Hi Mick,
I've just re-read the article myself. I thnk the $2 you're referring to is the one that was discoloured (grey). This was found in Tamworth, in an area which is well tramped. The soil in this area has the effect on coins that have been buried for some time in that they come in on the disc. scale considerably lower than you would expect. i.e. a $2 comes in round about the 20c mark. I've verified this several times with different detectors .e.g. my Tesoro Eldorado and my Minelab Explorer II (when I had it). So, anyone detecting with disc. set to knock out anything below $2 would either get no signal or a very iffy one. From memory, this $2 gave a good solid signal (as did the $1 which was under the pulltab, mentioned in the article. Finding that $1 really made me aware as to how good the Cibola is). I took it to Newcastle one weekend when I took my daughter down there, and found many $2 coins which were all down 4" to 6" in the soil, below grass. I dont know whether these were too deep for whoever detects there, or just didn't signal well enough to worry about, but there were definite signs that someone else detected in the area where I was. If you dont want to worry about gold too much, there is a setting on the Cibola which basically knocks out all pulltabs, but still signals on 50c, $1 and $2, silver rings and pre-decimals that come in above the 50c range. As I said, the Cibola is something special (my daughter found her first silver ring with mine, at the beach). I remember one occasion I took the Cibola to the beach, and in one small spot found half a dozen or so coins, all at good depth..it was winter. The next day, a fellow was detecting in the same spot with his Sovereign with a 15" WOT. I had been talking to him earlier, and when he was leaving the same small area I had detected the day before, I asked him if he had found anything (as I had seen him digging a bit). "Only junk" was his reply, and his demeanour backed it up. I was only curious as to whether the Cibola missed anything, & whether ther was something deeper that the sovereign might find, but evidently the Cibola had done a pretty good job. I was using the 9x8 concentric coil. If you're looking for a non-metered machine, you could do a lot worse. No frills, sheer power. All the Best.