Model TW-8800 Multi Frequency Line Tracer with Hard Case by Fisher Labs

Uses 82 kHz, 8.2 kHz and 820 Hz RF plus digital processing to locate underground lines. Displays depth accurate to 1 inch per foot.


The state-of-the-art TW-8800 utilizes advanced digital signal processing for precision locating performance yet is extremely easy to use. Three active frequencies provided by the transmitter, and two passive modes for tracing without the transmitter, are provided.

The lightweight multi-frequency 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 select the desired operating mode, set the volume level, check the battery level, or activate an LCD backlight. Depth measurement is done at the push of a button.

The transmitter allows the user to locate in either a conductive or inductive mode. A meter and two switches make transmitter set up simple and quick.

In the Fisher tradition, the TW-8800 is affordable, tough, and simple to use while providing maximum performance. A two-year limited warranty comes standard with the unit


  • Advanced digital signal processing for accurate locating
  • Multi-frequency operation
  • Automatic gain control for maximum sensitivity
  • Passive locating modes (power & radio frequencies)
  • Audio and visual left / right guidance
  • Pushbutton depth measurement
  • Large easy to read LCD display
  • Hard or soft carrying case standard equipment
  • Weather resistant design

2-Year Warranty

Fisher warrants the TW-8800 to be free of defects in materials and workmanship when it is shipped from the factory. The terms of this warranty are fully explained in a warranty registration card that accompanies the instrument. Complete factory and field service facilities support the warranty. Warranty may vary outside the U.S. Please see Corrosion Control Products Company for details.


TW-8800 Specifications
  • Depth Accuracy: 
    ±1 inch per foot in nominal conditions
  • Readout Units:
    Inches or cm (factory preset)
  • Left/Right Guidance:
    continuous audio tone = Left
    Pulsed audio tone = Right
    VCO (varying pitch) output for easy over target location. 
    Visual: Left/Right/Over Target messages
  • Signal Strength:
    Digital Numeric Readout (0-99%) & Bar Graph
  • Sensitivity Adjust: Automatic
  • LCD Backlight: Included
  • Battery Test:
    Automatic Low Battery alert
    Push button readout
  • Battery Type: Six "C" cells
  • Battery Life: 80 Hours
  • Weight: 6.0 lbs.
  • Operating Temperature: 
    -4°F to + 140°F (-20°C to +60°C)


  • Output Frequencies:
    82 kHz
    8.2 kHz
    820 Hz
  • Output Power (nominal):
    8l kHz: 0.7 Watts
    8.2 kHz: 7.0 Watts
    8l0 Hz: 7.0 Watts
  • Battery Test: Yes
  • Battery Type: 
    Two 6 Volt lantern batteries
  • Battery Life: 80 Hours at 82 kHz
  • Weight: 7.8 lbs.


  • Headphones - Volume adjusts separately for each ear.
  • Coupling Clamp - Useful for in-service and electrical power line tracing when a metal-to-metal hookup is not possible