Jackindistress,
I've been looking at the MURS with some interest too. Just wondering how they will work for small animals down to the size of skunk. Any idea? It would be a good investment for the long run if it works as intended. So many of the motion detectors are designed for people and automobiles, so I want to find one that will work well for coyotes.
Here's another alert that I found this evening. Heard any reports on this one?
http://www.sportsmansguide.com/net/cb/cb.aspx?a=470404
Also, I have been using your method too of putting out just enough bait to keep them coming, small cuts scattered about. Meat lasts longer that way and also keeps activity going.