To select the transducer that's best suited for your needs, you
need to consider the transducer's operating frequency, cone angle and type of
Most of the sonar units that we sell
accessories for operate at 50, 83,192 or 200 kHz (kilohertz). A few are dual
frequency capable, meaning they can use both 50 and 200 kHz transducers.
Typically, high frequency (192 or 200 kHz) sonar units provide the best
resolution and definition of structure and targets. They excel at showing
minute details of the underwater world (at depths up to 800 feet). 50
kHz units have much greater depth penetration capability, but show less
definition. 50 kHz transducers also usually have a much wider cone angle than
192 or 200 kHz transducers.
» You must match the transducer's
frequency to the sonar unit. For example, a 200 kHz sonar unit requires a 200
A transducer's cone angle determines
its coverage area of the underwater world. The wider the cone angle, the
greater the area that's covered. We offer a variety of 192 kHz transducers with
either a wide (20°) or narrow (8°) cone angle. We also offer a variety of 200
kHz transducers with either a wide (20°) or narrow (12°) cone angle. The 50 kHz
transducers come with a 35° cone angle. And the dual frequency transducers come
with both a narrow (12°) 200 kHz and a 50 kHz cone angles.
» Generally, use a wide cone angle for fishing shallow to
medium depths. The narrow cone penetrates to deeper depths, but shows less fish
and structure due to its narrow beam.
The depth capability of your sonar
units depends on its transmitter power, receiver, sensitivity, frequency, and
transducer installation. Other things that effect depth capability are: water
conditions and type, (all sonars will show deeper depth readings in fresh water
than salt) and bottom conditions.
Types of Transducer Installation
Most of our permanent-mount
transducers are designed for high-speed operations. For the best results, the
transducer should be placed where a smooth, undisturbed flow of water will pass
across the face of the transducer at all boat speeds.
Read your transducer's
owner's manual before installing the transducer!
The transom-mount transducer is the most popular, and it's
generally the easiest to install. The Skimmer® transducer design performs best
when it is slightly below the boat's hull. A plastic transducer is recommended
on aluminum or steel-hulled boats to avoid potential electrolysis problems.
Mounting the transducer on the transom is recommended for outboard and
stern-drive (I/O) powered boats only. Transom mounting is ideal for high-speed
operation and models with the "kick-up" feature will prevent damage
if the transducer strikes an object.
Make certain that the chosen location doesn't interfere with the boat's
trailer. DO NOT mount the transducer directly behind the ribs, or thru-hull
fittings. Typically, on aluminum boats, mounting the transducer between two
ribs works best. On all hulls, mount the transducer at least one foot away from
the engine's lower unit. This helps to prevent air bubbles from the transducer
interfering with the propeller.
» Periodically wash the bottom of
the transducer with soap and water to remove any oil film or growth that may
collect. Oil and dirt reduce the transducer's sensitivity and can even prevent
In this installation, the transducer is bonded to the inside
of the hull with epoxy. Ideally, the transducer is placed in the aft third of
the hull close to the centerline. The signal "shoots through" the
hull with some loss of signal strength. This installation must be made in an area
of the hull that is made from solid fiberglass, with no air bubbles or
separated layers. If the hull is of multi-layer or "sandwich"
construction, you will have to remove the inner layer of fiberglass and the
wood or foam core to expose the outer layer of the hull. This type of mount is
recommended only with 192 or 200 kHz transducers.
In this type of installation, a hole is cut in the hull and
the transducer is mounted through the hull by means of a threaded shaft and
nut. If the boat hull has a dead rise higher than 10 degrees, fairing blocks
made from wood or plastic must be fabricated so that the transducer will mount
in a completely vertical position. The TH-FLW P5 model does not require a
On in-boards, the transducer must be installed ahead of the propeller,
shaft(s), and engine water intake(s).
» If the boat's hull is made of steel or
aluminum, use a plastic transducer to prevent electrolysis problems.
Trolling Motor Mount
The PD-W "pod" transducer is designed for mounting
on an electric trolling motor. It has two slots for a hose clamp (which must be
purchased separately). Skimmer® transducers can also be mounted on a trolling
motor using the TMB-S trolling motor bracket. It's curved to fit the contour of
most electric trolling motors.
Most of the sonar units that Tech & Tackle sell are accessories
for operate at 200 kHz (kilohertz). Some are dual-frequency capable, meaning
they can use both 50 and 200 kHz transducers. And a few new models are
dual-search capable, allowing for both 83 and 200 kHz operation. Typically,
high frequency (200 or 192 kHz) sonar units provide the best resolution and
definition of structure and targets. They excel at showing minute details of
the underwater world. 50 and 83 kHz frequencies have much greater depth
penetration capability, (for deeper body's of water) but show less definition.
You must match the transducer's frequency to the sonar unit. For example, a 200
kHz sonar unit requires a 200 kHz transducer.