Fisher Cz-6 Quicksilver

By Reginald G. Sniff
From page 36 of the March, 1992 issue of Lost Treasure
Copyright © 1992 Lost Treasure, Inc. all rights reserved

One of the new detectors in the limelight is Fisher Research Laboratory's new target ID detector, the CZ-6 QuickSilver. Simply stated, this new detector packs a lot of new features into a sleek black case, providing exceptional depth capabilities.

The new CZ-6 QuickSilver can be best described as a sophisticated yet simple-to-operate ultra deepseeking target ID machine. Instead of a fancy digital readout or a meter with a large array of different probable targets, Fisher has opted to develop a meter display that is divided into seven distinct categories.

Lacking numbers such as 0 to 100, this meter display is not only unique but definitely distinct since it places nickels next to the more conductive coins such as zinc pennies and other coins. Listed from left to right, the categories are iron, pull tabs, foil, footprint tabs, nickel, zinc pennies, and coins.

Located at the top of the meter are two bands (one gold and the other silver) which indicate the areas where most targets of such nature will fall. At the bottom of the meter is a depth indication and battery check.

Complimenting the visual target ID feature is a three-tone audio ID system. The three tones designating three distinct types of targets are: a low tone for iron and other targets too deep to be analyzed accurately, a medium tone for targets that are typically trash items such as bottle caps, pull tabs, foil, etc., and a high tone for all coins including nickels. One other audio ID feature found on the CZ-6 QuickSilver is a distinct "bell" tone indicating a signal overload. Ah overload normally occurs if a target is large such as a sprinkler head or is highly responsive like an aluminum bottle cap.

For adjustments, the new CZ-6 QuickSilver has 4 adjustable controls, one two-position switch marked normal/salt water, and a large convenient push button for pinpointing depth reading the target.

The four adjustable controls are: a single turn ground-balance control, an op/off/volume control, a battery check/sensitivity control, and an eight-position auto-tune/discrimination level control.

Because this detector is new from the ground up, the CZ-6 QuickSilver utilizes a different coil than Fisher's other detectors. The standard coil is anew 8-inch coil in what is called the open center "spider" design. The only optional coil available at this time is a 10-1, 2 inch design.

One item missing as standard equipment is a speaker. Because some people prefer to use a speaker, Fisher offers an optional one that's designed to snap on to the top of the control housing. This lack of a speaker made it possible to design the control housing free of any obvious openings. As a result, the CZ-6 QuickSilver is designated as splash and rain resistant. To further insure the integrity of the sealing of the unit, the toggle switch is equipped with a rubber boot cover. Although the unit is not designed to be submerged, it can take rainstorms and other weather problems without fear of negative effects.

The CZ-6 QuickSilver contains one very innovative feature that can't be seen. Unlike most detectors which transmit one frequency to detect targets, this new detector transmits two. Analysis of a target and the ground mineralization are done by combining the signals from the different frequencies and analyzing the target. Fisher calls this technique their Fourier Domain Analysis. This terminology is the technical name for an electronic analysis of a signal by evaluating the different frequencies that make up the signal.


Although I had heard of the new CZ-6 QuickSilver, I didn't see one until I went to Treasure Week in Seymour, Indiana. Unfortunately, I arrived after Fisher's designated day and, as a result, I didn't see a formal demonstration of the unit. However, Fisher was well represented the rest of the week by Rich Green of PRT Electronics who was nice enough to let me try one of the CZ-6 QuickSilver's for a few minutes. Although I didn't get to give the detector an extensive test, I knew after a few minutes with the CZ-6 QuickSilver that Fisher had introduced a very impressive and sensitive detector.


When the CZ-6 QuickSilver sent for field testing arrived I was surprised. Not only did they send the detector, but Fisher was nice enough to include the optional speaker, a set of earphones, and the optional carrying case. After using this combination I can safely say that it's an ideal system since it provides all items necessary for all types of use as well as providing a safe means for transporting the unit.

Although I was anxious to see how it performed in the Colorado soil, I took time to read the owner's manual thoroughly. Like their detector, it was obvious that Fisher went to great lengths to provide a quality owner's manual. This booklet tells a new operator how to get started quickly, and gives a brief but thorough description of all the controls and how to properly adjust them. Also included in the manual are a couple of quick and unique tricks that make the owner's manual well worth reading.

After finishing the manual I took the CZ-6 QuickSilver out for a test run in my front yard. The first thing I did was to try the two different techniques mentioned in the owner's manual for ground-balancing the instrument. I began by selecting the normal mode of the two-position switch marked normal/salt water. Although the mineralization is extremely severe, both ground adjustment techniques were flawless in their adjustment.

The first technique consisted of raising the searchcoil about a foot from the ground, pushing the pinpoint pushbutton and, while holding the pushbutton in, lowering the coil to the ground and adjusting the ground-balance control clockwise until an audio signal was heard. Then I backed the ground-balance control off counterclockwise until the tone just disappeared. At this point the unit was ground balanced.

The second technique is a common technique used on other detectors. First I selected the first position on the discrimination control, marked auto-tune (which is a rapid auto-tune all-metals mode). Next, I raised and lowered the searchcoil towards the ground while adjusting the ground balance control for minimum signal variation when the coil was raised or lowered. When little or no change is heard as the searchcoil is raised and lowered, the detector is ground balanced.

Once I was satisfied with the ground adjustment, I set up the rest of the detector. I began with a setting of 5 for both the sensitivity and the audio level control. The discrimination control was set at the on position marked 1 which just rejects iron objects.

To begin my test on the various targets l buried in my yard; I selected a 6-1/2 inch deep dime as my first target. The CZ-6 QuickSilver responded with a loud solid signal. A quick check with the pinpoint mode displayed the depth of a little over six inches. Surprised that this target was so easily detected, I began to reduce the sensitivity setting and found I could still detect the dime with a sensitivity control just above 2. At a setting of just a little less than 2, I could still detect the dime with careful sweep techniques. Needless to say, I was very impressed with the CZ-6 QuickSilver's response. In the past I have found that most detectors have to be at almost maximum sensitivity to detect this coin.

All other targets responded with crisp, repeatable signals until I got to a penny that was buried at a depth of about five inches. On this target, the CZ-6 Quicksilver responded with an intermittent positive signal. Somewhat surprised at this, I immediately tested the same target with six other well-known detectors. Only one of the other detectors would respond intermittently. The rest wouldn't respond at all in the discrimination mode. None responded with the consistency of the CZ-6 Quicksilver.

What I determined and have suspected for a long time was pennies and other copper objects respond strangely during the hot, dry periods when the soil is very dry.

The problem of not being able to consistently detect this coin was not the fault of the CZ-6 QuickSilver, but was caused by negative effects of the soil during dry periods. The CZ-6 Quicksilver had, in fact, done a better job than any of the other detectors.

One of the unique features of this detector is the unique response when the detector senses a large or highly responsive signal. Referred to as a "bell" tone, this distinct signal is easily recognized. To substantiate its effectiveness, I tested several large targets such as can lids, aluminum cans, and screw caps. All responded with the overload response.

Next, I tried the larger coins that may be found such as quarters, halves, and silver dollars. None of these targets would respond with the overload response unless the searchcoil was within an inch or less from the coins.

Since I normally search with the coil a couple of inches from the ground, I felt safe in assuming any overload signal was coming from trash, especially in trashy areas such as parks. In other areas, I decided that I would check the target's size and shape whenever possible, using the all-metal mode before dismissing the target as junk.

During my initial testing, I carefully checked the depth-indicating feature on various targets. Like the other features of this new detector, I found the accuracy of depth feature to be impressive. In fact, I felt it to be as accurate and in most cases more accurate than others I have tested. More importantly, regardless of the setting of the sensitivity control, the depth indication remained constant.

Impressed with the exceptional sensitivity in both the pinpoint and discriminate mode to coin-size objects, I felt sure that this instrument would also work exceptionally well for relic hunting as well as coin hunting. To round out the test, I decided to see how this new detector responded to gold nuggets.

I selected a fairly thin one (a little smaller in diameter than a pencil eraser) as my test target. The CZ-6 Quicksilver responded with a loud response in all modes. However, in the discrimination mode, the detector analyzed the target as a piece of iron most of the time.

Next I selected a couple of nuggets (about 3/4-ounce total) to use as a test target. This time I got a medium tone and a footprint tab reading. Knowing that gold nuggets respond at the lower end of the conductivity scale neither of the nugget tests surprised me.

From these two tests, I determined that if I were to use this detector as a nugget detector, I would either run in auto-tune or at the 0 position of the discrimination control. Furthermore, I would dig all targets that responded as iron, especially if the target was small or deep.

By the time I finished my initial testing, I determined that this detector was extremely sensitive. As a result, I decided to start out with the sensitivity control set at no more than 5 (about 50% of the total adjustment). At this setting, the detector seemed to have more sensitivity than most and yet was extremely quiet.


Since parks are a popular place to use target ID detectors, I decided to see how the CZ-6 Quicksilver would perform. The first park is one located a few blocks from my house. For fun, I initially set the discrimination level on the 0 setting. I set both the sensitivity and volume controls at 5.

With the 0 discrimination setting I could hear all targets including the iron objects. At this setting it's easy to see why a detector might respond with an occasional false signal. The amount of trash that accumulates in a park over three/fourths of a century is phenomenal.

After a brief time, I changed the discrimination setting to reject iron objects and just concentrated on nonferrous targets. During this phase of the testing I found the target ID to be extremely accurate. In fact, I felt that it was one of the most accurate that I have used. With the exception of the severely bent or broken pull tabs, almost all trash seemed to fall in its perspective slots as indicated on the meter.

Although I found the CZ-6 QuickSilver to be an extremely quiet detector, it would (like other detectors) respond with an occasional intermittent positive high frequency response over trash. This normally occurred when several pieces of trash were close to one another.

One common trash item found in the park, the ever present aluminum screwcap, was very easily differentiated from a zinc penny. In almost all cases, the cap would respond with an overload signal, especially if the target was checked in the all-metal mode. As a result, after digging several screwcaps for verification, I dismissed most of the targets responding with an overload response as junk items.

Since nickels have always been a problem to distinguish from other trash, I decided to keep track of and dig all targets that fell in that range. At the end of the first outing, I had detected eight targets that responded consistently with a nickel response. Of those, five were nickels, one was the tab portion of a pull tab, and the other two were badly deformed pull tabs. I felt this was as accurate as any detector can get under these circumstances.

Although I had deeper positive indications, the deepest good target dug was a Wheatback at a little over five inches. Since the soil was relatively dry in many areas, I felt it best to wait until another time to dig the really deep ones.

Several days later, I visited another park. At this location, I was fortunate to find areas where the ground was really soaked, making it safe to dig some of the deeper targets. One of the first targets encountered was a nice sharp response indicating a depth of a little over six inches.

Checking the target in the pinpoint mode, I knew that I had found a silver dime. Somehow the smaller size and the silver content make the target sound a little sharper than the typical pinpoint response from copper objects. After digging a little over 5 inches, I saw the 1917 Mercury dime imbedded in the dirt.

What made this target seem impressive was the fact that it was at an angle and not flat. A little later, I received another solid positive coin response that pinpointed to a depth of about seven inches. This target turned out to be a rather blah token about a nickel-size that said good for 5 cents in trade on one side and the letter K on the other. This target turned out to be somewhere between eight and nine inches in depth.

The last target dug I considered of significance was nothing but a piece of lead approximately one-by-two inches in size. Fortunately, this target was located in a bare area of the park where grass hasn't grown for years.

If it wasn't in such an area, I wouldn't have known what it was since it turned out to be over a foot deep. I was very impressed with the depth capabilities of this instrument.

While digging several of the "iffy" targets, I found that the CZ-6 QuickSilver will respond with intermittent good responses to certain trash objects like the owner's manual states. The more common culprits are rusty nails buried in the ground at an angle. For some reason, a positive signal will occur off to the side of the end pointing upwards.

I found that I could quickly check the immediate area for a wide or double-blip response in the all-metal mode to determine these nails. Also, the good response would almost always occur when the searchcoil was in a certain orientation over the nail. Moving around the target 90 degrees and sweeping again would cause the target to be ignored in most cases.

By the time I checked out a third park, I was glad that Fisher had sent the earphones. To get the maximum benefit of the CZ-6 Quicksilver, one needs a good set of earphones equipped with volume controls. The reason is because an additional feature of the CZ-6 QuickSilver associated with the volume control is something called audio boost.

When the volume control is advanced beyond the halfway point, all weaker signals are greatly amplified while the louder signals remain the same level. Therefore, earphones with adjustable controls are needed to set the maximum audio level and the detector's volume control can be advanced to increase the signal level of the weakest signals.

At a third park, I began to play with all the controls. First I advanced both the sensitivity and the volume controls to maximum. At these settings, even the deepest targets responded with loud solid signals in both the discrimination and pinpoint modes. Since all signals seemed so much larger and louder, the only way I could really tell any relative depth was to observe the depth indication.

With the controls near maximum, the detector was obviously more sensitive and, as a result, there was a higher incidence of intermittent positive indications. After a short time I decided to run the detector with about 50% sensitivity; this seemed to give about the same depth without many of the false signals.


Another good test of a detector is how it responds in the trashy environment of a ghost town. For the CZ-6 Quicksilver, this type of area was easy. For example, common pieces of trash found at such locations are large rusty pieces of tin cans; these were easily recognizable because they responded with the familiar overload indication, surprisingly, most of the smaller pieces of rusty metal were totally ignored.

About the only pieces of rusty junk that would give intermittent or solid responses were certain small can lids and some flat rusty washers or other rusty trash that were circular in shape.

At the first site, I didn't find anything significant, partly because the area had recently been thoroughly searched by a treasure hunting club and also because the ground was extremely dry. I did find one unique item, a fancy rouge container, recovered from about five inches. My granddaughter, who is my digging assistant on such outings, quickly claimed this prize as hers. Unfortunately, before the day was over, she managed to lose it again.

By the end of the day, I had retrieved a couple of handfuls of items made of brass and copper, along with other pieces of non-ferrous items, but no coins. During this time I found it best not to look at the target ID indications, rather relying on the audio ID system to evaluate the targets.

The reason I did this was most of the items indicated such as pull tabs, foil, and footprint tabs are scarce in such locations. In fact, I feel that in areas such as ghost towns, old yards, and certain other locations, it's best to dig all targets that are non-ferrous in nature regardless of their visual response.


Fisher detectors have long been known for their quality in workmanship and extraordinary depth capabilities the CZ-6 Quicksilver I tested is a perfect example of such features.

Unfortunately, there wasn't room for a field test and still mention in detail all the other features of the CZ-6 Quicksilver such as the nonmetallic lower stem, the three piece positive locking S rod, the built-in convenient hip-mounting arrangement, the built-in detector stand, and the other operating features such as the Fisher and the well-known VCO response in the pinpoint mode. Also, salt water is a little scarce around Colorado, so I didn't get the opportunity to try the salt water mode.

During my testing l really couldn't find any serious flaws with this instrument. However, I feel that new owners should remember that many unique items and most of the more valuable gold items fall in the meter ranges marked by typical trash targets found in parks. So when searching beaches, ghost towns, old yards, and other out of the way areas, it would be best to ignore the target ID indications and dig all non-ferrous objects.

Overall, I found this detector to have extraordinary depth capabilities coupled with an impressively accurate target and audio ID system. Simply stated, if you're looking for a professional, full-featured deepseeking detector, I heartily recommend that you try this new detector for yourself. I think that you'll be amazed.

To better appreciate this instrument, I recommend that you contact Fisher Research Laboratory by calling (209) 826-3292 for more information, or visit your nearby Fisher dealer for a thorough demonstration.