Basic Theory Of Operation - Fisher Gemini-3 Operating Manual

BASIC THEORY OF OPERATION

The GEMINI-3 was engineered to detect conductivity
changes in the earth over which it is carried. Hence, a positive
response by the GEMINI-3 indicates the presence of a metal
object, ore vein or mineral that is more conductive than the
surrounding rock or soil.
The function of the GEMINI-3 Transmitter is to send a radio
frequency (RF) signal down to a conductive object and
generate an electromagnetic field around that object.
When used in any of the Inductive modes, the RF signal
travels through the ground to the object. When used in
the Conductive Trace mode (see page 15), the signal is
transmitted directly through a wire attached to an exposed
portion of the object.
The function of the GEMINI-3 Receiver is to locate the
object by detecting the electromagnetic field around it and
responding with audio and visual signals.
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Where To Use Your Metal Detector In The U.S.
National Forest and Federal Lands—Metal detecting is allowed
only by special permit acquired from the federal government.
Each area has a district office.
Corps of Engineers, Lakes, Shorelines and Lands—Permission has
been granted only on pre-disturbed sites, such as beaches and
attached swimming areas. New Corps lakes and lands must be
okayed by the main office of the Army Corps of Engineers. Each
area has a district office.
State Parks and Lands—Some state parks are open to metal
detecting, but some are not. Always check with the park ranger
before attempting to use your detector.
Bureau of Land Management (BLM) Lands—Some areas are
open for metal detecting, and some are not. Always check with
the district office.
City or County Park Lands—Most are open to metal detecting
unless notice is given by a sign or city ordinance. When in doubt,
always check with the city's Parks and Recreation Department.
Public School Grounds—Most are open to metal detecting unless
notice is given by a sign, city ordinance, law enforcement official,
or school employee. You should always check with the school
office first.
Privately Owned Lands (Private Property)—Permission required. It
is always best to have the permission in writing.
Historically Marked Lands or Sites—Metal detecting is not
allowed. Don't even think about it.
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