Static All Metal Mode - Fisher F75 SPECIAL EDITION User Manual

F75
LIMITED
Comprehensive Operating Manual & Guide to Metal Detecting

Static All Metal Mode

This mode is useful for finding large, deep objects, i.e. larger than a coin and deeper than 12
inches (30cm). STATIC functions similar to PinPoint but occupies a different position on the
user interface. The audio signal gets stronger as the searchcoil approaches the ground. Unlike
the other modes, the detection sound will not disappear if you stop moving the searchcoil.
The four adjustments are performed the same as with MOTION All Metal Mode, as described
on the preceding page.
THRESHOLD
The audio threshold in the STATIC mode is internally fixed and cannot be adjusted by the user.
Retuning: The audio threshold will slowly drift when searching in this mode. If you move
quickly between temperature environments, such as from shade to sun, audio threshold
may drift more rapidly until the searchcoil temperature stabilizes. When the audio
threshold drifts in this fashion, pull the trigger back momentarily to retune the detector.
You will need to retune periodically when searching in this mode.
AUDIO PITCH
Works the same as in MOTION mode; see previous page.
SENSITIVITY
Set the sensitivity high enough too hear some random background noise and/or a slight
amount of ground response. If you do not hear these noises, you will sacrifice detection depth.
If the background chatter is too annoying, or the ground noise is so high that it impedes
operation, reduce sensitivity. Such a downward adjustment in sensitivity improves depth
detection as you can now hear weak signals better.
The sensitivity system has two stages, 1-29 (low gain), and 30-99 (high gain). As you lower
sensitivity and cross the transition from 30 to 29 in STATIC mode, it may be necessary to
retune by pulling the trigger switch momentarily. You may need to adjust to a setting of 29 or
less to silence electrical interference, or to prevent overload on highly mineralized ground or in
saltwater. You may also notice a shift in the ground balance setting over difficult ground
conditions as you cross this transition.
GROUND BALANCE
Always perform the ground balance procedure before searching in STAT mode, using the
trigger or with the manual adjustment.
If you do not ground balance before searching in STAT mode, most ground will produce an
audible tone as you lower the searchcoil; the ground will "sound off." Some soils will not
sound off, but will remain quiet with a loss of sensitivity.
DEPTH DISPLAY
To see a target's depth, in inches, pull the toggle switch.
TARGET ID
Move coil back-and-forth over target to see visual target ID.
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Comprehensive Operating Manual & Guide to Metal Detecting
Capabilities And Limitations (continued)
STEEL BOTTLE CAPS & FLAT IRON TRASH
Modern motion-type target ID metal detectors usually have difficulty consistently identifying
steel bottle caps and other flat iron trash objects. Double-D searchcoils also have a reputation
for having difficulty distinguishing steel bottle caps from coins, and for being unable to
eliminate steel bottle caps from detection. If you are searching in an area where there are
many steel bottle caps or other flat iron trash targets, minimize the amount of unnecessary
digging with the following methods:
1. SEARCH WITH THE bc (BOTTLE CAP) PROCESS using the PROCESS # feature.
This method calculates visual ID differently in order to cause steel bottle caps to read
lower on the scale, and to register less consistently. A desirable object such as a coin
will usually produce numeric values that are fairly consistent in both directions of
sweep. See PROCESS # under the DISCRIMINATION Mode section of this manual.
2. SEARCH WITH THE dP PROCESS. This method calculates visual ID differently in
order to cause steel bottle caps to ID lower on the scale and to register less
consistently. It also produces more audio clues to the character of the target.
3. LIFT THE SEARCHCOIL. Within 2 inches of a Bi-Axial searchcoil, the crossed magnetic
fields of the Double-D construction can produce anomalous responses. If the object feels
shallow (strong signal, narrow response, or multiple responses in a single sweep) and is
giving consistent high readings like a coin, raise the searchcoil 2 to 3 inches and try again.
A coin will almost always continue to give consistent readings unless it is right next to an
iron object. A steel bottle cap that is at least 3 inches away from the searchcoil will
usually produce readings that bounce around from medium to low numbers.
4. SWEEP THE REAR OF THE SEARCHCOIL OVER THE CENTER OF THE TARGET,
OR SWEEP RAPIDLY.
a. If the ID# is repeatable in the range of 68 to 72, when passing the
center of the searchcoil over the target at a normal speed, then the
target is probably a dime or copper penny.
b. If the ID# is not in the range of 68 to 72 then:
i. Sweep the back end of the searchcoil over the target. If tones
change from high to low, the target is probably a bottle cap.
ii. Sweep the center of the searchcoil rapidly across the target.
1. If tone and ID# drop, it is probably a bottle cap.
2. If a bottle cap, then the faster you sweep, the
lower the tone.
5. USE THE CONFIDENCE INDICATOR
Coins will usually produce a high
confidence level, whereas steel bottle caps
and other trash will usually indicate a low or
erratic confidence, even if the ID numbers
are consistently in the range of a coin.
Confidence level is useful even if not
using the dP or 3b processes.
F75
LIMITED
Sweep back end
of searchcoil over
suspected bottle cap.
(Low Tone = Bottle Cap)
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