Raymarine a67, Инструкция по установке и эксплуатации, Страница: 191 / 330

Frequency adjustment (CHIRP sonar module
in non-CHIRP mode)
When using a CHIRP sonar module in CHIRP mode (Low Chirp,
Med Chirp or High Chirp) the frequency cannot be adjusted.
When using a CHIRP sonar module in a non-Chirp mode (e.g.
50 kHz or 160 kHz) the frequency at which the transducer is
transmitting can be adjusted.
With the CHIRP sonar module set to a CHIRP mode (e.g. Low
Chirp or High Chirp) the CHIRP sonar module will sweep the
transducer’s available frequency range in each ping.
With the CHIRP sonar module set to a non-CHIRP mode
(e.g. 50 kHz or 160 kHz) the CHIRP sonar module can adjust
the frequency at which the transducer is transmitting. The
advantages of being able to adjust the transmit frequency
include:
• Optimization for particular species of fish and water conditions.
• Avoiding interference from other sonar operating nearby (at
the same frequency).
• Use of wide or narrow beam on a particular transducer.
The graph below depicts the adjustment (selection of a specific)
frequency when using a CHIRP sonar set to 160 kHz.
CHIRP sonar module frequency
1 20 130 140 150 160 170 180 190 200 210 220
S
e
n
s
it
iv
it
y
(
d
B
)
Fre q u e n c y
-50% +50%
1
2
3
D12575-1
1. Frequency adjustment range.
2. Transducer characteristics.
3. Operating (center) frequency.
Adjusting the fishfinder frequency (CHIRP sonar module
in non-CHIRP mode)
When connected to a CHIRP sonar module set to a non-CHIRP
mode you can manually adjust the transmit frequency.
From the fishfinder application:
1. select
Menu .
2. Select Frequency settings .
3. Select either Tune Freq 1 or Tune Freq 2 as required.
The Frequency adjust slider bar is displayed:
4. Adjust the slider to the required value.
5. Select
Back to close the adjust frequency slider bar, or
6. Select Ok to set the adjust frequency to automatic.
Note: When manually adjusting the frequency the actual
frequency of operation is not displayed, the fishfinder
application title bar displays the transducers center frequency.
Fishfinder application
191