Furuno FSS-3BB, Operator'S Manual

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1. OPERATION
1-16
1.7 How to Adjust the Gain
Depending on the signal strength, gain can be adjusted to hide noise and other un-
necessary echoes. A high gain setting increases signal strength and can show exces-
sive noise as well as smaller, hard to detect echoes. A low gain setting eliminates
noise and gives a clearer picture, however smaller echoes may also be removed.
To adjust the gain, do as follows:
1. If the header is not displayed, put the cursor at the top edge of the display to show
it.
2. Click the [GAIN] indication on the header. The indication is now highlighted in a
green color.
3. Select one of the following gain adjustment methods.
• Click the [GAIN] indication again. Each click changes the mode indication in the
GAIN header in the sequence of [HF] → [LF] → [ID] → [HF]... (inactive modes are
skipped). For example, the [MODE] indication currently shows [LF/HF]. Then,
each click of the [GAIN] indication shows [HF] or [LF] in the [GAIN] indication.
Further, the red frame encloses the mode and gain setting indication (top-left
corner of each image) of the image currently selected for adjustment.
• Click the “Mode and gain settings indication” of the image that you want to ad-
just. The indication clicked is enclosed with the red frame, and the frequency
indication in the [GAIN] indication changes accordingly.
4. Scroll to change the gain.
Scroll downward to increase the gain; upward to decrease the gain. The current
gain setting appears in the [GAIN] indication. Adjust it so that a slight amount of
noise appears on the screen. In the case of low- and high-frequency echoes, the
settings are applied to the past images displayed on the screen. For the IDENTI-
FISH
™
echoes, the setting is applied to the image from the point of adjustment.
Too high Proper Too low
NOTICE
Adjust the gain properly.
Too little gain may present no picture.
Too much gain shows excessive
noise on the picture.
Picture being adjusted
Mode and gain setting
Red frame (mode currently selected)
[GAIN] indication