Cobra Beach Magnet User manual
www.kellycodetectors.com
1085 Belle Avenue, Winter Springs, FL 32708
407-699-8700
COBRA
B E A C H
M A G N E T
High Performance
Under Water Metal Detector
with Ultra Deep 10" Search Coil
Owners’s
Manual
Super Advanced
System
High Powered,
More Depth!
112
The COBRA Beach Magnet is a high powered underwater
metal detector that is easy to use. With a fully automatic circuitry
that handles the ground balancing and tuning for you. The COBRA
Beach Magnet is perfect for hunting on any wet beach or where
high moisture becomes a problem.
Exclusive Features of the COBRA Beach Magnet:
• State-of-the-art high reliable circuitry.
• Full automatic tuning.
• Full automatic ground balancing.
• Full range VLF discrimination.
• Target response light.
• Volume control.
• Detection depth control.
• Audio battery test.
• The Detector is fully water resistant to 132 feet.
GLOSSARY OF TERMS
Air Test - A sensitivity test performed by
outwardly moving various sized metal
samples under the metal detector search-
coil to measure the distance limit of detec-
tion. This test is not always an accurate
indicator of ground depth penetration ca-
pability. (See Bench Test)
Alkaline - A class of battery characterized
by the ability to sustain longer periods
of current drain and greater storage life
when compared to the standard carbon-
zinc type.
Bench Test - An air test to determine at
what discriminate settings various metal
samples are rejected or accepted. The test
is conducted in a non-metallic area.
Cache - Any intentionally buried or se-
creted hoard of valuables.
Conductivity - The measure of a metal
target's ability to allow eddy current gen-
eration on its surface.
Control Housing - A metal or plastic box
which holds circuit boards, indicators, me-
ter, controls and power supply.
Depth Penetration - The greatest mea-
sure of metal detector ability to transmit an
electromagnetic field into the soil matrix
and produce a target signal.
Discrimination - Adjustable circuitry
which ignores or nulls audio responses
from a specific conductivity range allow-
ing positive responses to be heard from
metals higher in conductivity above the
discriminate control setting. Designed
primarily to eliminate audio response from
trash metals.
Double Blip - A signal characteristic com-
mon to elongated ferrous targets such as
nails detected in the all-metal non-motion
mode.
Faint Signal - A sound characteristic of
targets that are sometimes deeply buried
or very small in size.
False Signal - An erroneous signal cre-
ated by automatic retuning overshoot,
ground voids or highly mineralized hot
rocks.
Ferrous - Descriptive of any iron or iron
bearing material.
Metal - Metallic substances; iron, foil,
nickel, aluminum, gold, brass, lead, cop-
per, silver, etc.
Metal Detectorist - A person operating
a metal detector in the field. This name is
preferred by many over Treasure Hunter.
Mineralized Ground - any soil that
contains conductive or non-conductive
components.
Motion Discriminator - A detector type
that requires searchcoil motion to activate
its simultaneous ground balance and dis-
criminate functions.
Non-Ferrous - Not of iron. Metals of the
precious class (i.e. gold, silver, copper,
etc.)
Pinpointing - Finding the exact target
location with respect to a searchcoil's des-
ignated center. Accomplished by interpret-
ing the centers of audio response width in
perpendicular direction or scans.
Searchcoil - A circular (can be other
shapes) plastic housing containing single
or multiple transmit and receive windings
in a specific orientation or configuration to
emit and receive signals from ground and
targets. (also called loop or coil).
Searchcoil Cable - An electrostatically
shielded cable of conductors (wires) which
convey signals to/from the searchcoil or
control housing.
Sensitivity - The measure or capacity of
a metal detector to perceive changes in
conductivity within the detection pattern.
Generally, the more sensitivity a detector
can smoothly provide, the more depth it
will achieve.
Signal - An audio response or visual in-
dication alerting the operator that a target
has been detected.
Slow Motion - A description of searchcoil
speed required to operate the motion dis-
criminate mode.
Sweep - the motion one employs in mov-
ing the coil.
310
ASSEMBLY —
The detector is shipped fully assembled in one carton. Only two
adjustments are necessary, and no tools are required.
1. Turn the search coil to the scanning position. It may be nec-
essary to loosen the knobs securing the coil and then tighten them
again. Make sure that the knobs are tightened (by hand) securely
after the search coil is positioned.
2. Install (6) "AA" batteries and then the detector will be ready
for use.
MIND YOUR MANNERS
Filling holes and obeying NO TRESPASSING Signs are but 2 require-
ments of a dedicated metal detector hobbyist. A sincere request that
KELLYCO makes to every user of a detector is that each place searched
be left in a better condition that it was found. Thousands of individuals and
organizations have adopted this formal.
Metal Detector Operators Code of Ethics:
• I will respect private and public property, all historical and archaeological
sites and will do no metal detecting on these lands without proper permis-
sion.
• I will keep informed on and obey all laws, regulations and rules governing
federal, state and local public lands.
• I will aid law enforcement officials whenever possible.
• I will cause no willful damage to property of any kind, including fences,
signs and buildings and will always fill holes I dig.
• I will not destroy property, buildings or the remains of ghost towns or other
deserted structures.
• I will not leave litter or uncovered items lying around. I will carry all trash
and dug targets with me when I leave each search area.
• I will observe the golden rule, using good outdoor manners and conduct-
ing myself at all times in a manner which will add to the stature and public
image of all people engages in the field of metal detection.
Warning!
Any metal detector may detect underground power lines, explosives or
other items which when struck could cause personal injury. When search-
ing for treasure with your detector, observe these precautions:
Do not hunt in an area where you believe there may be shallowly buried
underground electric lines or pipes.
Do not hunt in a military zone where bombs or other explosives may be
buried.
Avoid striking any line known to be or suspected to be carrying electrical
power.
Do not disturb any pipeline, particularly if it could be carrying flammable
gas or liquid.
Use reasonable caution in digging toward any target, particularly in areas
where you are uncertain of underground conditions.
CONTROL PANEL —
TRASH ELIMINATOR
DETECTION
DEPTH
INCREASE
OR
DECREASE
POWER
ON/OFF
BATTERY
TEST
INSERT ROD
TO JOIN TOGETHER
COIL KNOBS
VOLUME
CONTROL
TARGET
LIGHT
• FACTORY RECOMMEND
STARTING POINT
(Pre-Set Position)
• FACTORY
RECOMMEND
STARTING
POINT
(Pre-Set
Position)
• FACTORY
RECOMMEND
STARTING
POINT
(Pre-Set
Position)
49
IN THE FIELD TIP FOR USING YOUR COBRA BEACH MAGNET
2. The Cobra Beach Magnet is an Ultra Slow Motion Metal De-
tector. When using this detector the coil must be in motion to detect
any target. A sweep speed of about 2 feet per second is perfect.
You can hunt as fast as you want or as your pace dictates.
3. Correct arm position. Adjust
the lower stem so that your arm
is hanging in a comfortable posi-
tion by your side with the coil
about 1 inch off the ground.
1. Always keep the bottom of the coil level with the ground. Try
to maintain coil 1 inch off the ground at all times. You do not need
to scrub the ground with the coil.
2
FEET
PER
SECOND
OPERATION OF THE BATTERY TEST CONTROL –
Before testing the batteries you must first make sure the
Volume Control is set to its maximum position. Now you simply ro-
tate the Detection Depth Control counterclockwise until it "clicks
into the battery test mode", good batteries will give a loud audio
and very bright target light. If the batteries are getting weak you
will only get a faint audio volume and the target light will be dim. If
you can't get any audio or target light when testing the batteries,
it is time to replace them. Use only alkaline type batteries for the
best performance and run time. You can also use good quality re-
chargeable batteries,
but run time will be
somewhat less.
Testing the battery with the Detection Depth Control. . .
Locate the battery door cover and
loosen both stainless steel screws
(see inset) remove door and care-
fully remove (6) "AA" batteries from
the installed battery holder. Replace
with fresh "AA" batteries and please
pay careful attention to the plus and
minus direction of each battery. Place
holder back in battery box. Pay care-
ful attention to the rubber battery door
seal that it is properly aligned and not
pinched between door and battery
box and tighten down both stainless
steel battery door screws.
Installing the Batteries:
Caution: DO NOT Remove the two wa-
terproof seal/strain relief's where the head-
phone wire and search coil wires exit . . .
Note: DO NOT over tighten the screws!!
58
USING THE COBRA BEACH MAGNET UNDERWATER
METAL DETECTOR —
LOWEST
AUDIO
PITCH
LOWEST
AUDIO
PITCH
HIGHEST AUDIO PITCH
(Dead Center)
The Cobra Beach Magnet is a slow motion type detector, in
other words the coil must be in slow motion to respond to any tar-
get. By simply moving the coil back and forth over the ground this
motion will activate the automatic ground balance and tuning cir-
cuits of you detector and keep it at its optimum tuning levels. When
scanning the ground try to keep the search coil about 1 inch off
the ground. DO NOT scrub the ground, you may get some "False
Signals" by doing that. Please refer to the following drawings for the
correct way to sweep and hold your metal detector.
2
FEET
PER
SECOND
Simply moving
the coil back
and forth over
the ground.
Keep the search
coil about 1 inch
off the ground.
OPERATION OF CONTROLS —
To operate and turn on the Cobra Beach Magnet simply turn the
Power/Volume Control fully clockwise. Turning this same control
counterclockwise will lower the headphone volume.
TIP: Adjust the headphone volume that is comfortable for your per-
sonal hearing.
After you have turned on the Cobra Beach Magnet you should
now adjust the Detection Depth Control and the Trash Eliminator
Control to their Pre-set positions. This is only a starting point and
will help you get familiar with your new Cobra Beach Magnet
underwater detector.
Power ON and OFF
Volume Switch.
E
• FACTORY RECOMMEND
STARTING POINT
(Pre-Set Position)
76
OPERATION OF THE TRASH ELIMINATOR CONTROL –
The Trash Eliminator Control is used to reject or discriminate
unwanted trash targets. When the control is set to '0' your Cobra
Beach Magnet will be in the All-Metal Mode and will respond to all
targets. When you increase the control to a higher number the de-
tector will begin to reject small iron targets first then most small foil
pieces and then pull tabs. Study the below chart to get a better un-
derstanding of the different levels that trash target are eliminated.
Note: Most Eliminated Trash Targets will give a broken or chattered sound when
discriminated, this is normal and is a design feature of this underwater detector. It
was designed this way so you can easily identify trash targets. Some trash targets
will give No sounds at all. Practice using the Elimination Control by putting some
different coins and trash items on the ground in a straight line about 10 inches
apart. Pass each item once and then come back and increase the elimination
control knob by one number and listen to the changes in the audio response on
the trash targets as you keep increasing the control by one. Remember even good
targets can be eliminated at the maximum discrimination settings.
• FACTORY RECOMMEND
STARTING POINT
(Pre-Set Position)
TIP: Always keep
the Trash Elimina-
tion Control at its
lowest possible
settings so you will
not reject nickels
and small gold
rings . . .
OPERATION OF THE DETECTION DEPTH –
• FACTORY RECOMMEND
STARTING POINT
(Pre-Set
Position)
By starting out at the Pre-set point the COBRA Beach Magnet
is set at the normal detection depth range. The normal range is
good for most soil conditions, but by increasing this control clock-
wise to the maximum position you will get better depth on older
coins. This control is extremely helpful in elimination false signals
caused by high minerals. If you are experiencing false signals you
should decrease this control until these signals are minimized.
TIP: Try running the COBRA Beach Magnet in the highest
Detection Depth Range that you can (with minimal false signals)
so the detector will give you maximum coin depth.
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