Are your batteries fresh? You might try putting the receiver in a little different location and see if it will receive the signal there. I had to replace two last summer that had been running constantly for 5 years with no problems, but they just sort of died. I would probably go with the type that 6mm06 recommends if I was ordering new ones now. Hopefully he will try the distance they will receive and let us know when he gets a break from the coyote killing.