Pinpointing Targets - The million-mile stare

 One of the most difficult skills to master in metal detecting is accurately targeting signals under the coil. Some of this is due more to the lousy targeting abilities of less costly detectors, than the operator, Now, with small, handheld pulse detectors, many just assume digging a 12" wide, pizza-sized hole will suffice. Then waving the small electronic magic wand over the area, it will quickly and easily locate the target. We quickly remove and marvel at the gold coin we just pinpointed, then head for home. It's Miller time! No, sorry, just no. 

Pinpointing a target with a VLF metal detector is dependent on two things, well really one thing, the search coil, but in two flavors; concentric or the wide-scan (also known as a double-D) coil. When you find a likely target you would like to dig, with a concentric coil, you swing the coil back and forth above the target until the signal is either the loudest or the highest tone, or both, the detected target location will usually be, visually, at the center of the concentric coil. Usually I look for an item at the target point under the coil...a leaf, a small stone, twig...and stare at it as you swing the coil away ("The Million-Mile Stare") and you prepare to dig. When I first started out detecting, my technique after locating the target center in the concentric coil, I would do "the-million-mile-stare" at that location, swing the coil away, and push a coin-probe in the target center. It worked well as a visual-aid when digging, until I got the technique down pat. 

concentric target center on the left is usually where the red x is indicated
wide-scan (double-d) target center in green X is punching the "pinpoint control
Wide-scan (double-d) target locations red X front and back using "wiggle" method

You will find more expensive detectors will come with a wide-scan or "double-d" coil that pinpoints somewhat differently, When I switched from a concentric coil to a wide-scan coil, I found it somewhat difficult to pinpoint very well with the double-d, and had a few choice words with the %$#!&%$!& thing while out hunting the beach!  Metal detector manufacturers, thanks to computerization, have electronically "forced" the circuits to simulate a pinpointed target physically at the center of the double-d coil. And there is nothing wrong with this, as machines using the double-d coil get more technically advanced, pinpointing gets more accurate. BUT, and its a big BUT, understanding and using this coil to best advantage means using it as it was designed. I don't want to launch into another explanation on coils and how they work, just how they pin-point.

The solid strip down the center of the coil is called "the hot-shoe" on a double-d. When you are pinpointing a target, you don't have to use (although you can) the "pinpoint" button, but use a technique called the "wiggle" method. Upon gaining a target, in any mode you choose, you narrowly wiggle the coil back and forth while moving forward slowly, maintaining the target signal. When the target signal suddenly drops off, the target is directly behind the back edge of the coil. And this ability is what make water hunting possible with this type coil. Hunting in chest-deep muddy water? Can't see the coil? Use this technique, and once target is pinpointed, put your toe touching the back of the coil, swing the coil away, then move your toe back a few inches, put the long-handled beach scoop at a 45 degree angle just in front of your toe and dig, Chances are good you will dig the target on the first try, and you never even saw the bottom, you did it all by practice and feel. Don't try this with a concentric coil, though.

Another method in detector pinpointing techniques, using either type coil, is called "de-tuning," which increases the physical accuracy of the coil. As you swing over the target, as soon as you swing slightly away from the target center, punch the pinpoint button off and then punch it back on, and keep swinging, narrowing your sweep each time you de-tune. It takes some practice, but you will be making surgical recoveries of targets as your skills improve.

Still another technique we used back in the day, before electronic hand-held pinpointing devices were available, and still useful today if you cannot yet afford a pin-pointer, we called poor man's pinpointing. The fact was we were not poor, we were just underequipped. You managed to isolate the target using the detector's pinpointing feature, but the target is small, and hard to see or feel in dirt of the hole you dug, especially if you were wearing gloves. Frustrating though it is, the fact that a search coil, no matter what the type, will detect on both sides of the coil saves the day! Grab a handful of dirt from the dig and wave it over the top of your search coil until one handful sounds off, then poke carefully through the dirt in your palm until the target is located. It's Miller Time!

The really important aspect of all this, to you, and the hobby in general, is to master pinpointing, so you can excavate detected targets with surgical precision, and leave the 12" wide digs to the prairie dogs, keeping our hobby safe for coming generations.