10
SEARCHING
7. You are ready to search when the BALANCE knob 
is  adjusted within the  1/8- to  1/4-turn  silence (null) 
space. This is extremely important! If this procedure 
is  not  followed  correctly,  the  GEMINI-3  will  either 
constantly  give  false  audio  and  meter  readings 
(sensitivity  too  high), or  no  signals  at  all  (sensitivity 
too low). The sensitivity will be correctly set and your 
GEMINI-3 will operate properly only when a 1/4- to 
1/8-turn null has been achieved. If you lower or raise 
your GEMINI-3, you may have to retune by making 
repeated adjustments to the BALANCE knob and/or 
the SENSITIVITY control.
Operating
1. Test your GEMINI-3 in an area you are reasonably sure 
is free of large buried objects.  Scatter some metal 
objects, such as a tool box, piece of pipe.
2. With the instrument properly tuned and held in the 
hand or suspended by the strap, slowly walk directly 
toward your test  object. Keep  the handle as  level 
and steady as possible while in motion or the tuning 
may change and you’ll receive false signals and/or 
lose sensitivity. 
3.  As  you  approach  your  target,  the  speaker  sound 
and meter  indication  will  increase.  They will reach 
maximum readings when you are directly over the 
conductor  (target).  Remember,  on  the  GEMINI-3; 
unlike earlier models, the sound volume  and  pitch 
continue to increase after the meter pegs. This allows 
you to  pinpoint without constantly  readjusting  the 
SENSITIVITY knob. 
4. As you cross the target, the signal indications will begin 
to decrease because you are moving away. To get a 
precise fix on the location, make a mark at your feet 
when readings reach their maximum. Cross over the 
target, turn around and come back. Make a second 
mark when readings return to maximum. Your target 
will be centered between the two marks. 
15
TRACING
 
        Operating
1. 
Once the two starting points have been established 
and the receiver tuned, walk away from the transmitter 
in the assumed direction of the buried conductor. 
2.  Hold the receiver vertically to maintain a peak signal 
or horizontally, face up, to maintain a null or minimum 
signal. Either method indicates that you are over the 
object and tracing its path. 
3. As  the distance from the transmitter  increases,  the 
signal will fade. As this occurs, increase the SENSITIVITY 
as required.
4.  When the signal becomes too weak to trace, stop 
and move the transmitter closer. 
5.  Be aware that if you are tracing a pipe, each time a 
“T” junction or lateral is encountered; the signal will 
split and weaken. 
Conductive Trace
    This is the best method for tracing a single pipe in the 
presence of other pipes. A portion of the pipe must be 
exposed in order to energize it by direct connection 
utilizing a Ground Rod Assembly (not included).
        Set Up
1.  If possible, clean the contact point of the pipe with 
a wire brush. 
2. 
Connect the ground plate clamp to the contact point.
 
3.  Plug  a  Ground  Rod  Assembly  into  the  transmitter 
Ground Plate Jack. 
4.  Set the transmitter on the ground and in an upright 
position  as  far  away  from  the  contact  point  as 
possible, at right angles to the assumed direction of 
the pipe or cable. Insert a Ground Rod Assembly in the 
ground as far away from the transmitter as possible. 
5.  Hold the receiver vertically, in line with the contact 
point of the pipe at least 30 feet away.