Went out for a while a few days ago and messed around with TTF and conductive mode at a big park. Found a silver quarter that was a really iffy signal one way so did some experimenting with TTF and conductive on the signal. I think there was some trash mixed in. Also got a few small silvers.
http://www.youtube.com/watch?v=Nl7WlmVo7Fg
http://www.youtube.com/watch?v=Nl7WlmVo7Fg