7
ACCESSORIES
The coupling clamp is useful when the utility is exposed,
and a direct connection is not possible. It is plugged into
the same plug-in socket as the ground-plate/ground-rod
assembly. The coupling clamp only operates at the 82 kHz
frequency. The coupling clamp will fit around utilities that
are 3-¼ inches in diameter or smaller. The length of the
cable is approximately 10 feet.
Coupling Clamp
Fisher Research Laboratory has a variety of headsets avail-
able.
•Ultra-quiet deluxe Fisher Phones. High quality sound
while reducing the outside noise.
•Standard Stereo Headphones
•Single Earpiece Headset. Enables the operator to effec-
tively listen to the TW-7700 and remain aware of noise in
close proximity.
Headsets
This represents a jumper
Coupling Clamp Applications Diagram
A. The coupling clamp is for all
tracing applications with conduc-
tors exposed; exception, an open
circuit at line’s termination.
B. A ground must be provided
for the proper current flow when
the coupling clamp is used at a
termination.
C. The coupling clamp must be
used between the grounding
and where the line goes under-
ground.
D. Trace signal will return to ground
when incorrectly coupled.
E. Signal will be transmitted in both
directions when connecting is
midway in a long conductor.
F. Drop lines or laterals divide the
signal strength in half at each
junction.
