Instruction manual
CABLING
INSTRVM ENT/INDICATOR
I CAUTION I
Do
not
lX'int
the
tranJduoc:r l'aoe.
FORWARD·LOOKlNG
ALARM
Thc
micropf'OCUIO
••
utom.tit.lIy
compuus the slope trend of the s
..
bott.om
whilc thc
vusel
is
underw.y. The forward lookinlJ
.I.rm
lutom.tie-lly
sounds when the MKl72 system senses the
proximity
of sho.linl( conditions Ipprosim.tely
20
lecondl before the Yellel would rcach the shoal
(run
aliTound).
The forward·lookinl(
Il.rm
function
is
b
...
d
on
I computation of I liT.dually rising bottom. the
audible
annundator
produces I 1I2'lecond beep
rau
until
one
of the three amditionl
il
met:
1.
A
fiud
depth is m.intained
2.
Boat moves into deePlir
w.ter
3.
ALARM
pushbutton
II
momantarily
deprused
to acknowledge
.larm
condition.
SAlLING
WITH
THE MK172 DEPTHSOUNDER SYSTEM
Thc
MK172
~pthsoW1der
S,.tem
provides computeriud alarm senling tha.t
loob
down
.nd
forward. The
uHr
selects
.nd
leta tha
.llrm
depth. The depthlounder monitors the changinll' bottom
conditions
.he.d
of the
bo.t
.nd
sutomaticilly so\llldl 2.
.5
to
20 leconds prior
to
rcaching tha.t depth,
If the boat
illlilinll'
in.n
Irel
wh.r.
the bottom
il
.ela.tively smooth and
i.
Meominll'
aha.llower
a.t
a
slow
rate, a sma.llnfety margin (shillow
.I.rm
depth) can be
lit
into the system. Ifthe bottom could
rise very quickly
or
hu
llrg.
rockl. I
duper
a.larm
depth Ihould be set
so
lU
to
give adequate
wa.rninll'
time. The pT\ldent IIllor should allow
for
tha depth of the troughs between the waves as
well
as the time
in
the tide cytle,
The
fo
d looking a.llrm does not
.nu.lly
look
fo
......rd,
but
clleul.tu
the rate
at
which the water
is
getting
l1ower
Ind
detennin
..
wh.n tha
w.te.
will
be
shallower than the
set
depth
.l.nn
baaed
upon
time.
In
effeet, the forward-lookinlJ
Il.rm
tona tells
thl
crew, 'Wlter is deep enough
now,
but
at
the rate depth
is
deere.linl(, tha
watt.
depth
will
bile
..
than lJlI set a.lann deplJl in 20 seconds". The
forward looking
alann
wlml
the
a.ilo.
thlt
the bottom is rilinl( and provides
II
re3.JIonable
amOWlt
of time
for
chaniing
courH.
Although the forward lookinlJ
allnn
provides lome addition.1
I.fety
mcasures \IIlder most
conditions. the aailor mUlt
be
IW.TII
of
whit
it Clnnot
do.
It Clnnot predict a rock six feet high
immersed
in 10 feet of water
.nd
diT1letly
in front of the bolt,
It
cannot predict the vertic.1 or
nur
vertical edge
of.
chann.lthrough which the boat il pUlinlJ, or
th.t
20
f",t
ofwater depth beeomu
only
three fcet
ofw.u.r
depth
in
one
boat langth.
So
while both down-looklnlJ
.nd
fO
lrd·.I.rml
can be very useful, they Ihould not be relied
on
as
the only
way
to
avoid Ih.l1ow
w.te
....
lD
,.
.
IV.
PREVENTATIVE MAINTENANCE
PTllventatlva
m.inten.nct
il
care and c1nninl(. The
MK172
Iylt,m
contalnl two
di5Crete
m.jor
componentl: tranlducer with attached inter<:onneet cabll
.•
nd InltT\lmenllindicltor.
TRANSDUCER
For proper Iystem operation. the transducer mUlt
be
completely "wetted" before
Ule,
WettinlJ
.equir
..
from
24
to
48
hours of continuous imme
..
ion
in
Wlte
•.
COltins tha lenlOr f.ce
ofth.
tr.nsducer
with liquid detergent before launchins can shorten tha
.....
ttinll time.
Clell'linl( the
tunsducer
should
be.
periodic function.
Loc.1
uparience
with bottom
foulinlJ
can
halp the
Ullr
d.tennin.
the frequency of cleaninl(.
To
cllln
the tr.nsdllCe.,
lCT\lb
the
MnlOr
face
.nd
thl
.rea
Iround the thru.hull fitting with I
3M
SCT\lb
Pld or 800
rrit
""at-dry
undpaper.
If
cleaning
il
done in • dry environment (transducer removed
0.
boal out of w.u.r), ""ettinlltim,
must
be
.llowed
for
'«UTlte
indicationl
to
be obtained. Other
th.n
oct,lionll
cl,.ninlJ, the
trlnsduce
••
eqwTIII
no
rel(\llir
mlintenlnce.
If the
LCD
luddenly indicates
uro,
becomn err.tie,
or
Ccnlilu.ntly
prellnta
• depth indic.tion lower
than
known charted depth,
the
problem
il
usull1y in
t.he
c.bln
or in
thl
trll'lsducer Ioc.tion. Check
power
Ind
trll'lsducer cable connections first: they ahould be tighL Inlpeet physic.1
eonditicll'I
of
clbl,
..
If they
.re
.ged
Ind
insulation
il
""om
or d.maged.
thly
should be rlpl.cad. If tha use. has
10m. meanl of checking the continuity ofcable wirinr:
e.IJ,
••
nd Ohmmeter,
th.
c.bl
..
should
be
10
checked while
nuing
the
c.bln
It
interv.ls alonll
tM
tntire
length. Tha cabl.
Ire.
immedi.tely
nut
to
the conneeton
may
be
especi.lly
V11lnerabl.,
Cabin
with brokln or short·dreuitad
wirn
mUlt
be
replaced.
Cable routinlJ Ihould also be cheeked.
Look
for
wear
pl.cn
that
could
dlm.p
inlul.tion, and
look
for c.bla proKimity to other electrical equipment
th.t
could .llow pickup of eleClric.1
intenennce
noile. Sourc
..
of noise generation could
be
engine ignItion, radio tranlmitter, or other on.board
eleetrie.1
appar.tul.
If
wear
Or
abrasion points
Ira
in
cable
pith,
reroute cabla.
If
lourcn
of
elactric.1
noill
reneration are
in
cable path, reroute cabl., or
lnitallin
electricil
noill
lupprusor
In
the cable line.
The
inllr1,lllllntlindieator is I solid·steu. eleet.onics
I"ambly
with
no
movinlJ
p.rtl.
It
is desian
ed
to
be virtUll1y maintenance free. When not in use, ita front
panilihouid
be
conrad
with
th.
Protective
Cov,r
(Sipet
PIN
M0212.otl. Periodically check
th.
cabl,
conn,etionlll'ld
el
••
n the f
••
e
of the dilplly.
II