diff --git a/cubesatsim/cubesatsim.ino b/cubesatsim/cubesatsim.ino
index 467adba0..81c707e0 100644
--- a/cubesatsim/cubesatsim.ino
+++ b/cubesatsim/cubesatsim.ino
@@ -480,7 +480,7 @@ void send_aprs_packet() {
 }
 
 void send_cw() {
-// if (filter_present) 
+ if (filter_present) 
  { // only transmit CW packet if BPF filter is present
 	
   char de[] = " DE ";