Dual / Single Frequency Fishfinder; Non-Chirp (Traditional) Sonar Module Frequency Controls - Raymarine a67 Wi-Fi Installation And Operation Instructions Manual

17.9 Dual / Single frequency fishfinder

Dual frequency operation allows the sonar to operate and
display 2 frequencies simultaneously. If the preset mode that
you are using has two frequencies configured, you can view
either one or both of those frequencies in separate windows.
Selecting dual frequency view
From the fishfinder application:
1. Select Menu.
2. Select Presets.
3. Select Dual.
The main fishfinder menu is displayed.
4. Select View Freq.
5. Select the required setting:
• Frequency 1
• Frequency 2
• Both
Fishfinder application
17.10 Non-CHIRP (traditional) sonar
module frequency controls
The frequency of the sonar determines the width of the sonar
beam, the depth to which the signals will penetrate and the
resolution of the image.
The frequencies supported depend upon the sonar module and
transducer in use on your system.
• Auto. When operating in automatic the system will set and
the frequency automatically to suit your transducer operating
conditions.
• Lower frequencies (e.g. 50 kHz) produce a wide sonar beam
and penetrate the water well. Lower frequencies provide a
lower resolution image that may not be as good at detecting
small fish. Use lower frequencies if you require a large
coverage beneath your vessel or if you are in deep water.
• Higher frequencies (e.g. 200 kHz) produce narrow beam
and produce a high resolution image. They are most useful in
shallower water (up to 1000 ft) and at higher speeds.
The non-CHIRP sonar module will only operate at specific
frequencies defined by the connected transducer (e.g. 50 kHz or
200 kHz).
Setting the fishfinder frequency (non-CHIRP
sonar module)
With the Frequency settings menu options you can configure
frequency 1 or frequency 2.
1. From the fishfinder application select Menu.
2. Select Frequency settings.
3. Select Freq 1 or Freq 2 as required.
4. Select the required frequency:
Example of Frequency setting menu when connected to
a non-CHIRP sonar module.
Frequency tuning (non-CHIRP sonar module)
When connected to a non-CHIRP transducer there will be
an optimum frequency for the maximum sensitivity of the
transducer. The sonar module can be fine tuned to this
frequency.
Non-CHIRP sonar module frequency
120 130 140 150 160
1. Tuning range.
2. Transducer characteristics.
3. Operating frequency.
-50% +50%
170 180 190 200 210 220
1
2
3
D12574-1
189