Sierra Gold Trac Owner’s Guide
4
The
THRESHOLD
control knob sets the loudness of the background “Hum”. This background hum
must be maintained at ALL times when searching. In order to hear the tiniest and deepest targets the
THRESHOLD “hum” should be set at the faintest audible level that you can hear. It can be slightly
scratchy, chattery or static like, but it must be constant, so as not to miss small or deep nuggets.
At this point we highly recommend the use of HEADPHONES while prospecting. With headphones, you
can lower the threshold “hum” to an even lower level than you can hear with the naked ear. Therefor a
smaller or deeper signal has a better chance of breaking through the threshold and be hear. Wearing
headphones can also help to cancel out environmental noises like wind etc. and improve your concentra-
tion. If wearing headphones are a bother, you can fi nd small ear buds which work better than no head-
phones. If you are worried about snakes, then you can fi nd headphones with only one ear cup made just
for that purpose. Good headphones also come with volume controls, which also help fi nding the perfect
setting as there is no target volume control on the detector. Headphones with at least 32 ohms will work.
However, headphones with 60 ohms or higher of balanced impedance will give the best results in hearing
the faint signals from tiny or deep nuggets.
Or you are swinging your coil too fast. Slight fading of the threshold is OK as it indicates that you might
be passing over heavier levels of mineralization in your sweep. So threshold maintenance is the key. As
expert Electronic Prospectors will tell you… May your Threshold be with you Always.
The
GAIN
control knob is used to increase or decrease the strength of the target signal coming from
the ground. In other words this control increases or decreases the Sensitivity of the detector to the target
(gold nugget).
This is the most important control on any detector along with the Threshold control and is also the most
dangerous control. Too often a detectorist will just increase the Gain/Sensitivity thinking that this will
automatically help him go deeper. This is NOT necessarily the case. Too much Gain will cause “feedback”
from ground minerals and cause noise which will mask a target signal or actually over-load the circuit.
The key is to use just enough Gain to maintain a smooth and steady threshold Hum with no erratic nois-
es. This “falsing” of the audio is the indication that you are trying to operate with too much Gain. It is best
to use the initial setting “triangle” between 7 & 8 on the Control Knob. If everything is smooth at this set-
ting, then you can creep up a bit at a time. If the ground is severe, then you may have to lower the setting
from the suggested point.
Controls: Threshold-
Controls: Gain + ON/OFF Power-
