Changing The Frequency Of Echoes - NorthStar 6000i Quickstart Manual And Reference Manual

Manually overriding automatic mode
You can always manually change any of
the echo sounder's settings: the gain,
clutter, noise limiter, shift, and range.
(Manually setting the gain causes the range
to be controlled manually.)

Changing the frequency of echoes

The 490 uses two transducer frequencies:
50 kHz and 200 kHz. The advantages and
disadvantages of each frequency are shown
below.
You can choose from four settings for the
transducer frequency:
Reference section 6 — Echo sounding
110

Changing the frequency of echoes

Table 3: 50 kHz vs. 200 kHz
50 kHz
Longer wavelength goes Shorter wavelength pro-
deeper, but with some- vides a sharper picture,
what lower resolution. but can't go as deep.
Less resolution is better at Finer resolution is better at
finding big fish, but may finding small fish (baitfish)
miss the bait fish. and subtle bottom details.
Wider beam is good for Narrower beam is very
seeing fish not directly focused. Reduces the
beneath the boat. influence of a rough sea.
• 50 kHz displayed on a full screen
Changing the appearance of the picture
(colors, gain, clutter, and the noise limiter)
is described in The picture menu, starting
on page 117.
Setting the range and shift is described in
Changing the depth settings, starting on
page 121.
• 200 kHz displayed on a full screen
• 50 kHz on the left half of the screen,
and 200 on the right
• 200 kHz on the left half of the screen,
and 50 on the right
There are two reasons why you might want
200 kHz
to operate with your preferred frequency
on the right side of the screen:
• the zoom function magnifies the
frequency on the right side
• when adjusting the picture, you can see
the effect of changes on the right side
Northstar 6000i