Operating instructions
mode. However,
if
ground effect
is
a problem on the meter channel
or
interferencE
occurs
as
previously described (B)
you
should reduce
the
Sensitivity Setting.
6a.
In
the
METER
DISCRIMINATE
mode
the
DISCRIMINATE
LEVEL
does·notfunction
7a. In the
METER
DISCRIMINATE
mode
the
detector
operates through
two
Channels.
The
audio
channel ground excludes, and the meter channel discriminates.
Both
these
channels are pre-set
so
no adjustments are necessary.
8a.
Lower
the
search head
to
the
ground. Ensure
that
the search
head
is
kept level
with
the ground. Ensure
that
the correct
tuning
level
has
been set and then commence
searching. sweeping
in
rhythmic
arcs
from
one side
to
another, and advancing
about
six inches
after
each
sweep.
ga. Every metal object
within
range
of
the
detector
will
give
an
audio response, and
the
user should
first
concentrate on recognising variations in audio signal level.
10a. Once a target
has
been recognised the user can then consult the meter response.
With
practice
the
recognition
of
a signal and its analysis become synchronised and
it
is
possible
to
disregard signals caused
by
iron and
continue
sweeping.
A signal caused
by
'iron
will
give
an
audio signal,
but
the
meter
will
swing
left
towards
the
REJECT
end
of
the meter scale.
The meter channel
is
not
as
sensitive
as
the
audio channel and some signals
will
give a clear
audio
response
without
a noticeable
meter
indication. The golden rule should always be:
If
it
is
not
rejected
by
a clear negative response
the
target should be investigated.
However
to
optimise
on the range
of
the
detector
and its analytical abilities,
follow
this procedure:
(1)
After
receiving a target response when sweeping note exact location
of
target.
(2) Move search head
two
to
three feet away
from
the
object.
(3) Place
the
search head on the ground and retune
the
detector
by
operating
the
ADC
switch.
(4) Keeping
the
search head on the ground
sl
ide the head back over the target object.
This
method
should increase the meter response because
the
search head
is
nearer
to
the
object, the
detector
is
at its
optimum
tuning
level, and ground
effect
cannot interfere
with
the meter channel
because the gap between the search head and the ground
is
constant, i.e. nil.
The meter channel
is
set at a level
which
guarantees
that
there can be no
loss
of
depth
or
response
to
silver, copper
or
gold objects, however small
or
thin
in section. Because response
to
these objects
has
been taken as the overriding
priority
the
detector
will
give a positive response
to
pull
tabs,
or
even
large pieces
of
silver paper.
A higher level
of
discrimination
can be obtained
by
operating in
the
G-D3 mode. However, operating
at Discriminate levels beyond Mode
D2,
Discriminate Level 5 may result in
depth
losses
on certain
objects such
as
cupro-nickel
or
thin
section jewellery.
The Discriminate level
of
the
meter channel which
is
fixed
as
previously described
is
equivalent
to
Mode
D2
Discriminate Level 5.
OPERATING
IN
THE
ANALYTICAL
MODES
To
operate in one
of
the three analytical modes:
G -
D1
G - D2
G -
03
,
it
is
necessary
to
decide
which
level
of
discriminate
is
requirea4'or' the site you
wi:-:
:':"J.
o.earching.
For
instance,
or
a ploughed
field
where silver paper and ring pulls
are
not
a problem the user
will
probably
select G-D1. On another site,
say
a picnic
si~e
where silver paper and some ring pulls abound,
the
user
will
probably
select G-D2
or
even G-D3.
Always
though,
use
as
little
discrimination
as
the
site allows.
Follow
steps 1-3
"Setting
the Tuning Level
of
the
Detector"
and then se!ect
the
most suitable mode
by
following
this
procedure:
4b. Lower
the
search head
to
the
ground. Keep at a steady height above the ground and
ensure
the
Tuning Level
is
set
correctly
by
operating
the
ADC
switch
firmly
to
the
left
or
right
and then release
it.
5b. The
principle
of
the
Analytical'Moce
operation
is
to
search in the
Ground
Exclude
Mode
(Gl
and then analyse any target
by
switching
to
the relevant Discriminate
Mode (D).
6b.
To
select the (G) mode
press
the
ADC
switch
to
the
left
and then release
it.
7b. When a target object
has
been located,
note
the
location
of
the
signal and take the
search head away
from
the object
at
least
two
to
three feet. Select
the
(D) mode and
ensure
the
tuning
level
is
at
the
correct level
by
pre~sing
the
ADC
switch
to
the
right
and
then
release
it.
:C;b.
Carefully rescan
the
target object, ensuring
that
the search head
is
kept level
with
the
ground.
6