Indoor phone book test bed. Go to the most open room in the house and turn off things that will cause electrical interference. Put your machine in the all metal mode a find the clearest place in the floor. Now...go get about a 8" to 10" thick stack of phone books and a couple of book markers. Grab a coin or two and some small junk or iron items. I'm sure you get the picture already. Place a coin and a junk item at different depth levels in the phone books and use book markers with targets to find them easy. Try this with as many combinations of depth and misalignment that you might encounter in the field. Pay close attention to what's going on with the audio and the meter. This is a great test to see how your detector will analyze these very common occurrences. Stagger the location of the test targets in the books and walk around a full circle swinging the coil over the books to get an idea of what the meter is doing under these conditions. Of course you will find that iron at one inch will give you a junk reading over a quarter at two inches but very seldom are the two objects in perfect vertical alignment. If you circle these objects swinging your coil, you will notice that the quarter will start to show up well at some point in your circle. My hunting buddy doesn't use headphones and I listen to his machine as well as my own. I just love going in behind him and digging up the coins that he thought were trash. He is so paranoid now, that if he sees me coming in behind him...he will start digging every sound he hears. Some times I do it now just to watch him work his butt off. I'm sure you old pros have done this years ago but it is sure to be some help to the new comer
.
.
