
diff --git a/moc_test/main.go b/moc_test/main.go
index 3e4a1e3..4f30974 100644
--- a/moc_test/main.go
+++ b/moc_test/main.go
@@ -93,7 +93,7 @@ func SetFreqCorrection(d *rtl.Context, i int) {
 }
 
 func GetFreqCorrection(d *rtl.Context, i int) {
-	if ppm := d.GetFreqCorrection(); ppm != -1 {
+	if ppm := d.GetFreqCorrection(); ppm < 0 {
 		log.Printf("--- FAILED, GetFreqCorrection i:%d - %d\n", i, ppm)
 	} else {
 		log.Printf("--- PASSED, GetFreqCorrection i:%d\n", i)
@@ -168,7 +168,7 @@ func SetTunerGainMode(d *rtl.Context, i int) {
 }
 
 func SetSampleRate(d *rtl.Context, i int) {
-	rateHz := 3500000
+	rateHz := 225001
 	if err := d.SetSampleRate(rateHz); err != nil {
 		log.Printf("--- FAILED, SetSampleRate i:%d - %s\n", i, err)
 	} else {
@@ -272,17 +272,17 @@ func main() {
 
 	for i := 0; i < cnt; i++ {
 		if len(GetDeviceName(i)) == 0 {
-			log.Printf("--- FAILED, GetDeviceName i:%d\n")
+			log.Printf("--- FAILED, GetDeviceName i:%d\n", i)
 		} else {
-			log.Printf("--- PASSED, GetDeviceName i:%d\n")
+			log.Printf("--- PASSED, GetDeviceName i:%d\n", i)
 		}
 	}
 
 	for i := 3; i < 6; i++ {
 		if len(GetDeviceName(i)) != 0 {
-			log.Printf("--- FAILED, GetDeviceName i:%d\n")
+			log.Printf("--- FAILED, GetDeviceName i:%d\n", i)
 		} else {
-			log.Printf("--- PASSED, GetDeviceName i:%d\n")
+			log.Printf("--- PASSED, GetDeviceName i:%d\n", i)
 		}
 	}
 
@@ -292,7 +292,7 @@ func main() {
 			log.Printf("--- FAILED, GetDeviceUsbStrings i:%d, %s\n", i, err)
 		} else {
 			serials = append(serials, s)
-			log.Printf("--- PASSED, GetDeviceUsbStrings i:%d\n")
+			log.Printf("--- PASSED, GetDeviceUsbStrings i:%d\n", i)
 		}
 	}
 
@@ -300,7 +300,7 @@ func main() {
 		if _, _, _, err := GetDeviceUsbStrings(i); err == nil {
 			log.Printf("--- FAILED, GetDeviceUsbStrings i:%d, %s\n", i, err)
 		} else {
-			log.Printf("--- PASSED, GetDeviceUsbStrings i:%d\n")
+			log.Printf("--- PASSED, GetDeviceUsbStrings i:%d\n", i)
 		}
 	}