Lowrance electronic LMS-320 Marine GPS System User Manual


 
16
Align transducer centerline with hull bottom.
However, there are times when you may need to adjust the transducer
slightly higher or lower. (The slots in the mounting brackets allow you
to loosen the screws and slide the transducer up or down.) If you fre-
quently lose bottom signal lock while running at high speed, the trans-
ducer may be coming out of the water as you cross waves or wakes.
Move the transducer a little lower to help prevent this.
If you cruise or fish around lots of structure and cover, your transducer
may be frequently kicking up from object strikes. If you wish, you may
move the transducer a little higher for more protection.
There are two extremes you should avoid. Never let the edge of the
mounting bracket extend below the bottom of the hull. Never let the
bottom – the face – of the transducer rise above the bottom of the hull.
Shoot-thru-hull vs. Transom Mounting
Typically, shoot-thru-hull installations give excellent high speed opera-
tion and good to excellent depth capability. There is no possibility of
damage from floating objects. It can't be knocked off when docking or
loading on the trailer.
However, the shoot-thru-hull installation does have its drawbacks.
First, some loss of sensitivity does occur, even on the best hulls. This
varies from hull to hull, even from different installations on the same
hull. This is caused by differences in hull lay-up and construction.
Second, the transducer angle cannot be adjusted for the best fish
arches. This can be a problem on some hulls that sit with the bow high
when at rest or at slow trolling speeds. Follow the procedure listed in
the shoot-thru-hull installation section at the end of this lesson to de-
termine if you can satisfactorily shoot through the hull.
TRANSOM TRANSDUCER ASSEMBLY AND MOUNTING
The best way to install these transducers is to loosely assemble all of the
parts first, place the transducer's bracket against the transom and see if
you can move the transducer so that it's parallel with the ground.
Transom
Hull bottom
Transducer
centerline