I've been playing with the G.R. at home testing it out with different size nuggets in the ground etc. First time out in the field with the Gold Racer yesterday. I was at a hydraulic pit in the area where the Scott River meets the Klamath River in Siskiyou county Ca. To get a stable threshold the settings were: Sensitivity 69, Threshold 35, iSat 3. The mineralization was 1 bar from max. The ground I started in was about 1/4" dirt over shale. The GR would lock hard at 99, the non-ferrous bar all the way to the right. I dug into the shale/Copper stained soil, kept checking the hole with GR then no more target. I checked the dug out material w/no target. Ok so I thought a glitch and kept swinging. Not more than 8 feet away and same target readings, same rusults. This happened three times . It was getting dark so decided to quit for the day. Steve or any other Gold Racer owners have any thoughts ?