Welcome to the Explorer World, dedicated to cleansing the world of all lost buried coins. Simply stated, the Explorer has two separate adjustable channels of discrimination, each with its own screen, and you have the ability to rapidly switch from one to the other. One, the "smart" screen, is totally programmable in many different ways using factory programs set to find certain groups of items (i.e., coins, jewelry...)and discriminate out the unwanted junk, or totally programmable by you in various ways (the book is quite clear on this and there have been lots of posts on various programs if you explore earlier posts on this forum). This channel or screen is basically like all the discrimination screensand circuits on most other detectors, the ones you are used to. The IRON MASK channel and screen is also a discrimination circuit but is not programmed the same way nor are levels set the same way by the user; it is much more limited and specific. You can duplicate EXACTLY what the iron mask screen does on your smart screen channel, but not vice-versa. Iron mask is just a quick way to set varying levels of discriminating out low to high levels of iron-type signals- from iron and other items that "sound" like iron (which can include some gold rings and really deep coins). Think of it as a typical detector discrimination circuit, but instead of being able to turn the discrimination knob to progressively knock out iron, foil, tabs, zinc pennies etc- it only turns within the iron range and stops, goes no higher. Your smart screen of course goes everywhere.
Why have a separate iron mask circuit and screen? There are two basic uses for it. One is to HUNT in the iron mask mode. If you hunt in a totally blank iron mask screen you are basically hunting in a motion all-metal mode (the Explorer does not have a non-motion all metal mode other than pinpoint, which is not a mode you can really hunt in). This is great for beach hunting when you want to dig everything or old fields with few signals when you dig everything in hope of relics. It is the best for finding those really faint, deep signals. Of course, you can do this exact same thing with the smart screen totally blank and hunt in that mode. Now you can also adjust the iron mask screen to knock out various levels of iron. As you know, on the Explorer screens, iron mostly falls at the far left side of the screen and "goodies"- silver, copper, coins, some gold- are at the far right side. The murky middle holds lots of junk (tabs) but also most gold, some older deeper coins and other odd stuff. If the site you are hunting holds lots of iron junk such as nails, screws, indefinable iron lumps, these items can sound like coins especially if you hunt in the Conductive mode (as opposed to Ferrous mode) but that is a whole different topic. So you may want to discriminate out all or some of the iron. You can use your normal smart screen to do this, taking the small, medium, or large cursor to paint a black line up and down the far left side of the screen, a narrow one for small iron or a wider one (maybe 25% of the screen) to really knock out most iron (also knocking our some deep coins) This is time consuming, going click, click, click for several minutes. Or you can quickly do the same thing in the Iron Mask screen where you can do a band the whole height of the screen in one click and keep adding on bands as wide as you want. The iron mask screen is actually only the left HALF of the full smart screen in coverage, so if you blacken in the whole iron mask screen, it is identical to blackening in the left HALF of the smart screen. The iron mask screen has numbers- fully open, no blackened strips, it is "iron mask 16". Each strip you blacken in is one less number, so you can make it "15" or "14" and so on. Iron mask 14 is one used by many hunters as it knocks out a lot of iron without disturbing too many good things. So you can hunt in iron mask screen (make sure iron mask is "on" after setting and you will see a little area at bottom of screen where a black spot is on or off for iron mask). You are now detecting everything except most iron.
The SECOND main use for Iron Mask is the most helpful. You use it as a check for iffy signals. Some other detectors (such as some Fishers) have two separate discrimination channels that you can set to different levels, and then flick back and forth between them to see just how a signal varies, which can give you a much better idea of what it is. This is done with the Explorer by going back and forth between the Iron Mask screen, probably set to light iron discrimination (14 or 15) and your programmed smart screen. In time, you will begin to hunt more and more by the SOUND of a signal rather than its NUMBER or CURSOR POSITION on the screen- it is faster and many feel more accurate. Let's just say you have the factory COINS program on your smart screen and are hunting in that. You get a weak, deep iffy signal that doesn't ID well. You switch to Iron Mask screen and check the signal again- it will probably be much stronger, and when you learn the warbling sound given off by a deep good object, you can now hear the full tones and this helps ID the item. Bsed on that, you may decide it is a piece of iron or junk, or a possible coin. A deep coin gives off a variety of signals, some "textbook", some quite a ways off, and you will hear all these different sounds like you are quickly running your fingers over the holes in a flute while playing it. OR you can hunt in a light iron mask screen (if there aren't too many other junk items in the soil like pulltabs), and when you get a possible good signal, switch over to your programmed smart screen and check the signal again before digging. Deeper items will almost invariably have a much deeper, stronger signal when you remove most all discrimination (as in iron mask 14 or 15) as the entire "band" of variable signals given off by the object can now come through. The other advantage to hunting in an iron mask at this level is you will not have the threshhold sound "null" our when you pass over a rejected piece of iron. In junky ares, hunting in say "coins" program in smart screen, you may think your threshold has totally disappeared as you will never hear it while swinging the detector as it is constantly nulling out as you past over piece after piece of discriminated-out junk. Many feel that while the detector is in this brief "null" period it may not pick up a GOOD signal from a coin lying close to the junk you just passed over. However, if you are hunting wide-open or nearly so (iron mask 14 or 15) you will hear many more non-iron junk signals but since the sound does not null out when passing over them, the detector can quickly pick up that nearby coin so the tone jumps to the high coin signal. But in junky ground hunting the barrage of sounds will drive you crazy and for pure sanity force you into hunting in your smart screen with higher levels of discrimination knowing you may miss some good deep coins during those null periods. That is when you want to switch back to the iron mask screen to check the iffy signals you get. And of course there are those areas with little junk that you hunt in iron mask, and then encounter a sudden junky area so you switch to smart screen for a while.
I personally hunt in "ferrous" mode because in that mode all iron gives a deep low sound, and good metals- coins- a high sound. This is best for areas that have iron and coins but not many pull tabs. However, rusty bottle caps fall way over in the lower right corner of the screen and give a very coinlike sound in ferrous. In conductive mode, iron bottle caps give the low sound, but small iron like nails and coins both have high sounds. There is no perfect world. Tabs, nickels and most gold are sort of a middle tone in either mode. So pick your poison. If hunting in Ferrous (smart screen) blackening out the extreme lower right corner maybe about 1/4" both directions- will get rid of the bottle caps without knocking out too many good things. I often use a simple setup for moderately junky areas when hunting coins (not jewelry) and that is on smart screen make a big black "L", blackening out a band maybe 1/4 of the screen width down the far left side and same size across the bottom. This knocks out most all iron, bottle caps, and other undesirable junk. You will still get tabs, noticeable as a middle tone, but have enough clear area that coins, even older deeper ones with shifted signals, will come through. You may lose some things during nulls, but hunt slowly stopping any time you get a high signal and barely wiggling the detector, go over that spot East-West, then N-S, and if you get some high fairly repeatable tones rather equally in both directions it is probably good. You could switch over to the light (or blank) iron mask screen to recheck the signal and use that info to help make your decision. Then you may find the suspect signal is now bleating out heavy iron signals and pass it by (rusty iron often gives off occasional coin-type signals). Finally check the signal then in pinpoint and if you come up with the same spot that seemeed to also be the center of the signals in discrimination, dig it. If the center seems to jump a few inches it is probably a piece of iron, likely a nail. Be aware that in most areas as coins sink deeper and deeper that their signals start shifting away from coin and toward iron, so that very deep all-iron signals may in fact be coins. That is why you do not often get textbook number or sound readings on coins as you get to 6 or 8" deep or deeper, so don't go crazy air testing coins and only digging signals that give that exact number unless you are content with shallow, modern coins. Hope this helps.
