NorthStar Navigation 8000I operation manual When to use 50 kHz, 200 kHz, or mixed frequency

2.The Auto Mode button shows the current setting. Select the button if you want to change to another setting and a drop down list appears. There are three choices:

ƒFishing - the range and gain settings are automatically adjusted to suit fishing conditions.

ƒCruising - the range and gain settings are automatically adjusted to suit cruising conditions. Use this when you're traveling at speed.

ƒManual - you can change the range and gain settings yourself. The sounder will store your most recent settings and use them until you change them again.

3.Select the new setting. The new setting is applied immediately and stays until you change it again.

NOTE: If you are operating the sounder automatically in Fishing or Cruising mode and then change the gain or gain threshold settings yourself, the sounder changes to Manual mode.

16.10When to use 50 kHz, 200 kHz, or mixed frequency

50 kHz is useful in deep water, typically greater than 500 ft (150 m) because it produces a good overview of area. 50 kHz generates a sonar cone that spreads over a wide, deep area of water with minimal loss of the return signal, but gives a lower definition display that is more prone to shadows than the 200 KHz frequency. This means, for example, that a small group of fish close to the bottom might be shown as a single object, and fish very close to the bottom might not be shown at all.

200 kHz is good in shallow and medium water, typically less than 500 ft (150 m), or while you're running at speed because it reduces noise from turbulence. It generates a narrow sonar cone that returns excellent detail over a small area. This can be useful if you're trying to identify the type of bottom and/or locate individual fish. It's also the best choice for reducing shadows when you're fishing in areas with hollows, rocks and ledges. 200 kHz is the default.

Mixed - combines both frequencies on one display screen. This can be useful if you're not getting good displays from a single frequency, because it uses the best return signals that are available from either frequency. However, the mixed frequency produces a much slower scroll speed compared to a single frequency.

106 Northstar 8000i Operation Manual