7
7
1
1
8
8
ELECTROMAGNETIC INTERFERENCE
Use the Sensitivity Control is to eliminate
Electromagnetic Interference (EMI).
The F4 metal detector is an extremely sensitive
device; the search coil creates its own
magnetic field and acts like an antenna. If
your detector beeps erratically when the
search coil is motionless, the unit is probably
detecting another electromagnetic field.
Common sources of EMI are electric power lines, both suspended and buried,
motors, and household appliances like computers and microwave ovens.
Some indoor electronic devices, such as dimmer switches used on household
lighting, produce severe EMI and can cause the detector to beep erratically.
Other metal detectors also produce their own electromagnetic fields; so if
detecting with a friend, keep two metal detectors at least 20 feet apart.
If the detector beeps erratically, R
R
E
E
D
D
U
U
C
C
E
E
T
T
H
H
E
E
S
S
E
E
N
N
S
S
I
I
T
T
I
I
V
V
I
I
T
T
Y
Y
by pressing the
S
S
e
e
n
n
s
s
i
i
t
t
i
i
v
v
i
i
t
t
y
y
-
-
Pad on the left of the control panel.
In most urban environments, you should be able to search without chatter from
interference at the default sensitivity setting (default setting is the sensitivity level
at power-up, 4 bars), or at one level reduced from default. At maximum
sensitivity, the F4 will “chatter” in proximity to underground or overhead power
lines, or to indoor or outdoor electrical devices. In fact, if you notice rapid
chatter with the searchcoil near the ground, you may be able to trace the
approximate location of the underground power lines by following the chatter.
To manage chatter, which is most likely from electrical interference:
1
1
.
.
R
R
E
E
D
D
U
U
C
C
E
E
t
t
h
h
e
e
S
S
E
E
N
N
S
S
I
I
T
T
I
I
V
V
I
I
T
T
Y
Y
until the chatter stops.
2
2
.
.
Try sweeping it over the ground.
If the F4 chatters while held still, or held up in the air, it may be much
quieter when sweeping over the ground.
3
3
.
.
Operate in AUTOTUNE mode
Interference is much more tolerable in this mode, even at high sensitivity.
SEVERE GROUND CONDITIONS
A secondary use for the Sensitivity Control is to reduce false detection signals
caused by severe ground conditions. While the detector contains circuitry to
eliminate the signals caused by most naturally occurring ground minerals, 100%
of all ground conditions cannot be anticipated. Highly magnetic soils found in
mountainous and gold-prospecting locations can cause the detector to emit
tones when metal objects are not present. High saline content soils and sands
can sometimes cause the detector to beep when no metal target is present.
If the detector emits false, non-repeatable, signals, REDUCE THE SENSITIVITY.
SENSITIVITY ADJUSTMENT
V
V
I
I
.
.
W
W
a
a
v
v
e
e
t
t
h
h
e
e
N
N
a
a
i
i
l
l
o
o
v
v
e
e
r
r
t
t
h
h
e
e
S
S
e
e
a
a
r
r
c
c
h
h
C
C
o
o
i
i
l
l
a. The Nail will not be detected.
b. The Nail has been "Discriminated Out."
V
V
I
I
I
I
.
.
P
P
r
r
e
e
s
s
s
s
t
t
h
h
e
e
“
“
D
D
I
I
S
S
C
C
R
R
I
I
M
M
I
I
N
N
A
A
T
T
I
I
O
O
N
N
+
+
”
”
t
t
o
o
u
u
c
c
h
h
p
p
a
a
d
d
3
3
t
t
i
i
m
m
e
e
s
s
.
.
Five “R”s are now
displayed.
V
V
I
I
I
I
I
I
.
.
W
W
a
a
v
v
e
e
a
a
l
l
l
l
o
o
b
b
j
j
e
e
c
c
t
t
s
s
o
o
v
v
e
e
r
r
t
t
h
h
e
e
S
S
e
e
a
a
r
r
c
c
h
h
C
C
o
o
i
i
l
l
The Nail and Pull-Tab will
not be detected.
The other objects will be
detected with their own distinctive tones.
I
I
X
X
.
.
P
P
r
r
e
e
s
s
s
s
t
t
h
h
e
e
N
N
O
O
T
T
C
C
H
H
t
t
o
o
u
u
c
c
h
h
p
p
a
a
d
d
.
.
A flashing “
▲
” will
appear under the IRON-1
segment.
X
X
.
.
P
P
r
r
e
e
s
s
s
s
t
t
h
h
e
e
D
D
I
I
S
S
C
C
R
R
I
I
M
M
I
I
N
N
A
A
T
T
I
I
O
O
N
N
+
+
t
t
o
o
u
u
c
c
h
h
p
p
a
a
d
d
3
3
t
t
i
i
m
m
e
e
s
s
.
.
The flashing “
▲
” will move
to the 5¢ segment.
X
X
I
I
.
.
P
P
r
r
e
e
s
s
s
s
t
t
h
h
e
e
N
N
O
O
T
T
C
C
H
H
t
t
o
o
u
u
c
c
h
h
p
p
a
a
d
d
a
a
g
g
a
a
i
i
n
n
The “R” will disappear under
5¢ segment.
X
X
I
I
I
I
.
.
W
W
a
a
v
v
e
e
t
t
h
h
e
e
n
n
i
i
c
c
k
k
e
e
l
l
o
o
v
v
e
e
r
r
t
t
h
h
e
e
s
s
e
e
a
a
r
r
c
c
h
h
c
c
o
o
i
i
l
l
.
.
The nickel is detected.
X
X
I
I
I
I
I
I
.
.
W
W
a
a
v
v
e
e
t
t
h
h
e
e
p
p
e
e
n
n
n
n
y
y
o
o
v
v
e
e
r
r
t
t
h
h
e
e
s
s
e
e
a
a
r
r
c
c
h
h
c
c
o
o
i
i
l
l
.
.
X
X
I
I
V
V
.
.
P
P
r
r
e
e
s
s
s
s
t
t
h
h
e
e
N
N
O
O
T
T
C
C
H
H
t
t
o
o
u
u
c
c
h
h
p
p
a
a
d
d
t
t
w
w
i
i
c
c
e
e
.
.
The arrow under the 1¢ segment will flash & then the “R” will illuminate.
X
X
V
V
.
.
W
W
a
a
v
v
e
e
t
t
h
h
e
e
p
p
e
e
n
n
n
n
y
y
o
o
v
v
e
e
r
r
t
t
h
h
e
e
s
s
e
e
a
a
r
r
c
c
h
h
c
c
o
o
i
i
l
l
a
a
g
g
a
a
i
i
n
n
.
.
The penny (the most recently detected item) is eliminated from
detection.
X
X
V
V
I
I
.
.
P
P
r
r
e
e
s
s
s
s
t
t
h
h
e
e
P
P
I
I
N
N
P
P
O
O
I
I
N
N
T
T
t
t
o
o
u
u
c
c
h
h
p
p
a
a
d
d
.
.
Hold one of the metal objects motionless over the search coil.
• All Metal objects are now detected.
• One monotone sound indicates the presence of any type of metal.
• A 2-digit numerical display indicates approximate target depth, in inches.
QUICK-START DEMONSTRATION
(continued)
F4manual-SPREADS(24pg).qx 4/13/11 8:30 AM Page 7
