NorthStar EXPLORER 457 Installation And Operation Manual page 20

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 display, filling
in detailed echoes in the center of the sonar cone.
When to use 50/200 kHz
Operating the 457/467 at both 50 kHz and
200 kHz simultaneously on a split display 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 display 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 display
(see section 4-4).
20 Northstar FISH 457/467 Installation and Operation Manual
B
A Narrow angle, more detailed 200 kHz cone
B Wide angle, less detailed 50 kHz cone
A
B