Stabilizer; Signal Peak / Adjusting The Pitch Variation Of Target Signals - Minelab GPX5000 Instruction Manual

Stabilizer

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GPX 5000 Range
1–20
GPX 4800 Range 1–10
Factory Preset 10 (GPX 5000), 5 (GPX 4800)
The Stabilizer function controls the point at which faint
variations in the Threshold begin to be heard. These faint
variations can either be ambient noise or faint target signals.
As you increase the Stabilizer control faint signals will
become louder but the noise level will also increase. This
may potentially hide a desirable target signal. The Stabilizer
allows you to mask faint variations, to provide a perfectly
stable Threshold, improving your ability to identify faint
target signals.
The Stabilizer is best left in the Factory Preset position
until the soil conditions are determined. Once the Rx Gain
Tip: By turning the stabilizer
level has been set for the local conditions, and other audio
control close to minimum
settings have been selected, the Stabilizer can then be used
(<3) the threshold will be
to fine tune the Threshold stability.
very stable, but you will
lose a lot of sensitivity to
To find the optimal position of the Stabilizer ensure the coil
smaller targets. This can be
is being swept across the ground. One number below the
a desirable feature in certain
point at which the Threshold begins to chatter is generally
scenarios, such as looking for
the best setting.
large nuggets in a high-trash
area, or using the GPX Series
The effect of the Stabilizer could be seen as having a
to search for coins or treasure.
similar effect to that of the Rx Gain control. However, the
Stabilizer affects the audio processing only and does not
We recommend the best order
change the Receive (Rx) signal, so it should be used as a
for setting these controls are:
final stage fine tune.
1 Select an appropriate
After making any adjustment to the Stabilizer, if the ground
Search Mode.
conditions change or you wish to change coils, you may
2 Select the desired
need to reset the Rx Gain. Before doing so, return the
Audio Type.
Stabilizer to the Factory Preset setting. This will ensure
you select the most appropriate Rx Gain level to suit the
3 Adjust Rx Gain until
conditions and then you can fine tune the Stabilizer.
the threshold starts to
break up.
Note: Regardless of which Audio Type is selected, the optimal
4 Adjust Stabilizer to smooth
setting of the Stabilizer is one number below the point where
out the threshold.
the Threshold begins to chatter.
Signal Peak
Adjusting the pitch variation of
target signals.
A high Signal Peak setting
Rising Tone will increase the pitch variation
of the target signal. However,
in highly mineralised ground
Pitch Variance
this high variance of signal
may make the detector
appear noisy.
Pitch Variance
Falling Tone
Reduced Pitch Variance (Large Target)
A low Signal Peak setting will
decrease the pitch variation so
target signals will sound more
monotone.
Note: People who suffer high
frequency hearing loss may
prefer to use a Signal Peak
setting of 10 or less.
GPX 5000 Range
1–20
GPX 4800 Range 1–20
Factory Preset 16
You are more likely to hear a target signal when both the
volume and the tone of the target signal change upon
detection rather than the volume alone.
A target signal on the GPX Series is normally a two-tone signal.
A target signal which first falls in pitch and then rises
is normally a deep target. A 'rise and fall' of the pitch
characterises a small target.
The Signal Peak control sets the level of variance between the
high and low pitch of the signal.
Pitch Variance
Pitch Variance
Increased Pitch Variance (Large Target)
Pitch Variance
Pitch Variance
Reduced Pitch Variance (Large Target)
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Rising Tone
Falling Tone
Rising Tone
Falling Tone