Navman 8084, Инструкция по установке и эксплуатации, Страница: 39 / 116

NAVMAN 8120/8084 Installation and Operation Manual 39
A Narrow angle, more detailed 200 kHz cone
B Wide angle, less detailed 50 kHz cone
The 200 kHz frequency generates a higher
definition pulse which produces little shadow
and returns excellent detail over a small
area of bottom. Therefore, it gives excellent
bottom discrimination capability and is
particularly good at showing individual fish,
including bottom dwellers.
When to use 50 kHz
The 50 kHz frequency is particularly suitable
for use in deep water, typically greater than
500 ft (150 m).
At 50 kHz, the cone covers an area of water
about four times wider than the 200 kHz
cone and penetrates to a greater depth with
minimal loss of the return signal.
However, it produces a lower definition
display with more shadow compared to the
200 kHz frequency. This means that a group
of small fish, for example, could be displayed
as a single item, while any fish very close to
the bottom may not be found at all.
This frequency is useful for getting a deep,
wide overview of the area so that any areas of
interest can be identified and then examined
in detail with the 200 kHz frequency.
When to use Mixed
The Mixed frequency combines the 200 kHz
and the 50 kHz echoes on one sonar window,
filling in detailed echoes in the centre of the
sonar cone.
When to use 50/200 kHz
Operating the Instrument at both 50 kHz and
200 kHz simultaneously on a split window
can be very useful when operating in
shallow to medium water, typically less than
500 ft (150 m), because the 50 kHz section
of the window shows the general area,
while the 200 kHz section can be viewed
simultaneously for a more detailed look at
any interesting feature.
To use 50/200 kHz, select the Split 50/200
window (see section 9-4).
A
B