White’s Electronics Coinmaster GT - Manual (Page 10)

Page 10
Coinmaster GT
Owner’s Manual
zone. Rejecting a zone only affects the audio; the display will
still show target information even if you can’t hear an audible
response.
The CoinGT display includes a backlight for extended hunt-
ing. Press and hold the
On/Off
button to toggle the backlight. In
daylight it can be difficult to tell whether the backlight is on or
off, so a backlight icon is also displayed. The backlight will
reduce battery life by 30% so it’s best to turn it off when not
needed.
More Info
VDI
VDI stands for Visual Display Indi-
cator and is a numeric representation of
the target’s response. So-called VLF
detectors transmit a magnetic field
which is disrupted by nearby metal tar-
gets. The disruption is seen by the
receiver as an increase in signal ampli-
tude (which gives a basic “I found
something!”) but also creates a signal
phase shift. This phase shift usually
indicates the type of target and can be
used both for identifying targets and for
discriminating or rejecting them.
White’s uses a VDI scale of -95 to
+95, where negative numbers corre-
spond to ferrous (iron) targets and posi-
tive numbers to non-ferrous targets. A
chart of typical VDIs is shown on the
right.
There is a lot of overlap amongst tar-
gets. For example, due to the variety of
sizes and alloys, gold rings can give the
VDI SCALE
HOT ROCK
DOLLAR
HALF / LG
QUARTER
DIME
+95
90
85
80
75
70
65
60
55
S
I
L
V
E
R
ZN CENT
CENT
CU-NI CENT
PUL
L TAB
SQ
TAB
NICKEL
FO
IL
IR
O
N
SALT
NAIL
S
LG IRON
C
U
G
O
L
D
F
E
R
R
O
U
S
50
45
40
35
30
25
20
15
10
5
0
-10
-20
-95
SI
LV
ER
RI
N
G
c
LATE CENT
-40
-60
-90
EARLY CENT
GOLD
RIN
G
$2.50 GOLD
$5 GOLD
SC C
AP
SM
N
U
G
G
ET
LE
AD
MIN
IE