GM24k Controls
Goldmaster 24k User Manual 11
SAT Level
SAT adjust
(hold)
Hot Rocks
Hot rocks are mineralized rocks
that can
be heard because they are different in min-
eralization than the surrounding matrix or
body of ground. Negative hot rocks, such
as magnetite, tend to give a “boing” sound
when the searchcoil is passed over them.
The greater the difference between them
and the ground, the louder the “boing”.
Positive hot rocks, such as maghemite tend
to sound just like any other metal target,
such as a nugget and can give a
zip-zip
sound. Positive hot rocks will test any pros-
pectors patience. The
GM24k
will reduce
the effect and help to identify many hot
rocks.
(More on page 19)
SAT Speed Control
The variable
SAT
(Self Adjusting Threshold)
speed
control adjusts the speed that the
GM24k
recovers its threshold hum when the searchcoil
passes over changes in mineralization. This set-
ting is adjusted by holding the MUSIC button
and then adjusting the SAT up or down between
0 (off), 1 (medium), or 2 (fast). The letters “Sa”
will display when adjusting SAT.
SAT Adjustment
The Initial Setting is
1
(medium), appropriate for
mild-to-moderate ground mineralization. When
you encounter fast changes in ground minerali-
zation or deeper, larger hot rocks, you may either
get false signals (positive ground) or lapses in the
THRESHOLD hum (negative ground). Increas-
ing the SAT control setting to
2
will speed up the
auto adjustment of the THRESHOLD “hum” and
reduce this interference. At the same time, you
should slow down your sweep speed to help SAT
do its job to maintain a smooth threshold.
Remember, overall depth will be diminished
with a faster SAT speed, but if the ground is too
noisy to separate a good target from a false sig-
nal, it is better to operate with a little more SAT
speed than to lose a target altogether. This is
the same logic that was used in describing the
SENSITIVITY control. Lowering the gain will
reduce overall depth, but by doing so you can
also improve your performance and find more
nuggets in the long run. For best results, set your
SAT speed JUST high enough to cancel out false
signals from ground mineralization and set the
SENSITIVITY control JUST high enough to
maintain maximum depth without having false
or erratic behavior.
