Fisher TW-7700 Line Tracer from GISCO

The state-of- the-art TW-7700 utilizes advanced digital signal pro-cessing for precision locating performance yet is extremely easy to use.
The lightweight receiver is simple to use. The display is a large and easy to read LCD that gives the user all the necessary information to do the job. A digital keypad allows the user to set the volume level, check the battery level, or activate an LCD backlight. Depth measure-ment is done at the push of a button.
The transmitter allows the user to locate in either a conductive or inductive mode.Ameterand switch make transmitter setup simple and quick.
In the Fisher tradition, the TW-7700 is affordable, tough, and simple to use while providing maximum performance. A two year limited warranty comes standard with the unit.

A coupling clamp accessory can be used with the transmitter when a direct physical hook-up cannot be done with insulated pipes, and electrical or telephone lines that are in service.

INDUCTIVE TRACING:
When one point is known on a linear conductor, such as a pipe or cable, the TW-7700 transmitter can be placed on the ground over it, and tracing can go in either direction from that point. The operator walks the path of the line while moving the receiver left and right. At some.distance from the transmitter, the signal will become faint, but thetransmittercan be brought upto that point so tracing can continue indefinitely. Note: If there is no known starting point to do an inductive or conductive trace, use a Fisher TW-6 with handle to inductively locate a starting point.
CONDUCTIVE TRACING:
This is the preferred method for tracing because the transmitter makes a direct physical hook-up with the line to be traced. The included ground-plate/ground-rod assembly plugs into the transmitter, and one alligator clamp is attached to the pipe, non-energized cable, conduit, tracer wire or tracer tape. The other end must be well grounded. This concentrates the signal on the known line to be traced, and there is less chance of the signal being accidentally induced to a nearby or adjacent line. Tracing distances are usually increased 25-50 percent over the induc- tive method. Non-metallic pipes may be traced conductively if the ground-plate/ground-rod assembly is attached to a plumb- er's "snake" or electrician's "fishtape" running inside of the pipe.
INDUCTIVE COUPLING CLAMP:
The coupling clamp takes the place of the ground-plate/ground-rod assembly when tracing telephone and electrical lines that are in service. It inductively energizes without metal-to-metal contact. Tracing distances are less than when using the ground-plate/ ground-rod assembly, so there is no advantage to using the coupling clamp on pipes unless a non-conductive wrapping or insulation is preventing direct metal contact. The TW-770 frequency will not disturb voice, data-communication lines, or electrical service when the coupling clamp is used.