Manual

Comprehensive Operating Manual & Guide to Metal Detecting
Comprehensive Operating Manual & Guide to Metal Detecting
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F75
F75
Specifications
Mechanical: S-rod with electronics housing mounted on handgrip, 3-piece
breakdown, batteries under elbow, 2-way armrest adjustment —
forward/backward & around forearm.
Searchcoil: 11” (28 cm) open-frame elliptical double-D, waterproof.
Batteries: 4 AA, alkaline (included).
Weight: 3.5 pounds (1.6 kg) with alkaline batteries installed.
Static Balance: force in vertical plane normal to elbow 0.47 pounds (0.22 kg).Varies
with adjustment and user’s stance and arm/hand physiology.
Dynamic Balance: axial moment, 0.29 foot-pounds (0.39 newton-meters). Varies with
adjustment and user’s stance and arm/hand physiology.
Sweep Effort: lateral moment 5.2 foot-pounds (7.1 newton-meters).
Operating Principle: VLF induction balance
Operating Frequency: nominal 13 kHz, quartz crystal timing reference
Basic Sensitivity: 6 x 10
9
root Hertz (detectivity)
Lag Coefficient: 78 milliseconds
Reactive Overload: approximately 10,000 micro-cgs units (volume susceptibility)
40,000 micro-cgs units with sensitivity < 30.
Resistive Overload: approximately 1,200 micro-cgs units (volume susceptibility)
4,800 micro-cgs units with sensitivity < 30.
Ground Balancing Range: From ferrite to salt, inclusive
Discrimination
Ground Suppression:
combination of second and third order methods
ID Ground Suppression: third order
Battery Life: Typically 40 hours with high quality alkaline batteries
Estimated 80 hours with nickel oxyhydroxide batteries
Estimated 65 hours with lithium iron disulfide batteries
Operating Temp Range: 4 to +122 degrees F (-20 to +50 degrees C)
Operating Humidity Range: 0-90% non-condensing
Cache Hunting
A cache (pronounced "cash") is an accumulation of
money, jewelry, gold, or other valuables, which
someone has hidden. When people bury a cache,
they usually put it in a strongbox or in a jar. To
search for a cache, you first need a reason to believe
the cache may exist. This means doing research.
Some caches have been the subject of many stories
you can read about in print, but you need to be able
to sort fact from fiction. If you can get copies of old
newspaper stories about the circumstances
surrounding the hiding of the cache, you may find
discrepancies which help you to judge the reliability
of the information available. Often the best
information on an old cache is to be learned from old
timers who live in the area where the cache is
thought to be. In the case of newer caches, often the
only information is what can be obtained from family
and acquaintances of the person who is believed to
have hidden the cache.
The ownership of a cache is not always clear.
Sometimes it belongs to the person or heirs of the
person who hid it, sometimes it belongs to the owner
of the property on which it is located, and sometimes
it belongs to the person who finds it -- or some
combination of the above. If the contents of the
cache were stolen, this fact can also complicate the
question of ownership. Find out what laws apply to the cache in question, and always make
sure that the issue of ownership is resolved prior to recovering a cache.
Compared to a coin, a cache is usually large and deep. Searching in Motion All Metal mode is
recommended. However, for a really deep cache, it may be advantageous to search in STAT
mode, frequently pulling the trigger momentarily to maximize sensitivity.
Shallow Water Hunting
All Fisher Research Labs searchcoils are waterproof, allowing you to search in shallow water
about two feet deep. If searching around water, be careful not to get the electronics housing
wet. Avoid salt spray, as it will work its way into the control housing and damage the
electronics -- such damage is not covered by the warranty.
Detecting Activities (continued)
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