White’s Electronics MX5 - Manual (Page 17)

Page 17
MX5
Owner’s Manual
Some soils, especially coastal beaches, contain salts which
appear as a conductive target. Wet salt sand and seawater are
especially conductive and respond with a VDI of around +5
which is in the region of foil. While we could just notch out this
portion of the disc mask to ignore salt responses, the presence
of these responses (even though ignored) will still tend to mask
out desired target responses. In
Beach
mode, the MX5 Auto-
Trac ® system is expanded to track all the way up to the salt
region (VDI=+5):
Because the track range now includes the entire ferrous
region, it is possible for iron targets to cause tracking errors.
Therefore, if a target gives an initial response and then quickly
fades away on subsequent short sweeps, it is likely an iron tar-
get. Using Pinpoint mode will lock tracking and allow you to
zero in on the target. You may first need to move off the target
and bob the coil a couple of times to re-establish a correct
ground balance point, then switch to Pinpoint mode.
All-metal VCO
For both all-metal and pinpoint modes the audio response
can be set to VCO by simultaneously pressing the
Pinpoint
and
 buttons. VCO audio provides a variable pitch response
which rises as the target strength increases. Non-VCO audio
provides a variable loudness response and is selected by press-
ing the
Pinpoint
and  buttons. The human ear is more sensi-
tive to pitch changes, so with VCO audio very faint responses
are easier to discern.
-95 +95
0
Salt Track Range
Pure ferrite
P
ur
e
s
al
t
F
e
r
r o
u s
N o
n -
F e
r
r
o
u
s