Fisher M-Scope CZ-20 QuickSilver User manual

CZ-20 Quicksilver
Operating Manual
Deep Search, Body Mount, Target I.D. Metal Detector
FISHER RESEARCH LABORATORY

CONTENTS
About Your CZ-20 ....................................................................pg. 1
Condensed Operating Instructions .......................................pg. 3
Assembly ..................................................................................pg. 5
Setting Up..................................................................................pg. 6
For Land or Shallow Water .....................................................pg. 6
For Diving..................................................................................pg. 7
For Hipmounting ......................................................................pg. 8
Control Panel ...........................................................................pg. 9
Turn on Procedure ..................................................................pg. 10
Ground Balancing..................................................................pg. 10
Pushbutton ...............................................................................pg. 11
Bobbing ...................................................................................pg. 12
Search Modes.........................................................................pg. 14
Auto Tune.................................................................................pg. 14
Target-I.D. ................................................................................pg. 15
Chart ........................................................................................pg. 17
Searching on Land or in Shallow Water ..............................pg. 17
Searching Underwater ..........................................................pg. 19
Pinpointing...............................................................................pg. 20
Target Identification ............................................................... pg. 21
Target Recovery .....................................................................pg. 23
Recovery Tools .......................................................................pg. 24
False Signals ............................................................................ pg. 25
Operating Tips.........................................................................pg. 28
Battery Replacement.............................................................pg. 30
Maintenance ..........................................................................pg. 32
Five Ways to Preserve Treasure Hunting ..............................pg. 32
Treasure Hunters Code of Ethics ...........................................pg. 34
Where To Use Your Metal Detector In the U.S. ....................pg. 35
Specifications .........................................................................pg. 36
Accessories............................................................................. pg. 38
Service.....................................................................................pg. 39

1
ABOUT YOUR DETECTOR
Your CZ-20 QuickSilver is truly an all-purpose metal detector
engineered for land, beach, salt and fresh-water treasure
hunters. Here are some important built-in features:
1. Leakproof: Submersible to 250 feet, headphones
and all.
2. 3-Tone Target I.D.: A low tone for iron; a mid-tone
for pull tabs, foil and most gold rings; and a high
tone for U.S. coins, silver rings and some gold rings.
3.Visual Target Response: Two bright,red LED’s flash
over targets, varying in intensity according to
target signal strength.
4. Depth: Patented Fourier domain signal analysis.
Two deep-seeking, ground-compensating VLF
signals (one at 5 KHz and one at 15 KHz) provide
twice as much target information for accurate
analysis and identification.
5. Two Search Modes: A silent-running, slow-motion
target-I.D. mode and a hot, wide-scan autotune
mode for all-metal searching.
6. VCO No-Motion Pinpointing: Just push the
pinpoint button and the signal tone increases in
pitch and volume as the center of the coil
approaches the target.
7. Big-Target Alert: Ordinary detector circuits
overload on large, shallow targets, identifying them
as good targets. But not the CZ-20. A distinctive bell
tone immediately warns you that the target is too
large to identify.
8. Faint-Target Audio Boost: The lower range of the
volume control is like any other that you’ve used.
But as you increase it above mid-range, strong
target sounds remain at a fixed volume while faint,
deep-target sounds continue to get louder.
9. Pushbutton Ground Balance: Just push the
pinpoint button and lower the coil to the ground.
Then set the ground control just below the audio
tone and you are precisely tuned for on-site

ABOUT YOUR DETECTOR
2
conditions.
10. Separately Sealed Battery Compartment:
Protects the electronics from accidental flooding.
11. Spider Coils: Your choice of the all-purpose 8-
inch or deep-seeking 10 1/2-inch Spider coils. Light,
tough and with open centers for accurate
pinpointing. The hot, little 5-inch coil is great for
extremely trashy areas, tight spots or highly
mineralized ground.
12. Balanced, Comfortable and Hipmountable:
Cushioned arm rest, soft foam grip and a control
housing that slips off the handle and onto your belt.
13. Easy to Use: Just pick it up, set the control on
the red circles and start searching in a “coins-only”
mode. Or for maximum performance, you can
easily adjust the controls for your own specific
situation.
Read this instruction manual thoroughly, practice often and
you’re in for some exciting treasure hunting. Drop us a line if you
have any questions, comments or good finds to tell us about. In
the meantime . . .
Good Hunting,
Fisher Research Laboratory

3
CONDENSED OPERATING INSTRUCTIONS
Factory Pre-Set ‘Turn-On-and-Go’ Marks
Your CZ-20 QuickSilver is fairly simple to operate, especially
when compared to other target-I.D. machines. Even so, we
strongly recommend that your read this entire manual. You’ll
be able to tune your CZ-20 to your specific needs and
conditions. And if you have a good understanding of how to
do it and why, you’ll find more.
But if you just can’t wait any longer, and you’re an
experienced detector user, here’s some quick instructions to
get you going.
Factory pre-
set turn-on-
and-go
marks
(circled in
red on your
CZ-20 control
panel) can
get you up
and running
with your CZ-
20
immediately.
1. Set all the controls to the red “Turn-On-and-Go”
marks:
GROUND = 5
DISC = 4
SENSITIVITY = 3
VOLUME = 5
This puts you in a “coins-only” mode, and you’re
ready to start searching. Keep in mind that the
Pre-set
Audio
Boost
mark at
“5”
Pre-set
SENSITIVITY
mark at “3”
Pre-set
DISCRIMINATION
mark at “4”
Pre-set
GROUND
mark at “5”

4
GROUND setting of “5” is probably not the
optimum setting for the ground you’re searching,
and that’s why the sensitivity level is lowto
reduce false signals caused by ground
mineralization.
2. Adjust the volume control for a comfortable
volume when the coil is passed over a large,
shallow target.
3. Travel slowly, overlap your sweeps and keep
the search coil moving. Remember, you’re in a
“motion” search mode, and the coil must be
moving at least slightly to detect a target.
4. When you get a good, repeatable signal,
pinpoint the target by placing the coil on the
ground away from the target, pushing and
holding the pinpoint button and then bringing the
coil back over the target.
5. Good hunting!
CONDENSED OPERATING INSTRUCTIONS

5
ASSEMBLY
1. Remove the headphone, handle and search-
coil assemblies from the carrying case. Be careful
not to damage the foam-rubber inserts or put any
strain on the cable connections.
2. Adjust the lower stem to the approximate length
you will be using: extended for stand-up use or as
short as possible for diving. To extend the lower
stem, push in the spring lock, pull out the lower stem
and let the spring lock snap into another hole.
3. Unwind just enough cable to attach the search
coil to the lower stem.
4. Remove the bolt and wing nut from the search
coil. Line up the hole in the lower stem between
the two holes in the search coil “ears.” Attach the
coil to the stem with the bolt and wing nut and
finger tighten.
5. The arm rest may be repositioned for maximum
comfort by removing the arm-rest screws, sliding
the arm rest to the next screw hole and re-installing
the arm-rest screws.
Your Fisher CZ-20 QuickSilver is built to last for years.
Submersible
Adjustable arm rest
Control Housing
Control Panel
Target I.D.
Foam hand
7-foot Search Coil
Fiberglass upper
Arm-rest
Battery access 8-inch Spider
Nylon Wing nut
Fiberglass
reinforced
nylon lower
Headphone

6
SETTING UP FOR LAND OR SHALLOW WATER
Put the headphones around your neck to keep them out of the
way while making the following adjustments:
SETTING UP
ASSEMBLY
However, it’s a sophisticated electronic instrument
containing state-of-the-art components. Handle it
carefully, care for it regularly, and it will give you
years of dependable service. The CZ-20 requires
little assembly. Unpack it carefully and save the
carton; it comes in handy if you ever have to return
the instrument for service.
When searching on land
or in shallow water, keep
your arm straight and your
search coil no more than
2 inches above the
ground.
Adjustable Arm Rest
Scews
Screw Hole
Upper Stem

7
Control housing (Never hipmount your
control housing while diving.)
Shortened Stem length
Extra, coiled
cable
1. Adjust the stem length and coil angle so the
search coil rests flat on the ground about 6 inches
in front and slightly to the right of your foot (to the
left of your left foot if you’re left handed).
2. Leave enough slack in the coil cable to allow
the coil to swivel as far as it can in either direction.
The coil wing nut should be tight enough to prevent
the coil from moving.
3. You should now be able to move into your
“search” position by leaning slightly forward and
raising the search coil no more than 2 inches above
the ground. Your arm should still be straight, and
the coil should be parallel to the ground, about 12
inches in front of your foot. The coil angle may have
to be slightly readjusted at this point.
SETTING UP FOR DIVING
Unlike most VLF metal detectors, the CZ-20 works well in salt
water. This capability, along with its deep-seeking sensitivity,
makes it ideal for underwater treasure hunting and wreck diving.
TheCZ-20 iswaterproof toa depthof 250 feet. Remember, always
practice safe diving methods.
(Never hipmount your control housing while diving.)
When diving with your CZ-20, use the shortest stem length
possible, with the extra cable wrapped tightly around the stem,
as closely as possible to the control housing.
SETTING UP

8
1. Adjustthe stemlength asshort as youcan without
having the search coil detect your diving gear.
2. Adjust the search coil parallel to the sea bed,
river or lake bottom.
3. Make sure extra cable is coiled tightly on the
upper stem as closely as possible to the control
housing, with just enough slack near the search coil
to allow it to swivel as far as it can in either direction.
Too much loose cable near the search coil may
generate false signals.
4. Remove the tethered earphone plugs for rapid
pressure equalization as you dive and return to the
surface.
Caution: Hipmounting the CZ-20 control housing is not
recommended for underwater use. The search coil cable may
become entangled with a submerged object, making it difficult
for the diver to resurface quickly in case of emergency.
SETTING UP FOR HIPMOUNTING
For almost-effortless treasure hunting, the control housing is easily
removed from the handle and attached to a belt clip.
SETTING UP
You can hipmount your CZ-20 by sliding the control housing from the
handle and attaching it to your belt. This reduces the weight of the
stem, creating nearly effortless hunting.

9
“Hipmounting” the CZ-20 in this manner takes about half the
weight off the handle and allows the land or shallow-water
Treasure Hunter to search much longer without arm fatigue.
1. Grasp the handle grip firmly with one hand and
the control housing with
the other.
2. Slide the control housing off the mounting
bracket by pulling it toward
you.
3. Slide the belt clip into grooves on the bottom of
the control housing. This
is a snug fit, and you’ll have to bend the clip slightly.
4. Unwrap just enough of the coil cable to allow
for searching.
5. Slip the control housing onto your belt, left side
for right handers, right side for left handers.
NOTE: Because of the extreme sensitivity of the CZ-20 search
coil, hipmounting the control housing may produce a false
signal when the search coil reaches the end of its arc (on the
side that the control box is attached to your belt). Depending
on your stem length and how high you have the housing
hipmounted, the search coil may actually detect the housing.
SETTING UP

10
1
23
4
5
6
CONTROL PANEL
1. VOLUME/OFF: Power on-off and volume control.
Volume is gradually increased from 1-5 settings. From
5-10, loud-target response is held constant while faint
targets continue to get louder.
2. DISC: In the 0-6 positions, the CZ-20 is in the target
mode, which is a silent, no-threshold, motion-
discrimination mode of operation with the ability to
identify and then ignore (“reject”) or accept many
kinds of small metal targets. In the AUTOTUNE position,
the CZ-20 is in an all-metal mode. In this mode, the
CZ-20 has a slightly wider and deeper search pattern;
however, it lacks the ability to discriminate or identify
and reject targets.
3. PINPOINT: A two-purpose, spring-loaded
pushbutton. When pushed and held, the CZ-20 goes
into a no-motion, all-metal mode for precise
pinpointing. This button is also used in conjunction
with the GROUND control during the ground-
balancing procedure.
4. GROUND: Used to electronically cancel the effects
of wet salt and ground mineralization. Proper use of
this control will minimize false ground signals and
ensure that the CZ-20 is operating at its maximum
potential in just about any ground condition including
wet, ocean sand.
5. SENS (Sensitivity)/BATT TEST: In the extreme
counterclockwise position, the battery condition is
checked as indicated by a strong or weak tone and
the red LED’s.

11
TURN ON PROCEDURE
1. Set your controls as follows:
GROUND = “10”
DISC = “0” for normal use in target I.D. mode. (Set
DISC to “Autotune” for deep search, all-metal
AUTOTUNEmode.
SENS = “10”
VOLUME = OFF
2. Hold the search coil waist high, away from any
nearby metal.
3. Turn the VOLUME control to “1” (a brief bell tone is
normal when you turn the VOLUME control on).
4. Then increase the volume to a comfortable level
when the search coil passes over a large, shallow
target.
When your CZ-20 QuickSilver is properly “ground balanced,” it will
have only a minimum response to ground mineralization. Precise
adjustment of the GROUND control is critical for optimum
performance.Thehigherthedegreeofgroundmineralizationorthe
higher the sensitivity setting,the more critical it is to have your
machine properly ground balanced. Once you adjust it in either
the Autotune mode or Target-I.D. mode, you can switch back and
forthbetweenthetwo modes withoutresetting,unlessyou increase
the sensitivity level or go from dry sand to wet sand or vice versa.
You should also recheck your setting occasionally as you search
because ground conditions often change rapidly.
If you have difficulty ground balancing, try reducing your sensitivity
level or moving to another spot just in case you are over a buried
piece of metal. In some areas of high ground mineralization you
may not be able to use the pushbutton method.
6. LIGHT EMITTING DIODES (LED’s): Used to indicate
target signal strength. When the SENSITIVITY control is
in the “BATT TEST” position and both LED’s are fully lit
up, the batteries are fully charged. When both LED’s
are out, it’s time to replace the batteries.
GROUND BALANCING
CONTROL PANEL

12
PUSHBUTTON
This will probably be your method of choice in all but the most
difficult of ground conditions. It’s fast, easy and accurate. You
can use this method in either the Autotune or Target-I.D. mode.
1. With your controls set as in the “Turn-On”
procedure (GROUND control at “10”), hold your
search coil parallel to and 6 to12 inches off the
ground. Press the PINPOINT button and hold it until
you’ve completed step 2. Make sure you’re at
least 3 feet away from any metal objects.
2. Continue pressing the PINPOINT button as you
lower the coil to the ground. Keep your thumb on
the PINPOINT button, and starting at “10,” rotate
the GROUND control clockwise until you hear an
audio tone. Then back off to the exact point where
the tone disappears. Release the PINPOINT button
and you’re ready to search.
3. Always ground balance your CZ-20 in the areas
you intend to search, whether it’s on land or
underwater.
NOTES:
1. If you get an audio response as you first lower the coil with
the GROUND control at “10,” you’re probably over a piece
of metal. Move and try again.
2. If you get a sudden bell tone that is not preceded by an
increasing audio response as you lower the coil, you’re
probably in some very highly mineralized soil or sand. In this
case, it’s best to use the “bobbing” method, paying particular
attention to the notes under paragraph 7.
3. If you don’t get any audio response, or just a very faint one
as you rotate the GROUND control from “10” all the way to
“0,” you’re probably in an area where there’s very little ground
mineralization. Just leave the GROUND control at “10” and
begin searching.
GROUND BALANCING

13
BOBBING 1. AUTOTUNE and the SENSITIVITY control is set so
you can just barely hear a threshold hum. Hold the
search coil parallel to and 6 to 12 inches over the
ground and at least 3 feet away from any metal
objects. Do not use the PINPOINT button during any
part of this procedure.
2. Lower the coil to an inch or two above the
ground and then quickly raise it. Note that as you
lower the coil, the tone disappears then gets louder
as you raise it and finally returns to normal when
you stop it 6 to12 inches above the ground.
Conversely, if you set the GROUND control to “1,”
the threshold hum will get louder as you lower the
coil and disappear when you raise it.
3. Your objective now is to adjust the GROUND
control so that there is no change, or only a
minimumchangeinthe thresholdhum,asyou move
the coil up and down. Start by lowering the
GROUND control to “9.” Lower the coil and raise it
again. One of three things will happen to your
theshold hum:
1) It will fade again as you lower the coil and
increase as you raise it.
2) lt will get louder as you lower the coil and go
silent as you raise it.
3) The hum will remain the same, or if it changes
slightly, the change is the same whether you lower
or raise the coil.
4. If the hum remains the same or changes only
slightly (as in step 3 above), your CZ-20 is properly
ground balanced, and you are ready to begin your
search.
5. If the tone fades as you lower the coil (as in step
1), continue to lower the ground balance setting
in small increments until the threshold hum remains
the same (or changes very little) as the coil is
lowered and raised.
6. If the hum gets louder as you lower the coil, you
GROUND BALANCING

14
GROUND BALANCING
have gone past the correct ground-balance
setting. Increase the ground-balance level
(rotating the control counterclockwise) in small
increments until there is little or no change in the
threshold level.
7. With a little practice, you should be able to
ground balance quickly by “bobbing” the coil up
and down in a continuous movement as you adjust
the GROUND control with your thumb.
NOTES:
1. If you get an audio response as you first lower the coil with
the GROUND control at 10, you’re probably over a piece of
metal. Move and try again.
2. lf you get a sudden bell tone, not preceded by an increasing
audio response, you’re probably in some very highly
mineralized soil or sand. Instead of lowering the coil to an inch
or two above the ground (as in step 2 above), stop just before
you hear the bell tone and ground balance as instructed.
Maintain that coil height as you search.
3. If you don’t get an audio response, or if the hum stays the
same no matter where you set the GROUND controls as you
bob the coil up and down, you’re probably in an area where
there’s very little ground mineralization. Just leave the
GROUND control at “10” and begin searching.

15
SEARCH MODES
Your CZ-20 has two search modes: Target I.D. and Autotune.
Both search modes are “motion” modes, meaning the search
coil must be in motion to detect a target.
AUTO TUNE
Set the DISC control to AUTOTUNE, and you’re in a very sensitive,
wide-scan, all-metal, motion search mode. Since this mode
responds to all metal targets and does not have the ability to
identify or reject objects, this will probably not be your normal
search mode.
The Autotune mode does have some advantages, however,
which make it useful to use in at least three situations:
1. Non-Trashy Areas. Since the Autotune mode has
a wider scan than the I.D. mode, you’re less likely
to miss a good target when using it. Search in the
Autotune mode until you find a target. Pinpoint the
target using the PINPOINT button and then switch
the DISC control to “0” to identify it. The DISC control
is positioned so that you can switch back and forth
between AUTOTUNE and “0” with a flick of your
thumb.
2. Highly Mineralized Soil or Sand. The Autotune
modeis recommendedfor blackand graybeaches
or highly mineralized soil. Under these conditions it
may be necessary to lower the Sensitivity level and
sweep several inches off the ground (see the note
under paragraph 7 on p. 15) Gold nuggets are
generally found in highly mineralized soil so this will
be the search mode of choice for prospectors.
3. All Metals Searching. Evidence recovery teams,
archeologists and professional underwater
Treasure Hunters will often opt for the deep search,
all-metals Autotune mode.
TARGET I.D.
When the DISC control is set in the 0-6 positions, the CZ-20 has
the ability to identify many types of small targets and, depending

16
on the discrimination level, reject or ignore most of them. To better
understand just how your CZ-20 responds to different targets, try
the following:
1. Scatter some sample targets such as coins, rings,
pull tabs, nails and foil on the ground at least 18
inches apart. Include some large targets as well:
jar lids, soda cans, etc.
2. Set the DISC control at “0,” SENS at “5.” Adjust
the VOLUME control for a comfortable level when
you are over a large target.
3. Ground balance the CZ-20 as in the “Ground
Balance” procedure.
4. Hold the search coil about 2 inches above and
parallel to the ground and move it slowly back and
forth across each sample. Remember, the coil must
be in motion to get a response. Keep in mind that
for accurate target I.D., the coil center must pass
directly over the target.
5. Note the different audio responses over the
various targets. Your CZ-20 will respond with a low
tone over most iron or steel targets. Pull tabs and
foil will give a medium-tone response and U.S. coins
will give a high-tone response.
6. Note that an elongated ferrous object such as a
nail will give you a double “beep” as you cross it
from end to end or a single “beep,” if you cross its
center.
7. When you go over a large, shallow target the
CZ-20 will respond with a distinctive bell tone. This
is due to the fact that metal detectors can only
identify small targets. What usually happens is that
the detector circuits will overload and identify a
target as “good” (silver, coins, etc.). Your CZ-20,
however, will alert you to the fact that the target
is big and shallow, and cannot be accurately
identified. (Big deep targets, however, will usually
be classified as a coin. Also be aware that coins
on the surface may set off the bell tone if you get
too close. And the smaller 5-inch coil is more likely
SEARCH MODES

17
SEARCH MODES
to overload than the 8- or 10 1/2-inch coils.
8. Most silver rings will give a high tone. Most gold
rings will fall into the pull tab/foil mid-tone category.
This is due to the unavoidable fact that most gold
rings are conductively similar to aluminum foil and
pull tabs. Some are more closely identical to the
U.S. 5-cent piece; however, the CZ-20 does have
the unique ability to separate those signals from the
aluminum trash signals.
9. Now increase the DISC control to “1.” You will
find that the CZ-20 rejects the small, iron targets and
no longer responds with an audio tone.
10. Continue to increase your DISC control, noting
that with each successive step up you reject more
and more targets. At DISC = “4” for example, you
are in a “coins-only’ mode, ignoring iron, tabs and
foil while accepting U.S. coins.
11. Use the target I.D. decal on the left underside
of your control housing graphically displays which
items are rejected and accepted at each DISC
level. For example, “foil” is placed between DISC
=“2”and DISC =“3.” This meansthatfoil is accepted
at “2” and rejected at “3.”
12. You may expect varying signals over different
Typical CZ-20 Audio Responses

18
targets and at different levels of discrimination.
Note that as you progressively increase the
discrimination level you eliminate more and more
targets.
13. Now switch the DISC control to the AUTOTUNE
position and note the completely different kind of
response. No tone, just a smoother, solid response
over every target.
NOTE: Be aware that due to the virtually infinite variety of sizes,
shapes and alloys of many “good” targets (relics, jewelry,
foreign coins, etc.), they may be identified as just about
anything. For example, a Civil War mini ball may be identified
as foil, or a new Canadian coin as a rectangular pull tab.
Good search techniques are every bit as important as having a
gooddetector.
1. MakesureyourCZ-20 is properlygroundbalanced.
2. Decide which search mode you’re going to use:
TargetI.D.or Autotune.Recommendedstartingpoint:
Target I.D. mode with the DISC control set at “4.”
3.SetyourSENSITIVITYcontrol.Onlyexperiencewilltell
youhowtoset itineverysituation, but you’llprobably
want to run it as high as you can. Recommended
startingpoint:SENSITIVITY=“5.”Ifyou’reintheAutotune
mode, set it so that you can just barely hear a slight
audio hum.
4. Adjust your VOLUME control. Remember that a
setting above “5” will amplify the response of faint
targetssothattheysoundlikeashalloworlargetarget.
Some searchers prefer not to use it above “5” so that
the audio response will give them some ideas as to
the depth and/or size of the target. Recommended
starting point: VOLUME = “5,” then adjust the volume
controlforacomfortable,not-too-loudresponseover
loudtargets.
5. Once you’ve got your controls properly set, begin
your search by walking slowly and sweeping the
SEARCHING ON LAND OR SHALLOW WATER
SEARCH MODES