Nick, you say you read of "
several users commenting that tabs read differently from gold"
Funny, but I KNEW, when this machine came out, that claims like this would be put forth. It was no different than when the Spectrum (and XLT, etc...) first came out: Persons mused if they could *finally* pass aluminum in favor of gold. Ie.: they reasoned that if they studied the peaks and smears and bars long enough, that there *must* be a difference between foil wads, beaver tails, tabs, and gold. There is even a dealer that makes such claims! ("gold sounds different than aluminum"). A pity the poor newbie who believes this, and goes out knocking himself silly thinking "oh gee, I wish I was that smart, I guess I need XX years more experience to finally 'get it' "
Sure: If you tested a series of tabs and foil wads, and then tested a gold ring, I gaurantee you: the gold ring will measure differently (on the graphs and such) than ALL your sampled aluminum. But SO TOO does each gold ring read differently than each other too! And I gaurantee you that for each gold ring you sample, that I can, given enough time, wad up a ball of foil or bend up a piece of aluminum, in *just* the right way to exactly mimic your gold ring.
The reason people *think* that gold and aluminum read/sound differently, is selective memory. It works like this: each time you/we stop to dig a low conductive target, we look at the graphs, listen to the sounds, and think "aha, this sounds/looks different". But when it turns out to be junk, we forget our premonitions, and say to ourselves "yeah, you know, it did sound kind of junk, now that I think of it". But when we FINALLY dig a gold ring, we only THEN remember our "it sounds/looks different" premonitions, and think "aha! I
knew it sounded different!" It's the same psychology for thinking our dreams at night come true the next day: we dream hundreds of random dreams, none of which come true, so we immediately forget them the next morning. But when one coincidentally comes true, THEN we remember the dream, and think "aha! I'm psychic!" It's the same psychology for gold vs aluminum.
Here's what I would suggest, the next time you read someone on a forum tell you that this, or any machine, can tell aluminum vs gold (whether by graphs, sounds, or whatever): Immediately challenge them to go to the nearest inner-city-blighted urban trashy park, and see how long they stick their claims