As discussed before, the discriminate mode is used to filter unwanted targets from good targets.
The principle behind this is pretty simple. The detector sends out a signal and then receives it
back creating a small electronic field. As metal passes through the field that the detector
generates, it causes a change in the received signal. The amount of change that each type of
metal causes is fairly constant; therefore, we can tune our detectors to miss targets that we don’t
want to find. The change is based on the amount of conductivity of each target type. The general
list of conductive targets is as follows: iron, foil, nickels, gold jewelry, pulltabs, screw tabs,
pennies, and silver coins starting with dimes and working up to silver dollars. This list is meant
to be a guide only. There is a point that some pulltabs, nickels, and gold jewelry overlap. Also,
the depth of the target and its orientation in the ground can change the received signal. A coin
that is flat to the coil will produce a better signal than a coin that is on edge. Take some time to
try different combinations of depths and orientations of your targets to find out how your
detector responds.
We are now ready to discriminate targets from each other. We will start with the DISC LEVEL
at ALL METAL. Please notice that the DISC LEVEL knob has words that correspond to the
items that are discriminated out. All of your targets will respond with a good audio signal at the
ALL METAL setting. Next, we will turn the DISC LEVEL up to the 5¢ setting. This level is
typically high enough to knock out the nickel. At this time, the iron target and the nickel should
give no response, while most of the pulltabs, the zinc penny, and the quarter will give a solid
response. Next, turn the DISC LEVEL knob just past the TAB marking. At this time, most or all
of the pulltabs should not give any audio signal. The zinc penny and the quarter should give a
strong signal. Now, roll the DISC LEVEL all the way to SCAP. Notice that the penny has
stopped responding and only the quarter is still responding. The discrimination will not go high
enough to lose most of the silver coins. When you are done with your air test, turn the DISC
LEVEL knob counterclockwise to the IRON position.
This air test is designed to quickly show you how your discriminate mode works. Each machine
may be a little different from all of the others, so you may want to take some time and try
different targets to find responses of your machine. At a later date, you may want to build a test
garden to test your detector in the field.
Activate TRIGGER SWITCH Mode
Your Tejón uses a TRIGGER SWITCH to change the operating mode. The TRIGGER SWITCH
is a three-position switch that is springloaded on both ends and will always return to the center
position when released (switch is located underneath housing).
The center position is the regular discriminate and is controlled by the lower discriminate knob
marked DISC LEVEL. The knob is used to set the amount of discrimination that you would like
to hunt with or to place the Tejón in a slow retune all metal mode.
Pulling the TRIGGER SWITCH toward the handle will place your Tejón into the pinpointing
mode. This is a fast retune all metal mode. While the switch is pulled, you will hear a threshold
tone.