Overall the buzz in the online forums is that while the E-Trac is a silver slayer, it is weak (but not useless) on nickels (and theoretically gold). My impression is that this is true. Air testing
What I wanted to get at is:
a) Am I doing something wrong?
b) Can I do something better/differently?
c) Are there nickels here and I am passing them up because they don't sound like I think a nickel should?
d) Are there just very few or no old nickels in my sites?
So, I figured I would try an experiment to up my nickel count, and specifically check some areas where I had been finding deep older coins (many wheats) for some buffalo or V nickels.
The particular park I went to has been generous with older coins 1920-1970, but is also loaded with pull tabs. I'm not worried about the COs in the 20's so much that "could" be nickel 3 cents or fatty Indian cents, or other coins. The most likely targets here are going to be worn V nickels, buffalo and Jefferson nickels. Seriously, I could dig pull tabs forever out of this place, so "dig all" is a crazy proposition, unless I decide to start collecting pull tabs. And if you do like collecting pull tabs the graphic I have attached may be of some interest. Also, many may not be aware that the first pulltabs came out in 1962 and had a rather unique shape. If you want to read more about those, look here http://www.rustycans.com/HISTORY/zips.html
So, went out to try it out for about an hour before the rain came. Looking for repeatable hits in that nickel window. Scratchy partial signals were not considered for this experiment. Dug a lot of one piece ring pull tabs (ironically stamped "Don't Litter" - circled in red on graphic at bottom), tails from two piece ring tabs, assorted other tabs, some foil and four newer nickels. The newer nickels were 2-3" deep and red colored, so they were not new drops, and had been in the ground a while. What I noticed was that the nickel signals that were nickels, when pinpointed and then swept over that "center" - all gave me a relatively repeatable signal at CO 13 that the junk tended not to. The coin signals were a bit smoother, but not enough that I could clearly call them out.
1) Other detectors (now or in the past) were hot on nickles (vs. tabs) at the heavily hunted sites I am at (i.e. there are not many old nickels left there) I know I dug quite a few old nickels in these places with my Fisher CZs and they were hot nickel machines.
2) The Minelab nickel window is tight... CO 13 seemed to be a magic number, but you had to be right on it for the most part to get a nice repeatable CO 13. If you were a little off center, it bounced around enough that I would probably pass it up as junk. (That said, I have dug old nickels that were not solid CO 13s but smoother deeper signals that just said "dig me" to my ears.)
3) Does the halo/leaching of old nickels possibly make them read lower or higher? Perhaps more like iron? This was my suspicion, but I have no evidence either way. Would I theoretically then find more old nickels in dry soil conditions? This did not prove itself to be true this summer.
4) My friend with an E-Trac says when he first got the E-Trac he used Relic mode and dug more nickels. He's since switched to Coin mode and reports his nickel count has dropped off from when he was using Relic mode.
Would opening the FE all the way from top to bottom for 12-13-14 result in more nickels? Is the FE value of nickels the trick? That would explain my friend's result with using Relic mode. It would also tend to support my supposition that the nickel "halo" is causing the nickels to read lower than FE 12 and more like/closer to iron. This will be by next experiment... which will be covered in Part 2.