Map Datum Selection

Fill Water With White

From the Map Page, press MENU↓ to MAP DATAENT. Press ↓ to FILL WATER WITH WHITE. With the option highlighted, press ENT to check it (turn on) and uncheck it (turn off.) After the option is set, press EXITEXIT to return to the page display.

Map Overlays (Range Rings; Lat/Long Grid)

The map screen can be customized with four range rings and/or grids that divide the map into equal segments of latitude and longitude.

Range rings are handy for visually estimating distances on the map. The ring diameters are based on the current zoom range. At a 100-mile zoom, the screen will show two rings with your current position in the center. The large ring touching the left and right sides of the screen is 100 miles in diameter (same as the zoom range). The second smaller ring is 50 miles in diameter (always 1/2 the zoom range).

The distance from your current position to the smaller ring (the ring's radius) is 25 miles (always 1/4 the zoom range). With the map cursor, you can scroll over to see the third and fourth rings. In this example, the distance to the third ring is 75 miles and distance to the fourth ring is 100 miles from your current position.

To set range rings: From the Map Data menu, highlight RANGE RINGS and press ENT to turn them on (check) or turn them off (uncheck). After the option is set, press EXIT.

To set Lat/Long Grid: From the Map Data menu, highlight LAT/LON GRID LINES and press ENT to turn them on (check) or turn them off (un- check). After the option is set, press EXIT repeatedly to get back to the main page display.

Maps and charts are based on a survey of an area covered by a map or chart. These surveys are called Datums. Maps created using different datums will show the same latitude/longitude in slightly different loca- tions.

All datums have a name. The GPS system is based on the WGS-84 da- tum, which covers the entire world. Other datums may cover the entire world or just a small portion of it. By default, your position is shown with the WGS-84 datum. It, however, can show your position using any of 191 different datums.

To change the Datum:

1.Press MENUMENU↓ to GPS SETUPENT↓ to DATUM SELECTIONENT.

2.Select the desired datum and press ENT.

640c, Mapping GPS Receiver specifications

Eagle Electronics has made a significant mark in the world of marine electronics with its innovative and reliable products, notably the Eagle Electronics 640C, 640cDF, and the 640c models. These devices are designed for anglers and navigators who seek advanced functionality combined with user-friendly operation.

The Eagle Electronics 640C is a high-performance fish finder that is primarily admired for its vibrant display and precise mapping capabilities. Equipped with a 640x480 pixel, full-color LCD screen, it provides crystal-clear visibility even in bright sunlight. This device uses advanced sonar technology to offer detailed underwater images, allowing users to locate fish with remarkable accuracy. The high-resolution graphics enhance the experience while providing an intuitive interface for easy navigation through its various features.

The 640cDF, a variant of the 640C, elevates the standard fish finder experience by incorporating dual-frequency sonar capabilities. This model operates on both 200 kHz and 83 kHz frequencies, allowing users to switch between narrow and wide beams based on their fishing needs. The dual-frequency technology provides a more comprehensive view of the underwater environment, making it easier to identify different types of fish and underwater structures. Additionally, the 640cDF boasts temperature sensing capabilities, giving anglers valuable data regarding water conditions that can influence fish behavior.

All models in the Eagle 640 series feature built-in GPS navigation. The integrated GPS provides a reliable mapping system that allows users to mark waypoints and create routes, significantly improving navigation efficiency. This technology is vital for those who engage in long-distance fishing trips or travel in unfamiliar waters. The GPS functionality, combined with the sonar capabilities, makes these devices essential tools for successful fishing excursions.

Furthermore, the Eagle 640 series devices come equipped with customizable display options, allowing users to tailor the information presented based on their preferences. The intuitive menu system simplifies the navigation of the device's various features, empowering users to quickly access critical data without unnecessary complications.

In summary, the Eagle Electronics 640C, 640cDF, and the 640c represent a blend of cutting-edge technology and user-centric design in the marine electronics space. With features such as high-resolution displays, dual-frequency sonar, built-in GPS navigation, and customizable settings, these devices enhance the fishing experience, making them invaluable assets for anglers and navigators alike.

Eagle Electronics Mapping GPS Receiver, 640c manual Map Datum Selection

Models: 640c Mapping GPS Receiver