I have been using my etrac for probably two months now and thats almost everyday with alot of 8-10 hour days and ive read Andys book twice. Hunting for civil war relics in camps and such. I either use TTF or wide open 4 tone to hear everything. Here is what i have learned so far. First thing being that if a brass button or minie ball are over 6 inches deep the ID numbers arent even in the ball park of what they should be and this is in east tennessee with good soil.. Next is that in camps with alot of square nails and iron,the etrac will latch on to an iron signal and never even here the brass or minie ball close to it and i know this because my brother went over a 20ftx20ft area i hunted sunday with his AT pro and found 5 minie balls and 2 eagle buttons and the worst part is that most of em were next to holes i had dug and pulled out square nails. I always go back over holes i dig and in that area it would just audio the iron so i would move on.Needless to say i am very disappointed on the etracs performance when relic hunting. I researched and researched before i bought it and thought id be happy with it but unfortunately its not the machine i thought itd be but it must be a great coin machine because i see alot of u guys posting awesome finds on coins.Anyway,thats just my observation on civil war relic hunting with it and i am gonna keep trying with it but i think ive pretty much seen what it can do. God bless everyone and happy hunting