Check your new ENDEC units. If the s/n starts with B4, you're good. If it starts with B3, hook a decent sized wire from one of the 3 terminals marked GND to the frame of the ENDEC and the frame of the EAS receiver chassis. They designed it with a floating audio ground that screams Hit Me right up there with the best James Brown records. That should be adequate. If you have one that begins with B2, it has an even bigger vulnerability...I haven't dealt with one of those yet. Worth a call to Sage if you have a B2.