Teknetics Delta 4000 Review

With an 11-inch concentric searchcoil, this metal detector can scan for objects nearly a foot underground.

Our Verdict

The Teknetics Delta 4000 is an accurate metal detector that searches deep below the surface. It’s our top pick because it performed so well in our tests.

For

  • It picks up zinc really well.

Against

  • It holds the last reading too long, making it harder to pinpoint a buried object’s location.
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We spent about 21 hours in the lab testing metal detectors like the Teknetics Delta 4000.

We spent about 21 hours in the lab testing metal detectors like the Teknetics Delta 4000.
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The instructions included with metal detectors, like the booklet for the Teknetics Delta 4000, include a lot of useful information you should read before taking your detector out in the field.

The instructions included with metal detectors, like the booklet for the Teknetics Delta 4000, include a lot of useful information you should read before taking your detector out in the field.
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The Teknetics Delta 4000 is our best overall pick because it was the most accurate and easiest to use.

The Teknetics Delta 4000 is our best overall pick because it was the most accurate and easiest to use.
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The Teknetics Delta 4000 displays a target ID number corresponding with the type of metal it is detecting underground. Higher numbers, like this 82 reading, mean the object is likely a dime or a quarter.

The Teknetics Delta 4000 displays a target ID number corresponding with the type of metal it is detecting underground. Higher numbers, like this 82 reading, mean the object is likely a dime or a quarter.
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The Teknetics Delta 4000 runs on a 9-volt battery and users should get 20-25 hours of fun at a time.

The Teknetics Delta 4000 runs on a 9-volt battery and users should get 20-25 hours of fun at a time.
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The Teknetics Delta 4000 has a concentric searchcoil that can detect coin-sized objects up to 11 inches deep, though accuracy suffers with anything deeper than 8 inches.

The Teknetics Delta 4000 has a concentric searchcoil that can detect coin-sized objects up to 11 inches deep, though accuracy suffers with anything deeper than 8 inches.
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The Teknetics Delta 4000 weighs 2.3 pounds, which makes a difference after several hours of canvassing a field.

The Teknetics Delta 4000 weighs 2.3 pounds, which makes a difference after several hours of canvassing a field.
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The large screen on the Delta 4000 is easy to read in both sunny and cloudy weather.

The large screen on the Delta 4000 is easy to read in both sunny and cloudy weather.
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The Teknetics Delta 4000 has 10 sensitivity levels should you experience a lot of erratic beeping or nothing at all.

The Teknetics Delta 4000 has 10 sensitivity levels should you experience a lot of erratic beeping or nothing at all.
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In our tests, we buried objects at depths of 2, 6, 10 and 12 inches. The Teknetics Delta 4000 accurately identified 54 percent of the objects we buried and picked up 82 percent of the objects we buried regardless of whether the readout was accurate.

In our tests, we buried objects at depths of 2, 6, 10 and 12 inches. The Teknetics Delta 4000 accurately identified 54 percent of the objects we buried and picked up 82 percent of the objects we buried regardless of whether the readout was accurate.
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The Teknetics Delta got the depth reading right 32 percent of the time in our tests.

The Teknetics Delta got the depth reading right 32 percent of the time in our tests.
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The Teknetics Delta found 82 percent of the objects we buried.

The Teknetics Delta found 82 percent of the objects we buried.
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The Teknetics Delta displays an object’s target ID number, depth and type of metal on an LCD screen.

The Teknetics Delta displays an object’s target ID number, depth and type of metal on an LCD screen.
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The Teknetics Delta reset to its factory sensitivity level of 7 every time it was turned off and on again, causing it to beep erratically and loudly until the sensitivity level was lowered to 4.

The Teknetics Delta reset to its factory sensitivity level of 7 every time it was turned off and on again, causing it to beep erratically and loudly until the sensitivity level was lowered to 4.
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The Teknetics Delta worked best set at a sensitivity level of 4.

The Teknetics Delta worked best set at a sensitivity level of 4.

With an 11-inch concentric searchcoil, this metal detector can scan for objects nearly a foot underground. While you’re scanning, the screen shows you a target ID number corresponding to the type of metal you’ve found. A tab also lights up to give you an even better idea of what the treasure might be, differentiating between iron, a quarter, a silver dollar and so on. This way you won’t have to memorize as many target ID numbers. If you need a little help getting started, a handy chart is available in the instruction manual so you can see what target ID numbers correspond to which metal.

The Delta 4000 has eight levels of sensitivity ranging from 4 to 12. The factory setting was 8, and we found we didn’t have to change it to get readings on the various metals we buried. It automatically searches in discrimination mode, which excludes iron from your treasure hunt. You can customize this mode to eliminate more kinds of metal. You can also use the notching mode to selectively include or exclude a single type of metal. Pinpoint mode can give you an even better picture of what you might have found. This metal detector also has volume control so you can turn down the beeping if it’s getting on your nerves.

In our tests, the Delta 4000 picked up 82 percent of the objects we buried, the second-highest pickup rate of the detectors we tested. The Bounty Hunter Titanium Camo was the only device that found more objects. The Delta also correctly identified 54 percent of the objects we buried, one of the higher accuracy rates in our lineup. Disappointingly, it did not pick up most of the silver items we buried, though it did well with brass, zinc and aluminum.

This metal detector displays depth on a five-notch scale. One highlighted notch means the object is between the surface and 2 inches underground, and the more notches that light up, the deeper the object is, reaching 8 or more inches at five notches. The instruction manual says the 11-inch coil can search up to 11 inches deep but that accuracy diminishes once an object is buried 8 inches or deeper. In our tests, the Delta 4000 got an accurate depth reading 32 percent of the time, a mid-range accuracy rate compared to other models.

When the Delta 4000 discovers an object, we noticed the reading stays displayed on the screen for anywhere between five and 10 seconds. This was nice for our data gathering process, but it also means you need to sweep this detector very slowly. The reading stays on the screen while you continue to move, so you have to listen to the machine’s beeps to pinpoint an object’s exact location. This isn’t necessarily a bad thing but merely a unique quality that took time to adjust to.

This metal detector is easy to put together. You simply slide the pieces into place and they interlock. It runs on a 9-volt battery, giving you 20-25 hours of use before you have to replace it. This is standard among the metal detectors we tested. Teknetics also provides a five-year warranty, which is the longest in our comparison except for the Tesoro Mojave that has a lifetime warranty.

The Delta 4000 weighs 2.3 pounds and is one of the lighter machines in our lineup, so your arm won’t get tired quickly. Arm fatigue can be counteracted with an armrest strap that attaches to the detector and loops around your forearm. The Delta 4000 doesn’t come with one like the Garrett Ace 400 does, but the arm strap is available for purchase separately.