Table 4: 491 echo sounder features (Continued)
Manual controls
Gain | 0 to 75 db |
|
|
Clutter | 0 to 9 |
|
|
Signal level | 0 to 5 |
|
|
Noise limiter | ON/OFF |
|
|
White level | Any single color |
|
|
Other | Screen color palette |
| Depth marker |
| Position marker |
| Zoom in/out |
| Shift |
|
|
Ranges | 15, 30, 60, 120, 200, 400, 800, 1000, 2400 feet |
| 5, 10, 20, 40, 80, 150, 300, 500, 800 meters |
|
|
Advance | 1/8 to 2/1 |
speed |
|
|
|
Depth units | Feet, meters, fathoms |
|
|
Installation | Include speed, temperature, gain, and transducer |
calibrations | type |
|
|
491 Echo Sounder Operations Manual | Page 69 |
