This was written by a guy hunting in Culpepper.
The red dirt areas are pretty tough for any VLF detector to handle. The ground itself has a heavy iron oxide to it; thus the reddish color. The shallower items in the ground can be hit pretty well with VLFs, with the cut off limit about 5 inches deep.
If you are running in disc mode and have it set above iron, that's where the bad stuff starts. The detector sees EVERYTHING in the ground as iron so it is knocking the good targets out and you never know they are down there.
Use All Metal. FOR THE MOST PART, you will hear the signal but on an ID machine, it is going to still read as iron. The preset Relic mode is a good place to start. Put your Search Audio in All Metal Mode. Then you can increase your All Metal sensitivity/gain to where the unit is stable. The next thing is put it in single frequency mode. I found the single frequency of 7.5 to give the best target response. Put it in manual ground balance.
Change the Recovery speed rate to a setting of 40, the Recovery rate of 40 gives a very fast double blip that makes a nail easy to distinguish. I noticed when I'd get a good solid sounding signal that didn't double blip...that if you swung the coil over it multiple times sizing it up, that the detector would average it out. I was actually doing very well digging Civil War bullets down to about 11-12 inches.
The red dirt areas are pretty tough for any VLF detector to handle. The ground itself has a heavy iron oxide to it; thus the reddish color. The shallower items in the ground can be hit pretty well with VLFs, with the cut off limit about 5 inches deep.
If you are running in disc mode and have it set above iron, that's where the bad stuff starts. The detector sees EVERYTHING in the ground as iron so it is knocking the good targets out and you never know they are down there.
Use All Metal. FOR THE MOST PART, you will hear the signal but on an ID machine, it is going to still read as iron. The preset Relic mode is a good place to start. Put your Search Audio in All Metal Mode. Then you can increase your All Metal sensitivity/gain to where the unit is stable. The next thing is put it in single frequency mode. I found the single frequency of 7.5 to give the best target response. Put it in manual ground balance.
Change the Recovery speed rate to a setting of 40, the Recovery rate of 40 gives a very fast double blip that makes a nail easy to distinguish. I noticed when I'd get a good solid sounding signal that didn't double blip...that if you swung the coil over it multiple times sizing it up, that the detector would average it out. I was actually doing very well digging Civil War bullets down to about 11-12 inches.