diff --git a/cubesatsim/cubesatsim.ino b/cubesatsim/cubesatsim.ino
index 3034cf1e..b537666e 100644
--- a/cubesatsim/cubesatsim.ino
+++ b/cubesatsim/cubesatsim.ino
@@ -2233,7 +2233,8 @@ void config_radio()
     if (sr_frs_present)
       digitalWrite(PD_PIN, HIGH);  // Enable SR_FRS
     else {
-     start_clockgen();
+     if (!clockgen_present)	    
+       start_clockgen();
      if (clockgen_present) {	    
       if (clockgen.setClockFSK(frequency_offset)) {	  
 	 start_clockgen();