Furuno FAR-2107 - Manual (Page 69)

1. RADAR OPERATION
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1.26 Echo Stretch
The echo stretch feature enlarges targets in the range and bearing directions to
make them easier to see, and it is available on any range. There are three types
of echo stretch, 1, 2 and 3, and the higher the number the greater the amount of
stretching.
Note: The echo stretch magnifies not only small target pips but also returns
(clutter) from sea surface, rain and radar interference. For this reason,
make sure these types of interference have been sufficiently suppressed
before activating the echo stretch.
1. Roll the trackball to choose the ES indication at the left side of the display.
2. Push the left button successively to choose echo stretch.
Note: Echo stretch can also be adjusted from the PICTURE box.