Fisher Research Labs CZ-21 QuickSilver User manual

CZ-21 QuickSilver
Operating Manual
Deep Search, Land and Underwater, Target I.D. Metal Detector
FISHER RESEARCH LABS
MCZ21B 060110
ATTENTION:
Damage do to neglect or accidental damage is
not warrantable
IMPACT WARNING:
Impact to the front knobs, the front edge, or the
case will cause the front plate to fracture, resulting
in leakage.
Such damage is not warrantable.
CABLE STRESS:
If you hip-mount the CZ-21, leave slack in the cable
so as not to pull cable taunt at end of sweep.
Damage to coil cable at housing connection is not
warrantable if a result of repetitive, excessive stress.
Copyright© 2010 by Fisher Research Labs, Inc.
All rights reserved, including the right to reproduce this book,
or parts thereof, in any form.
Published by Fisher Research Labs, Inc.
Fisher® is a registered trademark of Fisher Research Labs, Inc.
www.sherlab.com
1465-H Henry Brennan Dr., El Paso, TX 79936 • [phone]

CONTENTS
About Your Detector ..............................................................pg. 1
Condensed Operating Instructions ......................................pg. 3
Headphones ...........................................................................pg. 4
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. 10
Turn on Procedure ..................................................................pg. 11
Ground Balancing ..................................................................pg. 11
Touch Pad............................................................................pg. 12
Bobbing................................................................................pg. 13
Search Modes.........................................................................pg. 15
Auto Tune.............................................................................pg. 15
Target I.D..............................................................................pg. 16
Searching on Land or in Shallow Water ...............................pg. 18
Searching Underwater ...........................................................pg. 21
Pinpointing ..............................................................................pg. 22
Target Identification ...............................................................pg. 23
Target Recovery .....................................................................pg. 27
Recovery Tools........................................................................pg. 28
False Signals............................................................................pg. 29
Battery Replacement .............................................................pg. 33
Maintenance ..........................................................................pg. 35
Battery Door Gasket: Orientation .........................................pg. 36
Where To Use Your Metal Detector In the U.S. .....................pg. 37
Specifications .........................................................................pg. 38
Treasure Hunters’ Code of Ethics ..........................................pg. 40
41
2-Year Limited Warranty
The CZ-21 metal detector is warranted against defects in materials
and workmanship under normal use for two years from the date of
purchase to the original owner.
Damage due to neglect, accidental damage or misuse of this product is
not covered under this warranty. Decisions regarding abuse or misuse of
the detector are made solely at the discretion of the manufacturer.
Proof of purchase is required to make a claim under this warranty.
NOTE TO CUSTOMERS OUTSIDE THE U.S.A.
This warranty may vary in other countries, check with your
distributor for details.
Warranty does not cover shipping costs.
Liability under this Warranty is limited to replacing or repairing, at our
option, the metal detector returned, shipping cost prepaid, to Fisher
Labs. Shipping cost to Fisher Labs is the responsibility of the consumer.
According to FCC part 15.21 Changes or Modifications made to this device
not expressly approved by the party responsible for compliance could void
the users authority to operate this equipment.
To return your detector for service, please first contact Fisher Labs for a
Return Authorization (RA) Number. Reference the RA number on your
package and return the detector within 15 days of calling to:
Fisher Research Labs, Inc.
1465-H Henry Brennan Dr.
El Paso, TX 79936
Phone: [phone] ext.118
Warranty coverage does not include the cost of transporting
the detector back to an owner who is located
outside of the United States of America.

1
ABOUT YOUR DETECTOR
Your CZ-21 QuickSilver is an all-purpose metal detector
engineered for land, beach, salt and fresh-water treasure hunters.
Here are some important features:
1. Leakproof: Submersible to 250 feet.
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. 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
identication.
4. Two Search Modes: A silent running, slow motion
target I.D. mode and a hot, autotune mode for all-
metal searching.
5. VCO No-Motion Pinpointing: Tap the pinpoint button
and the audio tone increases in pitch and volume
as the center of the coil approaches the target.
6. Big-Target Alert: The CZ-21 circuits may overload
on large, shallow targets. A distinctive bell tone
immediately warns you that the target is too large
to identify.
7. Faint-Target Audio Boost: As you increase the volume
level past “5”, strong target sounds remain at a xed
volume while faint, deep-target sounds continue to
get louder.
8. Quick Manual Ground Balance: Tap 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 conditions.
9. Separately Sealed Battery Compartment: Protects
the electronics from accidental ooding.
TREASURE HUNTERS’ CODE OF ETHICS
LET’S PRESERVE OUR TREASURED SPORT!
Laws governing the use of metal detectors are becoming
more and more common. In many countries, the use of metal
detectors is illegal or severely restricted. Don’t let this happen in
your area.
• Always check Federal, State, County and local laws
before searching.
• Respect private property and do not enter private
property without the owner’s permission.
• Take care to rell all holes and try not to leave any
damage.
• Remove and dispose of any and all trash and litter
found.
• Appreciate and protect our inheritance of natural re-
sources, wildlife and private property.
• Act as an ambassador for the hobby, use thoughtful-
ness, consideration and courtesy at all times.
• Never destroy historical or archaeological treasures.
• All treasure hunters may be judged by the example you
set; always conduct yourself with courtesy and consid-
eration of others
40

ABOUT YOUR DETECTOR
2
10. Search Coils: The CZ-21 comes with the 8” coil as
standard equipment, but can also be custom
ordered with the 10” coil. All coils are permanently
attached.
11. Balanced,Comfortableand Hipmountable:Cushioned
arm rest, soft foam grip and a control housing that
slips off the handle and onto your belt.
12. Salt Water Compensation: Salt water is electrically
conductive, and therefore induces a strong
signal in the searchcoil. Unlike most other metal
detectors, the CZ-21 uses Fourier Domain signal
analysis to cancel the salt water signal. Under most
conditions you will not experience any false signals
from salt water. When working in the surf zone at
high sensitivity settings you may hear an occasional
“whisper” which is easily ignored.
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, adjust the controls
for your own specic 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 nds to tell us about. In
the meantime . . .
Happy Hunting,
Fisher Research Labs
39
Batteries.................... Separately Sealed Compartment........... Yes
................................... Type.......................................... (4) 9V Alkaline
................................... Life Alkaline ......................................35-55 hrs.
................................... Nicads10-20 hrs.
Operating Temperature ..... 32° - 110° F
Faint Target Audio Boost .... Yes
Manual Threshold Tuning.... In Autotune Mode
Target I.D. ............................. Three tones plus bell tone for large,
............................................... shallow targets, plus 7 preset DISC.
............................................... control settings
SPECIFICATIONS
Notes:
1. Subject to improvement or modication without notice.
2. Approximate.
3. Pulsegate Unipolar Audio Processing. Advanced Fisher circuitry which allows
silent operation below “audio threshold tone” with no loss in sensitivity.
4. The CZ-21 is a “motion” detector while in the search mode. The search coil
must be moving at least slightly to detect a target.
5. Electro-Static-Insulated to eliminate certain types of false signals.

3
CONDENSED OPERATING INSTRUCTIONS
Factory Pre-Set “Turn-On-and-Go” Marks
Your CZ-21 QuickSilver is simple to operate. Even so, we strongly
recommend that you read this entire manual. You’ll be able to
tune your CZ-21 to your specic needs and conditions.
1. Set all the controls to the red “Turn-On-and-Go”
pre-set:
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 GROUND
setting of “5” is probably not the optimum setting
for the ground you’re searching. The sensitivity level
is set low to reduce false signals caused by ground
mineralization.
Pre-set Audio
Boost mark
at “5”
Salt-water Pre-set
SENSITIVITY at “3”
Pre-set
DISCRIMINATION
at “4”
Pre-set
GROUND at “5”
Figure 1. Factory pre-set turn-on-and-go marks (circled in red or
blue on your CZ-21 control panel) can get you up and running
immediately.
38
SPECIFICATIONS
Length ..................... Extended .................................................... 50”
................................... Collapsed ................................................... 30”
Weight
Complete (with headset)..............5 lb...11 oz. 6 lb...1 oz. 5.4 lb.
Handle and Search Coil.............. 2 lb...6.9 oz. 2 lb...12.9 oz. 2.1 lb.
Control Housing....................................................................... 2.8 lbs.
Frequency ............... 1. Dual, VLF Search 5 KHz and 15 KHz
................................... 2. Audio Target Response
Iron I.D. ..................... 200 Hz (Low tone)
Foil and Tab I.D. ...... 450 Hz (Mid tone)
Coin I.D. 1 KHz (High tone)
Autotune ................. 500 Hz - 1 KHz (VCO)
Pinpoint ................... 500 Hz - 1 KHz (VCO)
Operating Modes
1. Autotune ..... VLF-Motion, all-metal with threshold tone
2. Target I.D .............................................................VLF-Slow Motion,
............................................................... Silent Search Discrimination
3. Pinpoint .................................................VLF, All-Metal, No Motion
Search Coil............... Type ...........................Concentric, Co-Planar
................................... Diameter .................................. 8”, 10.5” or 5”
................................... Shielding ........................................... 100% ESI
................................... Interchangeable .......................................No
...................................
Headset................................................... Waterproof, Piezo Electric
Interchangeable............................................................................No
Ground Balance .......................................... Touch Pad, Manual or
.................................................................. “Preset” Control Markings
Hipmountable Control Housing................................................... Yes
Salt Water/Fresh Water Operation .............................................. Yes
Land Operation............................................................................. Yes
Submersible....................................................................... to 250 feet
8” Coil 10.5” Coil 5”
Fresh-
water
sensitivity
Pre-set
at “7”

4
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 in motion to
detect a target.
4. When you get a good, repeatable signal, pinpoint
the target.
CONDENSED OPERATING INSTRUCTIONS
37
Where To Use Your Metal Detector In The U.S.
National Forest and Federal Lands—Metal detecting is allowed
only by special permit acquired from the federal government.
Each area has a district ofce.
Corps of Engineers, Lakes, Shorelines and Lands—Permission has
been granted only on predisturbed sites, such as beaches and
attached swimming areas. New Corps lakes and lands must be
okayed by the main ofce of the Army Corps of Engineers. Each
area has a district ofce.
State Parks and Lands—Some state parks are open to metal
detecting, but some are not. Always check with the park ranger
before attempting to use your detector.
Bureau of Land Management (BLM) Lands—Some areas are
open for metal detecting, and some are not. Always check with
the district ofce.
City or County Park Lands—Most are open to metal detecting
unless notice is given by a sign or city ordinance. When in
doubt, always check with the city’s Parks and Recreation
Department.
Public School Grounds—Most are open to metal detecting
unless notice is given by a sign, city ordinance, law enforcement
ofcial, or school employee. You should always check with the
school ofce rst.
Privately Owned Lands (Private Property)—Permission required. It
is always best to have the permission in writing.
Historically Marked Lands or Sites—Metal detecting is not
allowed. Don’t even think about it.
Using headphones (not supplied) improves battery
life, and prevents the sounds from annoying
bystanders.
It also allows you to hear subtle changes in the
sound more clearly, particularly if searching in
a noisy location. For safety reasons, do not use
headphones near trafc or where other dangers
are present. This device is to be used with
interconnecting cables/headphone cables shorter
than three meters.
Using Headphones

5
ASSEMBLY
Submersible
Headphones
Control Housing
Target I.D. Decal
Foam Hand Grip
7-foot Search Coil Cable
Fiberglass Upper Stem
Arm-rest Screw
Battery Access Panel
8-inch
Spider
coil
Nylon
Wing Nut
Fiberglass Reinforced
Nylon Lower Stem
Headphone
Plug
Adjustable Arm Rest
Your Fisher CZ-21 requires little assembly. Handle it carefully, care
for it regularly, and it will give you years of dependable service.
1. Remove the headphone, handle and search coil
assemblies from the box. Be careful not to 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 nger tighten.
5. The arm rest may be repositioned for maximum comfort
by removing the arm-rest screw, sliding the arm rest to the
next screw hole and re-inserting the arm-rest screw.
Control Panel
Figure 2. CZ-21 Quicksilver Detector.
36
BATTERY DOOR GASKET: ORIENTATION
CROSS SECTION
The rubber gasket, which ts into the battery door, must be
installed with the larger protrusion (B), toward the battery door.
If you remove the gasket for cleaning, re-install correctly.
Improper installation will result in leakage.
Figure 16. Battery door gasket installation
CASE BATTERY
DOOR
A = Small side to case
B = Large side to battery door
A B

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:
1. Adjust the stem length and coil angle so the search
coil rests at 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.
SETTING UP
ASSEMBLY
Figure 4.
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
Figure 3.
35
MAINTENANCE
Your CZ-21 doesn’t require a lot of care. It’s built with high-quality
materials, and it’s waterproof to a depth of 250 feet. But there are a
few things you should do to keep it in peak operating condition.
Handling
1. Do not drop your detector.
2. Do not drop the housing directly on to the knobs.
Damage caused by impact is not warrantable.
Storage
1. If you’re not going to be using it for awhile, take
the batteries out. Acid damage caused by leaking
batteries can be severe.
Damage from battery acid is not warrantable.
2. Avoid extreme temperatures. Don’t leave it inside
a closed car sitting in the sun or even worse, in the
trunk of a car.
Cleaning
1. Sand and dirt between the coil “ears” and lower stem
will grind away the ears and stem.
2. The headphone ear pads may be removed, rinsed
and squeezed out to remove any sea water salt
build up.
3. Sand, silt or ne dirt between the upper and lower
stems will cause the lower stem to freeze up. Rinse
frequently.
4. Rinse the lower area under the two knobs on the
control panel thoroughly after use in salt water.
5. Always clean and dry the area around the battery
cover seal before opening.
Battery Compartment
1. Remove the battery cover and check for water
after each use in water.
2. Keep the sealing surfaces of the battery cover
and control housing clean and free of scratches
and nicks. Remove and clean the neoprene
gasket frequently. Lubricating the gasket is not
recommended. Clean the gasket with mild soap
and warm water only. Do not use petroleum jelly or
silicone grease at any time.
3. Re-install gasket correctly (see illustration next page)
Screw
Screw Hole
Upper Stem

7
Control housing
Shortened stem length
Extra, coiled
cable
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-21 works well in salt
water. This capability, along with its deep-seeking sensitivity, makes
it ideal for underwater treasure hunting and wreck diving. The CZ-21
is waterproof to a depth of 250 feet. Remember, always practice
safe diving methods.
When diving with your CZ-21, use the shortest stem length
possible, with the extra cable wrapped tightly around the stem,
as closely as possible to the control housing. Never hipmount your
control housing while diving.
1. Adjust the stem length as short as you can 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.
SETTING UP
Figure 5.
34
BATTERY REPLACEMENT
VERY IMPORTANT
Follow these instructions carefully to avoid getting water in the
battery compartment.
1. Tuck in the wires. Do not pinch them in the seal when closing.
2. The battery door will capture the battery holder and self-center
it as you install the door.
3. Tighten the knobs SECURELY.
a. Use a coin.
b. Tighten by hand FIRMLY.
Use maximum MANUAL force.
c. Do Not use a tool.
d. Do Not use a screwdriver.
Torque Specication is 8 in-pounds.
4. If you have removed the gasket, see page
36 for installation instructions.
An improperly installed gasket = a water leak!
5. Submerge the detector in water for 1/2 hour.
a. Remove from water.
b. Dry off the detector
c. Remove the battery door
d. Verify that no water has entered.
This step is necessary to insure that you are applying
enough force to the screws.
6. If you cannot tighten the screws securely by
hand, then use a screwdriver.
a. Tighten the screw a maximum
additional rotation of 15° beyond the
hand-tightened position.
7. Lithium grease is installed between the
contact surfaces of the thumb-screw and
insert in the case.
a. Do not wipe off the grease.
b. With usage, the grease may wear off.
c.Without grease, the thumb-screw may seize up after
tightening. If this happens, reapply a small amount of
lithium grease between the contact surfaces.
15°

8
Caution: Hipmounting the CZ-21 control housing is not
recommended for underwater use. The search coil cable may
become entangled with a submerged object, making it difcult
for the diver to resurface quickly in case of emergency.
SETTING UP FOR HIPMOUNTING
For nearly-effortless treasure hunting, the control housing is
easily removed from the handle and attached to the belt clip
(included).
INSTRUCTION FOR REMOVAL OF CZ-21 FROM HANDLE
WARNING DO NOT DO THIS
Do not push on unit from the back (battery side.). Doing this will
most likely cause unit to release suddenly and y off, impacting
on the control knobs on the oor, and damaging the unit.
THIS TYPE OF DAMAGE WILL VOID YOUR WARRANTY
SETTING UP
Figure 6. You can hipmount your CZ-21 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.
33
The CZ-21 is powered by four, 9-volt transistor batteries located
in the rear section of the control housing. The batteries are sealed
off from the electronics so that accidental water leakage into the
battery compartment will not damage the circuitry. To replace
the batteries:
1. Remove the battery door by partially unscrewing
the two knurled thumb screws. The knurled knobs
are “captive screws” and are not to be completely
removed from the battery door.
2. Remove the battery pack from the Control Housing.
It’s not necessary to disconnect the battery lead
connector. Be very careful not to put any undue
strain on the battery leads.
3. Remove the batteries from the battery pack, and
install fresh alkaline batteries. You may also use
rechargeable Nicads, but expect about half the
battery life.
4. Insert the battery pack into the Control Housing. With
your nger, push the top of the battery pack (with
the leads) into the Control Housing rst, then let the
bottom follow.
5. Make sure the O-ring and both sealing surfaces
are clear and free of debris before reinstalling the
battery cover. THIS IS EXTREMELY IMPORTANT!.
See page 36 for gasket orientation.
6. Finger tighten the thumb screws, then carefully
tighten again 1/4 turn with a coin or screwdriver.
BATTERY REPLACEMENT