21
Comprehensive Operating Manual & Guide to Metal Detecting
PRO-TECH
OPERATING IN DISCRIMINATION MODE (continued)
Notice the segment status along the arc, and the discrimination parameters they
represent, vary as you adjust the discrimination level with + or -.
For DISC values (at bottom right-hand corner of screen) up to 40:
- Operation is tone discrimination only
• No targets are eliminated from detection
- Target-IDs less than the DISC value induce a LOW tone
• Represented by shaded segments
- Target-IDs greater than the DISC value induce V.C.O. audio
• Represented by solid segments
for DISC values between 41 and 79:
- Targets in the blank segment region are not detected.
- Target-IDs less than the DISC value induce a LOW tone
• Represented by shaded segments
- Target-IDs greater than the DISC value induce V.C.O. audio
• Represented by solid segments
at DISC value = 80:
- All detected targets induce HIGH tones.
• Represented by solid segments
- There are no LOW tones
- No targets under 80 are detected.
Here is an example of one possible setting:
This discrimination interface for the PRO-TECH was designed especially to allow
distinction between small iron targets and large iron targets. Nails are often
undesirable and will give a lower iron reading than larger iron objects. Users can set
the discrimination setting to reject the smaller iron, but still hear the bigger objects.
Target values of 40 or less are ferrous.
16
PRO-TECH
Comprehensive Operating Manual & Guide to Metal Detecting
Operating in All Metal Mode
The All Metal Mode is more sensitive than the Discrimination Mode, and is used to
find all types of metal objects in the ground. The searchcoil must be in motion for
objects to be detected.
Ground Grab
®
(GG) Computerized Ground Balancing
Naturally occurring minerals in soil look like metal to a metal detector, so you want to
cancel out this mineral signal coming from the ground, and only detect the signal
from metal objects in the ground.
So before using your detector, set it in All Metal Mode and perform the automatic
ground balancing procedure. Press-and-hold the GG button while pumping the
searchcoil up and down over the ground. Release the button when the sound evens
out. The GND BAL number on the bottom right of the screen is the detector's internal
setting which cancels out the minerals in the ground. Different soils in different areas
will require different GND BAL settings, so balance to ground before you search.
Refer to the Ground Balancing section (pg.22) of this manual for a more in-depth description.
Setting the Controls
As you adjust any of the controls, notice that the values on the bottom-right of the
display indicate the settings of the value you are changing.
If you are new to metal detecting, start with the GAIN and THRESHOLD controls at a
low enough setting that you do not hear too many unwanted sounds, like warble or a
loud hum. Set the GAIN at the 12:00 position, or less. Then set the THRESHOLD to
a position where you hear a very slight background hum, or if you prefer, dial the
control just left of that position to a setting where the detector is silent.
Unwanted Noise
Read the section on Electrical Interference.
The PRO-TECH is a highly sensitive device.
It is intended for use outdoors. Indoor operation will subject it to electrical
interference from a wide variety of devices in the home or office.
Sweeping the Searchcoil
As you sweep the searchcoil over the ground, try to keep the searchcoil parallel to
the ground and as close to the ground as you can. Avoid contacting abrasive
materials such as rocks and sand.
Avoid lifting the searchcoil at the end of your sweeps.
Operating in All Metal Mode continued on next page
This value
and higher
will induce
V.C.O.
tones
Values less
than 20 will
NOT BE
DETECTED
Values from 20 to 49
will induce a
LOW
tone
Values from 50 to 100
will induce
V.C.O.
tones
(see p.26 Audio Feedback)
Suggestion: Try changing the
settings, watch the screen and
pass objects over the searchcoil at
each setting. It will quickly become
obvious how these controls work.
