L3 Comminications SERIES 5000 Operation And Maintenance Manual - page 235
D-32
APPENDIX D General Setup, Configuration and Troubleshooting
Series 5000 Sonar System Operations and Maintenance Manual
P/N 11210060, Rev. 13.0
With the function generator and the oscilloscope connected to the cable, monitor
input on the oscilloscope and input a 1 volt peak (2 volt peak-to-peak) sine wave of
the specific frequency of interest. Measure the peak output at the other end of the
cable on the scope through the 50-ohm termination.
Use the formula
dB = 20 log (Vout /Vin)
For example, if at 15 MHz, you get a reading of 160 mv, then
dB = 20 log (0.16/1.0) = 15.9 dB loss.
D.6.3 Spare Tow Cable
Given the nature of high speed towing, cable problems can occur. For
troubleshooting purposes we suggest that you have on hand a lightweight Kevlar
reinforced 150-meter (minimum length) tow cable. This extra cable will allow you
to bypass your primary tow cable assembly and speed up fault isolation.
D.7 Transceiver and Processing Unit
The Transceiver and Processing Unit (TPU) is shown in Figure D-5.
Figure D-5:
The Transceiver and Processing Unit (TPU)