I have a Radio Shack Pro 106 police scanner. Weird issue going on. The scanner works fine on regular alkaline batteries. When I take the battery pack out and plug the dc power outlet into cig lighter it powers up and scans as normal. The issue is that even though its scanning as normal no transmissions come through. I disconnect the dc and put the batteries back in it's normal operation again with all the usual transmissions coming through. Ever heard of this or have suggestions? I hate to use batteries when I can simply plug up to dc. Thank you. Jerry