Gain and Threshold in All Metal Mode
Adjustment of these two settings is critical for a noise-free and high performance operation of
the device. It is possible to obtain an average performance with the default settings. However,
these settings need to be adjusted in order to perform deeper searches as ground and
surrounding conditions allow or to perform search under challenging conditions.
In the All Metal mode, search is performed with a continuous humming sound in the
background, also referred to as the threshold sound. The loudness of this hum directly impacts
the detection depth of smaller and deeper targets and it is adjusted by the threshold setting. If
the threshold is set too high, the target signal may not be heard. On the contrary, if it is too low,
you give up the depth advantage this setting offers. In other words, weak signals of smaller or
deeper targets may be missed. Threshold setting comes with the default value at each startup
(not with the last adjusted value). It is recommended for average users to leave this setting at its
default value and for experienced users to adjust to the highest level where they can still hear
the weak target signals.
In the All Metal mode, although the gain setting seems like it is behaving similarly to the
threshold, it actually causes an increase or decrease in the popping sounds and false signals. It is
important to set the sensitivity setting to the highest level possible where no major popping
sounds are heard. For example; if the noise level is suitable for searching and is the same at
sensitivity levels 20 and 50, then 50 should be preferred. Using the factory default levels will be
a good starting point until you get familiar and experienced with the device.
If the device is stable but too noisy, the threshold setting should be decreased. However, if it
sounds erratic and there is too much popping, the gain setting should be lowered.
Since the threshold setting is not available in the discrimination modes, you can increase the
depth of the device or ensure noise-free operation on different grounds only by using the gain
setting.
In order to adjust the gain in the discrimination modes, first ground balance while the gain is at
its default setting. After ground balance is completed, hold the search coil still or swing over the
ground at search height. Reduce the gain if device receives noise. If not (ensure that the ID
FILTER is also at its default settings when checking this), increase the gain gradually until there is
no popping sound. If the device starts to receive noise during searching, reduce the gain
gradually.
Gain in Discrimination Modes
Gain and Threshold
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