wheels by reversing the proce-
dure used to remove the old
one. BE SURE the fingers of
the new stylus are pointed UP.
6. Close the front of the case.
Latch both catches at the top
of the unit.
MAINTENANCE
NOTE: The stylus may be
damaged if it is in front of the pla-
ten when the platen assembly is
pulled down. Always
move the
stylus
to the back side of the pla-
ten when changing the
paper
rolls. Remember to move the belt
down to remove the stylus.
Black carbon dust is created dur-
ing the
recording process. Use a
soft, oil-free
rag to clean the
viewing door and metal platen be-
hind the paper. Low pressure
compressed air may
be used to
blow dust out of the case and
away
from moving parts if the air
is dry and free of oil.
All mechanical connections
should
be checked periodically to
be sure they haven't worked
loose.
HIGH VOLTAGE is present in the
transmitter section when the unit
is ON. No attempt
should be
made by any unauthorized per-
son to modify
or repair
the elec-
tronic
section.
All electrical connections should
be checked periodically and
cleaned as necessary.
The face of the transducer, if
mounted on the transom should
be washed periodically with mild
soapy
water to remove
any ac-
cumulated rod grime or oily film.
This is essential to have good
contact between the transducer
and the water.
DO SECTION
Do carry a spare fuse, stylus belt,
and roll of paper.
Do use the empty
cardboard core
from the last roll of paper
on the
take-up post.
Do keep the recorded graphs
for
future reference.
-Do clean the stylus belt, wheels,
and the rubber roller after every
five rolls of paper.
DON'T SECTION
DON'T OPEN THE CASE WHEN
THE UNIT IS ON.
Don't
pull the platen assembly
down when the stylus is at the
front.
Don't store any objects
inside the
F case or behind the viewing win-
dow. (Except for small pieces of
tape.)
Don't
forget to tape the
papeito
the take-up
core.
Don't rotate the stylus
belt up.
Don't use oily cloths, strong sol-
vents, or abrasive cleansers.
TROUBLESHOOTING SECTION
Symptom
On/Off switch Is "ON", but the
stylus
and paper
don't move.
What To Do
Check fuse; check connections at
battery for
tightness
and
corrosion.
Symptom
On/Off switch is "ON", have zero
mark, but no echoes or bottom
signal.
What To Do
Be sure the transducer is plugged
When high Sensitivity settings
are used, a second bottom echo
will appear. This is normal and is
caused by the returning signal re-
flecting
off the surface of the
water, making a second
trip to the
bottom and back.
If detailed information about
brush piles, individual fish, or the
thermocline is desired,
the Sen-
sitivity knob should be rotatedto
approximately the 3/4 point. Refer
to the illustration
below to see
ft -'
,7't I
—
SENSITIVITY: TOO LOW
U
what effect
the Sensitivity
control
setting has on the recorded
information.
Recording individual fish with an
"arched"
signature
can usually be
accomplished at
trolling speed
with the
Sensitivity
knob at the ¾
point, or higher. Refer to the §ec-
tion "Arched Signatures" for more
information about this important
function of your recorder.
Suppression Control
The Suppression Control is
used to reduce interference from
noise. Noise, in electronic
terms,
is any undesired signal. It can be
caused
by an electrical source,
(such as the engine's ignition sys-
tem) or by air bubbles in disturbed
water which is call cavitation. In
both cases, the noise could pro-
duce uhwanted marks
on the
paper. (See Figures 7 &
8.) Fortunately, noise pulses are rela-
tively short in time compared to
real sonar signals.
Advancing the
Suppression knob will cause the
system
to reject these unwanted,
short pulses without
reducing
the
2
Figure 4
Figure 5
SENSITIVITY: PROPER SETrING
16 5
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