Furuno CH-300 - Manual (Page 20)

1. OPERATIONAL OVERVIEW
1-10
Frequency selection and mode
Single-frequency display or combination display (other than vertical scan
combination):
The LF/HF key chooses low frequency or high frequency alternately.
Dual-frequency display (mix mode OFF):
The LF/HF key switches the frequency of the
high-and low-frequency displays alternately.
Dual-frequency display (mix mode ON):
The LF/HF key changes the frequency of the
left-hand display* (top display in dual-frequency vertical scan display) from low to high
alternately.
* Dual-frequency horizontal display, Dual-frequency horizontal expansion display,
Dual-frequency echo sounder display.
LF/HF key MIX
DISPLAY
HIGH-FREQ.
DISPLAY
MIX
DISPLAY
LOW-FREQ.
DISPLAY
Frequency switching in dual-frequency combination display, mix display ON
Combination display (vertical scan combination):
Main window is active: The LF/HF key changes the frequency of the main window from low
to high alternately.
Sub window is active: The LF/HF key changes the frequency of the sub window from low to
high alternately.
To switch between main and sub windows use the MAIN/SUB key.