FIELD TEST

Metal Detector Field Test & Review - The Garrett AT Pro
By Andy Sabisch
From Page 32
October, 2011 issue of Lost Treasure

Garrett Electronics has been a leading producer of metal detection equipment for nearly 50 years and has strived to bring innovation and quality to the hobby.

I can attest to the performance of many Garrett detectors I have owned, starting with a BFO model my brother and I used in the late 1960’s and continuing through my current stable, which includes a Garrett Ace 250, 350, GTI 1500, Gold Stinger and an Infinium, as well as a pair of the Pro-Pointer pinpointer probes.

The ATPro is the latest addition to the Garrett hobby line and incorporated input from actual users to ensure features and functions were combined into a detector that could operate virtually anywhere, and provide features not found in a single package before.

Features

When the engineers at Garrett started on the ATPro project they had a tall order to fill. Not only did they need to develop circuitry that would provide capabilities not yet on the market, but they also planned to put the new electronics into a case that would be waterproof down to 10 feet.

In addition to the protection the new case design would also provide for land hunters caught off guard by the weather, Garrett recognized that a large segment of water hunters never ventured out past neck-deep water and did not need the added weight and cost of a case rated for 100’+.

With a long checklist of desired features and the direction to keep a cap on the price tag, the engineers went to work and the final product is certainly a homerun.

The ATPro clearly shares some of the lines found in the Ace family, including the S-rod handle, adjustable arm cuff, compact control housing that offers easy access to all of the adjustments and view of the LCD display, and the rugged yet lightweight Double-D search coil.

The ATPro is in essence two detectors in one. Recognizing that entry-level users wanted a detector that was simple to operate yet provided better than average performance, the engineers created a list of the features that would meet that goal with a minimum of adjustment required.

However, there were more seasoned hunters that demanded the adjustability to tackle sites that contained high mineralization, black sand, saltwater, ferrous trash and other challenges, as well as more information about detected targets.

In addition, as the entry-level users gained experience, they would also be looking for those capabilities and having a machine that provided upgrading without replacement.

With the touch of a single button on the ATPro, switching between the Standard and Pro modes provides both groups what they wanted!

The ATPro is controlled though the use of five touchpads (Mode/Power, Iron Audio, Pinpoint, Elimination and Ground Balance) and three rocker switches (Iron Discrimination, Sensitivity and Notch Discrimination).

While some controls provide multiple functions, they are well labeled, making them easy to understand and adjust even when the control housing is underwater. The LCD screen in the center of the control housing face provides details on the specific settings selected along with information on detected targets. Information displayed includes:

Target ID

A dual scale, each with 12 segments. The upper one indicates the probable ID of the detected target, while the lower one indicates what segments are being accepted or rejected based on the specific search mode selected.

A digital display in the center of the screen provides additional details to further identify targets using a 0-to-99 scale. The graphic above the LCD screen provides a quick reference as to where specific types of targets will typically register.

Target Depth

Displays the approximate target depth in 2” increments (2”, 4”, 6”, 8” or 10”+).

Iron Disc

A visual indication of the level of iron rejection selected (using a 0-to-40 scale).

Pinpoint

When the pinpoint mode is selected, the display changes and the upper target ID bar moves from left to right as the center of the coil approaches the center of the target to aid in zeroing in on the object.

Battery Condition

An icon showing the current battery strength from four bars (fully charged / new) to one bar (need to replace).

Search Mode

Indicates which search mode is selected (three in Standard and three in Pro mode).

Sensitivity

Depicts the current sensitivity level – eight possible levels are available.

Each of the search modes affords users with the ability to select what type of targets will be accepted or rejected based on the 12 individual notches shown on the LCD screen, as well as the new IRON DISCRIMINATION range that has been added to the ATPro.

The IRON DISCRIMINATION circuit allows one to define how much iron will be rejected and is extremely useful when searching sites that may be littered with small pieces of iron yet contain larger iron artifacts that may be desirable.

Previously, rejecting iron would cause items to be missed if smaller iron was rejected.

The ATPro allows users to select just how much iron to reject ranging from 0 to 40 based on what they are finding. The three modes identified on the screen are CUSTOM, COINS and ZERO, and all can be adjusted to meet specific needs based on the types of targets. Any changes made in the CUSTOM mode are retained even when the detector is turned off.

The design team recognized that electrical interference from power lines, transmitters, or nearby detectors could cause erratic operation, so a frequency-shift option was incorporated into the ATPro. If you notice the detector chattering unexpectedly, one of the four frequency settings will likely solve the problem.

Another unique feature on the ATPro is its audio capability. It has a built-in speaker, which can be used for all forms of treasure hunting, as well as a headphone connection where either the land set that comes with the detector or the optional waterproof set can be connected.

Surprisingly, the built-in speaker has been designed to withstand submergence to 10’ yet is easily heard when searching above water. Speaking of audio capabilities, in addition to the visual target ID information, the ATPro also provides tone target ID where targets are classified into three different “bins,” with each producing a unique audio response.

After a little time in the field, one can quickly determine what targets are worth investigating based on their audio response and then glance at the LCD screen to get a more precise identification.

The major difference between the Standard and Pro modes is how the detector responds audibly to detected targets. In the Standard mode, a target that is accepted will produce an audio response, which will be the same volume regardless of the size and / or depth of the target…best described as a “basic beep,” although the three different audio tones will still be available.

In the Pro mode, the audio response will vary based on the depth and size of the target; i.e., smaller / deeper targets will produce fainter signals, which allows users to gleam additional information about a target before attempting to recover it. In addition, the ATPro will recover quicker after passing over a target when in the Pro mode, allowing targets close together to be separated and identified.

Proper ground balancing has been long recognized as being essential to obtaining the maximum detection depth possible, yet is the one adjustment most “feared” by detectorists since an improper setting can actually cost you performance, especially as ground mineralization increases.

The ATPro provides for both automatic and manual ground balance adjustment that ensures optimal performance is obtained under challenging conditions and does so with simple and intuitive controls.

The non-motion pinpoint circuit is accessible in any search mode and allows one to quickly center the coil over detected targets with the combination of the audio response, graphical aid, and real-time depth indication.

The ATPro differs from other models in the Garrett line, with the exception of the Gold Stinger, by operating a 15kHz, which was chosen to provide enhanced detection of smaller targets as well increased sensitivity to low-to-medium conductivity targets, making it an excellent choice for beach and relic hunters.

The ATPro is powered by four AA batteries, which will provide between 20 to 40 hours of use. Rechargeable batteries – either NiMH or Lion - can be used with no loss of performance, although they tend to provide slightly less operating time. Keeping an eye on the Battery Strength indicator will ensure you are not forced to cut your hunt short.

The ATPro, with batteries and the stock 8.5”x11” Double-D coil, weighs in at just a tad over 3 pounds. Its overall balance and padded handgrip allow it to be used for hours…even in neck-deep water!

Field Test

After some bench testing and a quick pass through my test garden to familiarize myself with the ATPro’s features and response to specific targets, I opted to head to a wooded site that held several foundations dating back to the 1800’s due to the summer heat we were experiencing, as the shade would offer some relief.

Using the Automatic Ground Balance option quickly set the ATPro for the ground conditions present and a reading of “68” indicated the area was moderately mineralized. I selected the ZERO search mode in order to get a feel for how much metal was present and what it consisted of.

As expected, the area near the foundations had a great deal of small iron and, after recovering a handful of nails, pieces of barbed wire, and fragments of the old metal roofs, I increased the IRON DISC to “25” and kept the IRON AUDIO off to reduce the signals from unwanted ferrous targets.

The usefulness of the ability to select the amount of iron rejection was readily apparent as several larger iron relics, such as horse and mule shoes, an axe head, and a large, hand-wrought spike were unearthed, yet the smaller ferrous trash that littered the area was rejected or readily identifiable based on the broken audio response it produced.

While I tend to use headphones virtually all the time to ensure I do not miss signals, I tried the ATPro without them to gauge the volume produced by the internal speaker and was satisfied at how loud signals were from a fully submersible speaker.

While I have come to appreciate the simplicity of the notch target ID system found on other Garrett detectors, I found that having the additional information in the form of the digital numerical values allowed me to identify targets with a degree of accuracy not possible with the notch system alone.

One area contained a number of shotgun shell casings. After checking a few and seeing what number they produced, I was able to ignore others yet still locate and recover two brass buttons that produced the same notch indication, but a different digital value.

Even with the shade and a mild breeze, a few hours was all I could muster. Even in that short period of time keepers had been found, including Indian Head pennies, a wick assembly from an oil lamp, an ornate brass hinge, a silver plated fork, a thimble with the letters “EHM” engraved on the inside, and the aforementioned buttons.

The enhanced iron identification capabilities were evident in searching the site based on the lack of small iron trash, yet several larger ferrous relics went in my pouch.

While one of the smaller coils may have been a better choice in the areas surrounding the foundations, due to the concentration of targets, searching in the Pro mode with the appropriate level of discrimination selected and a slower sweep speed allowed the ATPro to detect good targets from amongst ferrous trash quite easily.

The ability to submerge the ATPro was appreciated when I took it to an informal swimming area on a nearby lake.

Opting for the CUSTOM discrimination pattern in the Pro search mode, I rejected the entire ferrous range and the first notch above that point and accepted everything else. Since gold jewelry can register in a wide range, too much discrimination will almost certainly ensure you will miss what could be the find of the day.

Ground balancing the ATPro in ankle-deep water, I proceeded to wade out, being careful to not lose my balance or step in a hole and dunk the land headphones.

If you plan on doing much water hunting, investing in a pair of underwater headphones is highly recommended and, at under $100, they are worth the price even for land hunting in bad weather.

I was somewhat anxious when the control housing slipped beneath the surface as I continued searching away from shore, and I lifted it up more than once to prove that the LCD remained watertight…and it did.

Coins were fairly plentiful, although they were all recent drops, and it quickly became evident that beverages with pull-tabs and screw caps were consumed in large quantities by those frequenting the area.

However, the audio target ID system allowed me to get a good idea as to what had been detected and, by raising the housing enough to read the digital display, I gained additional information to identify targets.

One of the last targets I found before packing it in gave a solid signal that registered as a pull-tab on the notch ID scale, yet the “51” digital value was lower than where other tabs had been. As the sand filtered from my scoop, I saw the glint of gold and picked up a 14KT man’s pinky ring with a small diamond…great way to end the day!

Overall, the ATPro handled the shallow water with ease and offered target ID information – both audibly and visually – that one does not expect from a fully submersible detector.

Having been a long-time water hunter that started in the early 1970’s, I found that the ATPro was a detector that offered an above average level of performance and ease of operation in the water that will likely allow many treasure hunters, that might be limited to a single detector, to experience the excitement water hunting can bring when jewelry is recovered.

Fellow Lost Treasure author Chris Gholson tested the ATPro in the goldfields of Arizona and his field test is well worth reviewing if you are interested in using it for electronic prospecting – it is available at www.losttreasure.com

Due to the time constraints associated with getting this report completed, I was not able to test the ATPro out in as many sites as I had hoped, but the online version will contain additional results from both land and water locations.

Summary

The new ATPro was intended to meet the needs and demands of a wide range of treasure hunters and the engineers at Garrett met that challenge on all fronts.

The ATPro’s all-terrain design includes features not found on many land-only models at a weight that allows for all-day use and at a price within almost anyone’s budget.

The Standard modes are ideally suited for newcomers that want performance with minimal adjustments, while the Pro modes provide additional information and capabilities for those demanding more.

Waterproof, lightweight and affordable, with features never before seen on a detector that excels under such a wide range of conditions, it’s easy to see why the ATPro has become so popular with hunters around the world.

The AT Pro lists for $699.95 and comes with a 2-year factory warranty. Optional search coils are available.

For more information or to request a catalog, contact the factory at (972) 494-6151, 1881 West State Street, Garland, TX 75042, or check out their website with online training videos for the ATPro at http://www.garrett.com

Be sure to mention you read about the new ATPro in Lost Treasure.

Copyright © 1996-2017 LostTreasure®, Inc. All Rights Reserved.