I am not familiar with the 705 but I know a little about gold detectors. Coin machines are not the best at finding small-to-tiny gold. PI machines are the most effective but pretty pricey. There are vlf gold machines that might be best for you at a mid-price ($600-800). Among those are the White's GMT, Fisher Gold Bug 2. They have frequencies that range from 48 khz to 60 kzh. Most gold is very small and high frequencies are best for that plus they will also find bigger nuggets.