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Notch Filter
Notch Filter is the ability of the device to discriminate single or multiple Target IDs by not
emitting an audio response for them or giving a low iron tone (please refer to iron tone in
notch filter).
Although Notch Filter may seem similar to Disc. at first glance, these two settings have
different functions. While the Disc. filters out all IDs between 0 and the set value, the Notch
Filter filters IDs individually.
With the Notch Filter you can reject a single ID or multiple IDs at the same time. This process
does not affect any IDs below or above the selected IDs. For example, you can filter out IDs
between 31-35 as well as 50 simultaneously.
How To Use The Notch Filter
When Notch Filter is selected from the Expert Settings, first, the current Disc. value will be
displayed on screen and discriminated ID range will be shown on the ID scale with lines. For
example, if the Disc. is set to 15, when you select Notch Filter, number 15 will be displayed
on screen corresponding to 8 lines on the ID scale (every 2 consecutive IDs are represented
with 1 line). Notch Filter cannot be used within the Disc. range. In other words, if the Disc. is
set to 15, Notch Filter can only be applied to IDs 16 or higher. If you want to Notch Filter IDs
15 or below, first you need to change the Disc. value.
The Notch Filter rejects or accepts IDs with the help of the cursor at the top of the screen.
To move the cursor on the scale, plus (+) and minus (-) buttons are used. The cursor blinks
while it is moving on the scale. When you are on the first ID that you want to reject, press
the SELECT button once. This ID is now rejected and it is shown on the screen with a line. If
you want to reject multiple IDs, continue to press the plus (+) or minus (-) button. If non-con-
secutive IDs want to be rejected, push the SELECT button once to have the cursor blink for
navigation on the scale and repeat the process above. The cursor will appear where you left
it the next time you use the Notch Filter.
To give an example; let's say you want to reject IDs between 20-25 and the cursor is at 10.
Press the plus (+) button until you reach number 20. Then push the SELECT button once.
Number 20 will be marked with a line. When you reach number 25 using the (+) button
again, IDs between 20-25 will be filtered out and they will be shown on the ID scale with 3
lines (every 2 consecutive IDs are represented with 1 line).
To accept back the filtered IDs, select Notch Filter in the menu. The cursor will appear where
you last left it. Using the plus (+) or the minus (-) button, select the ID you want to accept and
push the SELECT button. Then, using the plus (+) or minus (-) button again, unfilter the IDs
back in. 1 line will be erased for every 2 consecutive IDs accepted.
Iron Tone in Notch Filter:
This will enable you to get a low iron tone for your notched out target IDs instead of silencing
them. To use this feature, first select Fe Vol. from the menu and using the plus (+) button
select the iron tone volume between n1-n5. n5 is the maximum level and the iron volume
will be reduced as you go down but it cannot be silenced completely.
Notch Filter adjustment applies to the selected search mode only. The change does not
affect the other modes.
IMPORTANT!
If you are using the Standard ID scale and you change the operating frequency
of the device, you may need to re-adjust the Notch Filter values according to the IDs you will
get in the new frequency.
Audio Tone
Allows you to change the target audio response tones and the threshold sound according
to your preference. For each metal group (Fe, Gold/Non-Fe, Non-Fe) the frequency can be
adjusted between 150 Hz (15) and 700 Hz (70).
When Audio Tone is selected from the Expert Settings, names of the metal groups men-
tioned above will appear at the bottom of the screen and the selected one will be framed.
To select another group, just press the SELECT button. Then use the plus (+) or the minus
(-) button to change the audio frequency.
Audio Tone adjustment applies to the selected search mode only. The change does not affect
the other modes.
Tone Break
It is used to adjust the break points of the target response tones on the Target ID range.
Default Tone Break points in the
IMPACT
will vary according to the search mode. By using
the Tone Break feature, for each metal group (Fe, Gold/Non-Fe, Non-Fe) you can change
the point where the low tone changes into the higher tone.
To use the Tone Break feature, first select this setting from the Expert Settings. The names
of the metal groups mentioned above will appear at the bottom of the screen. The Tone
Break point of the metal group will be shown on the screen numerically while the cursor
at the top will point to it on the ID scale. In some modes, there are 2 tone break points and
in some there are 3. To select the metal group, just push the SELECT button. Selection will
be framed. To change the value of the break point, plus (+) or minus (-) button is used.
To give an example for the above explanation; let's say you are in the DI3 mode and you want
to change the Tone Break points. First, select the Tone Break from the Expert Settings. Fe and
Gold/Non-Fe will appear at the bottom of the screen and Fe will be framed. The default value
of 15 will also be displayed on the screen. Using the plus (+) or the minus (-) button change
this number to any value you want. Let's say you increased it to 40. Then, push the SELECT
button once to select the Gold/Non-Fe. Let's say you decreased the default value of 66 to
50. In this case, the device will produce a low iron tone for all metals with IDs equal to or less
than 40, a medium tone for metals with IDs 41-50 and a high tone for metals with IDs greater
than 50 (If you have also adjusted the Audio Tones, the selected frequency will apply to the
new ID ranges).
Tone Break adjustment applies to the selected search mode only. The change does not affect
the other modes.
IMPORTANT!
If you are using the Standard ID scale and you change the operating frequency
of the device, you may need to re-adjust the Tone Break points according to the IDs you will
get in the new frequency.
iSAT (Intelligent Self-Adjusting Threshold)
iSAT in General Search Modes (GEN and GEN (D))
For the General Search Modes (GEN and GEN (D)) to perform accurately, a stable threshold
sound is necessary. You cannot search in the General Search Modes without ground
balancing. Changes that occur in the soil structure and mineralization levels after ground
balancing, may cause a rise or fall in the background hum and disrupt the threshold's
stability which will result in false signals and thus missing signals of small metals. iSAT
adjusts the speed that the device recovers its threshold hum and eliminates the negative
effects of mineralized soils. Increasing the iSAT in high mineralization will enable a more
stable operation by avoiding false signals. This, however, may cause some loss in depth
and it is normal.
NOTE:
In high mineralization, if you receive too many false signals without disruption in the
threshold hum, lower the gain first before increasing the iSAT. If the false signals continue,
set the gain back to its original value and increase the iSAT.
If the mineralization is low, you can decrease the iSAT and sweep the coil more slowly for a
deeper detection.
iSAT consists of 10 levels. The device will start at level 6. It is recommended that iSAT should
be increased in high-mineralization and decreased in low mineralization.
iSAT in Discrimination Modes
It is used to eliminate false signals caused by ground noise or hot rocks when searching in
discrimination modes and the available range is between 00-10. Its factory default value is
set to (1). You can change the value using the plus (+) and minus (-) buttons.
If the device receives a lot of false signals due to highly mineralized soil or hot rocks in the
discrimination modes, first re-ground balance. If the false signals continue, lower the Gain
and check again. In case the false signals still exist, try increasing the Disc.value. Regardless
of all these, if the false signals still exist, first change the Gain and Disc. values back to their
previous levels. Then, increase the iSAT level until the false signals are eliminated.
At the maximum level of iSAT, false signals will disappear or will be minimized. However, in
some cases, increasing the iSAT will result in loss of depth for certain metals such as copper.
NOTE:
When detecting on wet or highly mineralized ground, in order not to miss smaller
high conductive metals (silver, copper etc.) it is recommended not to increase the iSAT level
too high.
NOTE:
iSAT value ranges between 00-10. The factory default is 01. At ''0'', the iSAT feature
will be inactive. If the ground is not highly mineralized or does not contain many hot rocks,
setting the iSAT to ''0'' is recommended.
iSAT in Static Modes
iSAT in static modes is used to eliminate the threshold drifts caused by changes in the
ground and temperature. Threshold drifts will be reflected in the ID scale either in the
positive way (right side) or the negative way (left side).
When the threshold drifts, pull the trigger once to retune the detector first. If the drifts are
substantial and retuning does not improve the situation, increase the iSAT setting in the
Expert Settings to a level where the drifts are eliminated. As the iSAT is increased, the device
may detect weaker signals but will not be able to detect the targets anymore if you hold the
coil stationary or sweep back and forth over the target.
iSAT value ranges between 0-10. The factory default is 3. At ''0'', the iSAT feature will be inac-
tive. If the ground and environmental conditions do not cause any drifts in the threshold,
setting the iSAT to ''0'' is recommended.
Frequency
IMPACT
offers 3 operating frequencies — 5kHz, 14kHz and 20kHz— to suit different target
and soil types.
Based on the frequency selected, the detector's detection performance for different types
of targets will vary. The list below includes, but are not limited to, different types of targets
that correspond to each frequency:
5kHz:
Large ferrous and non-ferrous objects
High conductive coins
Medium or relatively small targets in non-mineralized ground without iron trash
Ferrous masses and militaria
14kHz:
General use
Small coins
Different size coins in medium-highly mineralized ground
20kHz:
Small coins with different conductivities and thin large coins
Gold coins, rings, small jewelry , sheet iron, foil
Small targets in iron trash
To change the operating frequency of the device, access the Expert Settings simply by
pushing the EXPERT Button. After selecting the frequency option, change the frequency
using the plus (+) and minus (-) buttons. You will hear the sound of the relay circuit; this
is normal. At the same time, lines will start rotating in the GB window and they will stop
when the new frequency is active.
EXPERT SETTINGS
