Klein 3000 Series Troubleshooting Manual page 61

SYSTEM 3000 OPERATIONS AND MAINTENANCE MANUAL
TP5 shows the Uplink data. Check here if the towfish is transmitting but there are
data problems.
Each Transmitter board has a TVG (Time Variable Gain) curve that controls the signal
gain.
TP6 shows the TVG for the 500 kHz transmitter board.
L-3 Klein Associates, Inc. TROUBLESHOOTING GUIDE 4-57