9
1. Set as in the “Turn-On” procedure, making sure the 
DISC  control    is  at  AUTOTUNE  and  the  SENSITIVITY 
control is set so you can just barely hear a threshold 
hum.  Hold  the  search  coil  parallel  to  and  6  to  12 
inches over the ground and at least three feet away 
from any metal objects. Do not use the PINPOINT 
button during any part of this procedure.
2.  Lower the coil to an inch or two above the ground 
and then quickly raise it. Note that as you lower the 
coil, the tone disappears, then gets louder as you 
raise it and finally returns to normal when you stop it 
6 to 12 inches above the ground. Conversely, if you 
set the GROUND control to 1, the threshold hum will 
get louder as you lower the coil and disappear when 
you raise it.
3. Your objective now is to adjust the GROUND control 
so  that  there  is  no  change,  or  only  a  minimum 
change in the threshold hum, as you move the coil 
up and down. Start by lowering the GROUND control 
to 9. Lower the coil and raise it again. One of three 
things will happen to your theshold hum:
A It will fade again as you lower the coil and increase 
as  you  raise  it.  Continue  to  lower  the  ground 
balance  setting  in  small  increments  until  the 
threshold hum remains the same (or changes very 
little) as the coil is lowered and raised.
B    It will get louder as you lower the coil and go silent 
as you raise it. Increase the ground balance level 
(rotating  the  control  counterclockwise)  in  small 
increments until there is little or no change in the 
threshold level.
C    The  hum  will  remain  the  same,  or  if  it  changes 
slightly, the change is the same whether you lower 
or  raise  the  coil.  Your  CZ-3D  is  properly  ground 
balanced,  and  you  are  ready  to  begin  your 
search. You have gone past the correct ground 
balance setting. 
4.  With a little practice, you should be able to ground 
balance  quickly  by  “bobbing”  the  coil  up  and 
down in a continuous movement as you adjust the 
GROUND control with your thumb.
"BOBBING" THE SEARCH COIL METHOD