9
Controls
Threshold
The
Threshold
control sets the level
at which the background audio tone is
heard. In most cases, faint target signals
are easiest to hear when the threshold is
set to a low but clearly audible level. A
higher threshold level can result in audio
fatigue. Too low of a threshold level
means that a stronger target signal is
required to produce an audible change.
Threshold
is best deter-
mined at a low gain setting where there is no chatter.
The threshold can be set low enough to effect a “silent
search” audio. Some people prefer silent search to prevent audio
fatigue. If you choose to do this, increase the threshold to the
point where you can hear the threshold tone, then slowly back
off until it is barely inaudible. Reducing the threshold any more
than necessary requires stronger target signals to produce an
audio response. Other controls — including
Gain
,
Ground Bal-
ance
, and
Frequency
offset — are best adjusted with an audible
threshold.
Power/Gain
The
Gain
control increases or decreases the amplification of
the receive signal. Normally, this deter-
mines how deep the detector will “see”
a target.
However, increasing the gain not
only increases the amplification of tar-
get signals, but also that of ground
signals and electromagnetic interference
(EMI) as well. A common mistake is to
assume