I have hesitated posing about this discovery a fellow E-Trac user put me on to. However in conjunction with a discussion with another E-Trac user about why he's not finding indian head cents, it came up again and well, here's what I said to him:
"Combining the relic mode (with coins mode) really seems to help nickels come in better. (They hit harder and more solid.) Maybe adding (combining) one of the other modes would help on indians? Not sure. I believe the different modes work on different frequencies. The coin mode is set to be hot on silver - that's why it's a silver killer even in trash. This is why there is a separate mode for ferrous coins - the regular coin mode would stink on iron. Relic mode, you want brass, lead - lower conductors like nickel, so that totally makes sense that it is hotter on these (and maybe less hot on silver). Having said that, am I saying the E-Trac in coins mode might have a bias against nickel and lower conductive copper coins? Yep, I am. The E-Trac will kill silver, at the expense of lower conductive coins. I'm not saying the lower conductive coins aren't going to be detected, but their signals will be narrower and will not hit as hard as silver, so you have to work harder for them and go slow when you hit a hot spot."
"Combining the relic mode (with coins mode) really seems to help nickels come in better. (They hit harder and more solid.) Maybe adding (combining) one of the other modes would help on indians? Not sure. I believe the different modes work on different frequencies. The coin mode is set to be hot on silver - that's why it's a silver killer even in trash. This is why there is a separate mode for ferrous coins - the regular coin mode would stink on iron. Relic mode, you want brass, lead - lower conductors like nickel, so that totally makes sense that it is hotter on these (and maybe less hot on silver). Having said that, am I saying the E-Trac in coins mode might have a bias against nickel and lower conductive copper coins? Yep, I am. The E-Trac will kill silver, at the expense of lower conductive coins. I'm not saying the lower conductive coins aren't going to be detected, but their signals will be narrower and will not hit as hard as silver, so you have to work harder for them and go slow when you hit a hot spot."