Threshold Level - Minelab E-Trac Instruction Manual

audio Menu
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Threshold Level

Range: 1–50
Factory Preset: 30
The constant background 'hum' produced by
the detector is called the Threshold. Variations
in the Threshold help you to hear very small
and deep targets. When a rejected target
is detected, the Threshold sound 'blanks'
(becomes silent) indicating that an undesired
target is underneath the coil.
The Threshold is controlled by Threshold
Level and Threshold Pitch (p. 69). The
correct setting of both Threshold settings will
depend on your hearing and environmental
noise such as wind, waves and machinery.
The Factory Preset for Threshold Level is set
at an appropriate level for E-Trac's built-in
speaker. If the Threshold is too loud whilst
using headphones, use the Threshold Level
setting to reduce the volume.
Adjust the Threshold Level to a faint, audible
hum. This will highlight variations in signal
response which may indicate the presence
of a target. If the soil conditions change the
Threshold Level may need adjustment.
Audio range
that you are able
to hear.
Threshold Level
Small signal Very loud
Just Right signal
If the Threshold Level is too high, accepted
targets will be harder to hear above the
Threshold 'hum' . Small target responses will
become difficult to hear as the Threshold
nears a maximum setting of 50 when there
will be a persistently loud Threshold 'hum' .
Threshold Level
Audio range
that you are able
to hear.
Small signal Loud signal
Too High
masked just audible
If the Threshold Level is too low, the slight
variation caused by a small or deep target
may not be sufficient to hear. Adjusting the
level to below an audible level will ensure
silent operation but could mask the audio
response from small targets.
Audio range
that you are able
to hear.
Threshold Level
Small signal Loud signal
Too Low
now inaudible
Adjusting Threshold Level:
1 Press the 'Menu' button
2 Scroll across to 'Audio' (using the Right or
Left Navigation Button)
3 Scroll down to 'Threshold Level' (using the
Down Navigation Button)
4 Press either the Left or Right Navigation
Button to change the Threshold Level
5 Press the 'Detect' button to exit the Menu
and resume detecting
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