I took an hour of this afternoon to get some practice with the Lobo ST and the new concentric coil that I purchased. I have a lot of questions and with experience maybe I will solve them. The are is an amphitheater where once a year the locals put on a pageant. The seats are aluminum and there are several aluminum conduits buried as I found out. These cause a lot of interference. Gravel is used as fill between the seats and it contains hematitic sandstone pieces. The mother soil is alkali rich, so I experimented with the GB and found that the alkali worked better in all metal mode. I don't think it mattered in discriminate mode. Pin pointing using discriminate mode was a bear (maybe that is why there is a pin point function). I set the sensitivity to 6 and discriminate at 3 and it was like listening to a bad concert (noise everywhere). I finally turned the des to 9 and found a dime and a penny. I did learn that the Lobo is very sensitive and the coil I am not sure about. Granted it wasn't the best place to experiment but the snow is melting and I will be out in greener pastures soon. Any advise would be well accepted.