diff --git a/transmit.py b/transmit.py
index 01586a64..2bb7f7b1 100644
--- a/transmit.py
+++ b/transmit.py
@@ -620,9 +620,13 @@ def cw_transmit_char(character):
 def transmit_carrier(duration):
 	global tx_doppler_freq_hz
 	global txLed
-	command = "timeout " + str(duration) + " sudo tune -f " + str(tx_doppler_freq_hz) + " > /dev/null 2>&1" # 434.9e6
+#	command = "timeout " + str(duration) + " sudo tune -f " + str(tx_doppler_freq_hz) + " > /dev/null 2>&1" # 434.9e6
+	start = "sudo tune -f " + str(tx_doppler_freq_hz) + " > /dev/null 2>&1" # 434.9e6
+	stop = "sudo killall -9 tune"
 	output(txLed, 1)
-	system(command)
+	system(start)
+	sleep(duration)
+	system(stop)
 	output(txLed, 0)
 
 print("CubeSatSim v2.2 transmit.py starting...")