WHY CAN'T ANY OF THE MAJOR DETECTOR MAKERS FIGURE THIS OUT, HOW TO TOTALLY DISCRIMINATE RINGS FROM PULLTABS! HAPPY HUNTING CHRIS
Rings and pulltabs are one and the same, electrically. You should be grateful for this fact, in fact. This whole discrimnination thing is easy to figure out, and to answer your question Chris, the many makers already have. Here's the result:
There is no magic bullet. The Laws of Electro-physics are immutable.
Metal is metal; its just what it is. To be really useful it is refined, amalgamated and alloyed. Then it is made into more things than you or I can count. Some of it is valuable, fiscally speaking, while some of it has other uses that make it worthy, in one way or another.
Jewelry metals can be anywhere on an electrophysic "scale of conductivity," from below nickle range to solid coin, depending on their composition, configuration or proximity to other metallic items. I found a gold charm last fall that wouldn't hit solid in foil range and more than a few rings that have come through loud and clear like coins.
These things are not revelations or new; you've probably heard them many times before. But, discrimination, while not perfect, is your greatest friend. Every old timer knows this and understands it's real benefit: its ability to differentiate iron. You read that right - iron. NOT pulltabs, foil and other junk.
Iron is, and has been, the most common metal of man for a very long time... and only until recently the most worthless to our greedy eyes. However, it too, has it's uses. It's a harbinger of former usage and thus potential value on sites. In other words, find old iron and you know you have a potentially good site.
It may come as a surprise to know that discrimination based on electromagnetic phase realtionship was first created as a way to IDENTIFY iron, not eliminate it. The earliest detectors had no discrimination and so found everything. Hobbyists at the time knew that the best thing was to be able to ID ferrous targets - then decide to dig or not. Some very nice and even valuable iron relics have been found over the years, simply because the information was there to base a decision upon
Aluminium came later in profusion, and while good for holding beer - it's highest calling, I might add - it, too, fits into it's place in the spectrum of conductivity. It just so happens that it and the sundry other "junk metals" are in the same general range as those items we deem valuable. Sheer happenstance, as it were.
It's not whether they are in a ring shape or not, although some of them are. It's ONLY that they conduct electricity and upset an electrical field the same as some other things - in this case rings and jewelry. There is little to be done about this - so you have to work with that. It's more about attitude...YOURS.
Consider it this way:
A target is either - - -
- Low range. This includes the ferrous items and small foils, due to the way they refract the signals induced in them by the emitter. This range is easy to identify so even todays basic detector can DISC this stuff. We are lucky for that, by the way.
- Mid range. This is where nickles, tabs, canslaw, screwcaps and most gold alloys land. Believe it or not, manufacturers have come a loooooong way in opening this range up - giving us more information about the items that fall in the scale here than ever before.
- High range. This is the territory of our beloved silver and other highly conductive metals. It is also easy to identify. Coins, some jewelry, copper, brass, pot metals and others land here. I daresay I have found scads of items that rang out as high range that were NOT coins or other valued items.
As you;ve noted, it is the midrange that causes us the most grief, for even a high-range junk item, say a good sounding electrical connector, has some "value" - not so, a wad of midrange canslaw! It is OUR perception of these things that is at the heart of the matter, not a detectors ability to differentiate something.
However, as long as the "good stuff" shares the same range as the crap, we will be forced to dig junk. It's how you view all this that matters. An accomplished detectorist learns to view his chosen machines response as one of the three range-options mentioned above and nothing more. I mean that implicitly: NOTHING MORE.
He's not swinging his machine waiting to be told when or when not to dig. He's on-site to learn that something IS there, to DETECT in other words. He knows the next step is RECOVERY, not walking on by. Exercise is only a side benefit of this pastime.
This is why I like tone ID detectors. I dont use the audio tones to tell me what NOT to dig, but merely as a way to tell me where an item falls on the scale without having to look at a display. Then I only have to judge repeatability and solidity of the signal. "If it will repeat in one direction and can be distinguished on it's own... DIG."
I'm sure you've heard that said, in one way or another - for good reason. It's all you really need to know.
I notice John B. (Edmonton) has begun showing more and more of the junk he recovers. He is one of the best and most accomplished detectorists around here (or anywhere, for that matter) and there is something to be learned when he does a thing. I suggest all of us will do more and go farther if we accept these things. In fact, you may want to begin developing a perverse pride in the amount of junk you recover, hereafter.
