Hi Charlie,
I am not sure what type of detector you are referring to, but I found gold coins to be much less conductive than silver or copper.
It has been quite a while since I tested them but if I remember correctly, a $5 gold coin read in the nickel to pull tab range on a TID motion detector. A $10 gold coin read higher, somewhere in the screw cap range, if I remember correctly.
Gold by nature is less conductive than silver and copper. If you do a search on the net for metal conductivities, you will get varied results, but all will clearly show that gold is less conductive than silver or copper. Gold is used in electronics, not for its conductivity, but for its inert properties. It simply doesn't corrode. As such, contacts or connections will remain good even in hostile conditions.
A nickel and a $5 gold coin are fairly close to the same size and are detected about the same. A 1/4 oz nugget will also TID about the same. At least they did the last time I checked.
So, to answer your question about a nickel and gold, yes, if a detector does well on nickels, then it should do well on gold coins also. Gold nuggets are a different story. Larger nuggets can vary considerably due to several factors. Smaller nuggets require a detector sensitive enough to detect them. On a VLF, this generally requires a detector operating at a higher frequency, or with a PI, having a very short delay before sampling. The smaller the nugget, the more important the delay or operating frequency become.
Reg
Although this is a PI forum, I will dwell on a little hirtory about a VLF detector built by Garret, called the Groundhog. Originally built as a coin hunting detector, this machine became very popular as a gold hunting machine. The detector sucked on silver and copper but loved nickels. At least, mine did.
Reg
