Good reminder.
Some guys, in particular beach hunters, will stick a nickel in the tip of their shoe so they can sweep over it to remind themself how nickel signals sound while looking for rings with their Excalibur or GT. Only thing is that IMO no more gold rings read in the nickel zone than any other zone. More read in the foil range than in the nickel or tab range combined from what our numbers scanning in over 100 random gold rings say, and these rings weren't biased by people only digging certain targets. Everything above iron was scooped by an Excal hunter water hunting over several years.
I think the reason that old saying of "dig the nickel zone to find gold rings" came about on detectors is from machines with far less resolution in the low to mid conductivity range than the 180 meter on the Sovereign. Other machines have wider nickel zones and so have more lower conductivity foil and higher conductivity tabs stuffed in the same zone or VDI # range, so of course a lot more gold rings would be in the nickel zone because it's wider.
But the tip is still a good one to say avoid higher sounding tabs when you don't have the time to scoop them for a hunt and they are all over the place, or also to hear how a round object like a nickel or a gold ring has a nice smooth round sound to them compared to some junk, especially odd shaped junk.