JRC JFC-7050, Operation Manual

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Operation
Mode
Echo sounder modes are selectable for single frequency or dual and some functions, for example
bottom zoom or lock.
Press [MODE]
1. Normal (200KHz or 50KHz)
Normal mode (with Auto Range active) displays the sounder image with the surface at the top of
the screen and the sea bottom in the lower part of the screen. The depth scale indicates the depth
range appearing in the display. Bottom contours and fish echoes are displayed at the depths where
they are detected. If the depth Range is set manually to a value less than actual water depth, sea
bottom echoes are not displayed, but all other echoes within the Range setting are displayed.
2. Bottom Zoom (200KHz or 50KHz)
Bottom Zoom magnifies the sounder display from the sea bottom toward the surface for a short
distance. The sea bottom contour is displayed and additional contour lines are added at intervals
above the sea bottom to aid in determining distances of echoes near the bottom. Use the Sounder
Menu to set the magnified Bottom Range from 2.5 to 20m (10 to 60ft.). Default setting is 10m (40ft.).
If the depth Range is set manually, the setting must place the sea bottom echo in the lower portion
of the screen for Bottom Zoom to be effective.
3. Bottom Lock (200KHz or 50KHz)
Bottom Lock divides the Echo sounder main screen image for the selected Echo sounder into two
sections. The left hand section displays a Normal Mode image. The right hand section of the screen
displays the Echo sounder image relative to the sea bottom. The sea bottom appears as a straight
line with the Echo sounder image magnified for a short distance toward the surface. A scale
appears on the right for estimating distances of echoes near the bottom. Use the Echo sounder
Manu to set the magnified Bottom range from 2.5 to 20m (10 to 60ft.). Default setting is 10m (40ft.).
If the depth Range is set manually, the setting must place the sea bottom echo in the
lower portion of the screen for Bottom Lock to be effective.
Echo sounder modes are selectable for single frequency or dual and some functions, for example
bottom zoom or lock.