19
TOW CABLE
The 150' to 500' tow cable is a hollow core polypropylene rope with three electrical cables in the center. One cable is a
six conductor cable which is used for sending the transmit pulse and voltages to the fish. The other two cables are coax's
which are used to send the return echoes, from the preamps in the fish, to the left and right channel TVG circuits in the
Sonar Processor.
The returning echoes strike the transducer which produce the return electrical signals. The signals are amplified by the
preamp and sent up the tow cable to be processed by the "time variable gain" (TVG) circuit in the Sonar Processor.
Signals continue to be received and amplified until the next transmit pulse. The sequence is then repeated.
A
m
p
l
i
t
u
d
e
#1
#2
Transmit pulse
8"
Next transmit pulse
Shadow
Shadow
Signal to Sonar Processor
Wires To Surface Control Box
Transmit
Circuitry
Pre-Amp
Transmit Pulse
From control box
Signals To
Control Box
Transducer
Sonar Processor
Sonar Processor
Sonar Processor
FISH ELECTRONICS
The fish contains a underwater housing that contains the electronics to generate the 1000 watt power pulse to each
transducer; and preamps to amplify the returning echoes received by the transducers. The amplified signals are then
sent to the surface Sonar Processor where they are processed.
10m
#1
#2
100 m Range Switch
Returning Echos
Fish
Acoustic
Wave
100 m
Hard Return
No Return Echos (Shadow)
Light Return
Medium Return
Hard Return
The transmit pulse is generated by the Computer. The signal is sent down the tow cable where it triggers the
transmit circuitry in the fish. The transmit circuitry generates the 1000 watt power pulse to each transducer. The
transducer generates the narrow sound beam that travels out away from the side of the fish. Echoes immediately
begin returning from the bottom as the wave continuous to sweep across the bottom.
Содержание SSS-100K PC
Страница 51: ...51 Left Blank ...
Страница 55: ...55 Left Blank ...