DESCRIPTION
4
The passive locating method utilizes only the receiver.
This method of locating uses signals that are inher-
ently associated with the utility. The TW-8800 has two
modes for passive locating: 50Hz/60Hz (power) and
14 kHz to 30 kHz (radio). The power mode senses the
electromagnetic fields on energized electrical lines.
The radio mode senses the re-radiated radio waves
that are occasionally associated with utilities. Often
these signals are weak, so to assist the operator, we
added a feature that oscillates the signal, thus al-
lowing the signal to be heard.
The features of the TW-8800 make it a very versatile
and practical instrument in today’s world of under-
ground locating.
SPECIFICATIONS
Subject to improvement or modification without notice.
13
Depth Accuracy ..................... +1 inch per foot in nominal conditions
Readout Units .......................... Inches or cm (factory preset)
Left/Right Guidance ............... Audio: continuous tone=Left,
pulsed 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 Temp ...................... -4
0
to +140
0
F (-20
0
to +60
0
C)
Output Frequencies ................ 82kHz, 8.2kHz, 820Hz
Output Power (nominal) ........ 82kHz: .7Watts, 8.2kHz: 7.0Watts
820Hz: 7.0Watts
Battery Test ............................... Yes
Battery Type ............................. Two 6 Volt lantern batteries
Battery Life ............................... 80 Hours at 82kHz
Weight ...................................... 7.8 lbs.
TRANSMITTER
RECEIVER
Fisher Research Laboratory does not warrant suitability to specific use. Fisher Research
Laboratory shall in no event be liable for any direct, incidental, consequential or indirect
damages.
