i got a at pro as my first detector and have found some nice old coins 1912 v nickel,1912 barber dime 1942 and 45 merc dimes and many wheat Penny's which all just blew my mind never thought i would find anything like that took awhile to learn but with help form the folks here the learning curve was much shorter thank you for the help,but I've read some people send their machines in for up dates ,is this something that should be done every year and should it be done when you get new coils or smaller coils,i got the 8x5 and herd you need to get up grades for different coils other then the coil that machine comes with