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TOW LINE - The 150' (300'/500'/1000' options are available) Tow Line consists of a multi-paired cable and
coax which is the core of a braided polypropylene line. The combination results in a highly
abration-resistant tow line. One end of the Tow Line is wired into the Fish, and the other end plugs
into the Control Box. The Tow Line is marked (black tape) every 50' to aid you in determining how
much line is out (see chart below).
FROM FISH END
BANDS FOR 300'
BANDS FOR 500'/1000'
50' ................................... One band
100' ................................... Two band ............................. One band
150' ................................... Three bands
200' ................................... Four bands ........................... two bands
250' ................................... Five bands
300' .................................................................................. Three bands
400' .................................................................................. Four bands
500' .................................................................................. Five bands
600' .................................................................................. Six bands
700' .................................................................................. Seven bands
800' .................................................................................. Eight bands
900' .................................................................................. Nine bands
To avoid any damage to the cables, do not tie the Tow Line in a knot or make any sharp bends
with it (do not tie it off on a cleat).
CONTROL BOX - The Control Box receives the signal (pulses) from the Fish, filters the signal, and counts
the pulses. After the pulses are counted, it stores the results and displays the count on the five
digit LCD readout. The Control Box contains a single main logic board.
MAIN LOGIC BOARD (MLB)
The MLB is divided into three sections; analog, digital, and power supply.
The analog section receives pulses from the tow fish, filters and amplifies them, digitizes
them and sends them to the digital section for processing.
The digital section computes the gamma count and sends it to the readout board. The digital
section contains the micro processor and memory circuits which control the overall timing
of the system. The digital section also controls the optional printer, Loran C/GPS input, and
RS232 computer interface.
The power supply section provides the proper voltages for the entire system.
P 4 CO NT RO L B O X
R E A D O U T
P U LS E S
F R O M
F IS H
A N A L O G
D I G I TA L
P R IN TE R
F ILT E R S
AT D
P S
M E M O R Y
M IC R O P R O C E S S O R
T IM IN G
M LB
