Insignia 105SX - Manual (Page 8)

USING THE 105SX
HOW SONAR WORKS
6
HOW SONAR WORKS
Your Humminbird unit uses sonar to
locate and define underwater
objects, define the bottom terrain, as
well as determine distance.
Sonar technology is based on sound
waves. Your Humminbird unit sends
out a sound wave signal. With this
signal it determines distance by
measuring the time between the
transmission of the sound wave and
when the sound wave is reflected off
an object. Your Humminbird uses the
reflected signal to interpret location,
size and composition of an object.
Sonar is very fast. A sound wave can travel from the surface to a depth
of 600' (185m) and back again in less than
1 /
4
of a second. It is unlikely
that your boat can "outrun" this sonar signal.
The 105SX is a 200kHz, single-beam fishfinder. The 200 kHz frequency
provides excellent sonar resolution (the ability to distinguish small
returns or returns which are close to the bottom), while providing depth
capabilities to 600’ (185m). The shape of the sonar beam is symmetrical
and covers an area of approximately 24 degrees side to side and front to rear.
Actual depth capability depends on factors such as bottom hardness,
water conditions, and transducer installation. Units will typically read to
deeper depths in fresh water than in salt water