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Humminbird HELIX 7 CHIRP Mega DI GPS G3

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1,200' 2D
350' DI,
125' MDI,

AC Live

The HELIX 7 CHIRP Mega DI GPS G3 is one of the new Humminbird fish finder and chartplotter combos released in 2019. Its navigation features and capabilities are similar to the older HELIX 7 CHIRP DI GPS G2, but its sonar is different. As its name suggests, offers Mega Down Imaging sonar, and comes with the new Mega DI transducer. For reference, this is the Humminbird part number 410940-1. This unit is also referred to as HELIX 7 CHIRP MDI GPS G3.

Technical Details and Specifications

  • Display: 7″ diagonal, 800H x 480V pixel resolution, WVGA 16-bit color TFT, with LED backlight
  • Sonar: Dual Spectrum CHIRP, CHIRP Mega Down Imaging
  • Transducer: Transom XNT 9 HW MDI 75 T
  • Frequency and Coverage:
    • 2D Narrow Mode: 180-240 kHz / 25°
    • 2D Wide mode: 140-200 kHz / 42°
    • 2D Full mode: 150-220 kHz (adjustable) / 42°
    • Down Imaging: 440-500 kHz / 75°
    • Mega Down Imaging: 1075-1150 kHz / 45°
  • Depth Capability (with the included transducer):
    • Dual Spectrum CHIRP: 1,200 ft (365 m)
    • Down Imaging: 350 ft (106 m)
    • Mega Down Imaging: 125 ft (38 m)
  • Power Output: 500 Watts (RMS)
  • Power Input: 10.8-20V DC
  • Power Draw: 800 mA
  • GPS: Internal
  • Cartography: Humminbird Basemap
  • Routes, Waypoints, Tracks: 45; 2,750; 50 (20,000 points each)

Sonar and transducer

The Humminbird HELIX 7 CHIRP Mega DI GPS G3 offers two types of sonar, these being 2D Dual Spectrum CHIRP and Down Imaging. Of course, the Down Imaging sonar offers the Mega DI mode, with a CHIRP frequency between 1075-1150 kHz for the sharpest detail. However, the unit also offers regular CHIRP Down Imaging in a frequency interval of 440-500 kHz.

For Dual Spectrum CHIRP, the unit offers the same frequencies and modes as the HELIX 7 CHIRP GPS G3, these being Narrow (180-240 kHz), Wide (140-200 kHz) and Full Mode (150-220 kHz). The Narrow and Wide modes are fixed; however, the Full Mode is adjustable and you can select any frequency range within that interval.

The transducer included with the HELIX 7 CHIRP MDI GPS G3 is the new XNT 9 HW MDI 75 T. This transducer features a rugged design with a transom mount, and 20′ (6 m) of cable. It also has an internal water temperature probe. It backs up the unit’s 455 kHz and Mega DI frequencies, as well as Narrow, Wide and Full CHIRP modes for 2D. It uses conical beams for the Dual Spectrum CHIRP sonar, offering a coverage of 42° in Wide and Full Mode, and 25° in Narrow Mode. For Down Imaging, the transducer uses thin beams but considerably wider. At 455 kHz (440-500 kHz) the beam is 75° wide, while for Mega DI it’s approx. 45° wide.

When it comes to depth capability, with the included XNT 9 HW MDI 75 T transducer, this Humminbird fish finder system can scan depths up to 1,200 ft (365 m) in 2D, and up to 350 ft (106 m) in Down Imaging. The depth capability of the Mega DI beam is 125 ft (38 m). However, the unit can be paired with various 50 kHz capable transducers. If using a 50 kHz CHIRP transducer, the system’s depth capabilities can reach 3,500 ft (1,066 m).

Needless to say, the unit offers all the standard sonar features that the previous similar units had. It has the Switchfire function, Selective Fish ID, Bottom Lock, Real Time Sonar (RTS or A-Scope), Sonar Recording, Screen Snapshot, Depth Alarm, Fish Alarm, and more.

Navigation features

Like all the other new Humminbird units, the HELIX 7 CHIRP Mega DI GPS G3 includes the Humminbird Basemap platform for navigation. These are basic charts and don’t offer the detail of the Navionics charts. But nonetheless, they cover more than 10,000 U.S lakes with 1 ft depth contours, and also provide coverage for coastal waters, showing depth markers, buoys, hazards, marinas, nav-aids, and various other points of interest.

In case you’re not satisfied with the detail and data provided by the Humminbird Basemap charts, you can always upgrade the unit’s chart database to Navionics or LakeMaster. The unit is compatible with Navionic+, Navionics Platinum, LakeMaster, LakeMaster Plus, and SmartStrike fishing charts.

AutoChart Live is also a feature available with this unit. This feature gives you the possibility to create personalized charts in real-time. It uses the 2D sonar information and allows you to scan the lake or body of water where you’re fishing, in order to reveal its depth contours. The unit is capable of storing 8 hours of recording time.

Needless to say, the unit has a built-in GPS receiver. It has a GPS speed function and offers enhanced fixes via WAAS, EGNOS or MSAS. The unit can store up to 2,750 waypoints in its memory, offering various icons for them so you can personalize them better. It can also save up to 45 routes and 50 plotted tracks with up to 20,000 plots per track.

Finally, since it’s only a G3 unit and not a G3N, it does not support Radar or i-Pilot Link. However, it can provide data from AIS units.

Control unit features

The Humminbird HELIX 7 CHIRP MDI GPS G3 features an LCD display with adjustable backlight, offering excellent readability in direct sunlight even from sharp angles. It’s keypad operated; it does not have touchscreen technology. Its display is 7″ in diagonal with a pixel resolution of 800H x 480V. Evidently, it’s a color display, with a 16-bit color range, WVGA type.

The unit is IPX7 waterproof rated. This means it can support incidental water exposure such as splashes or rain, and even full immersions in freshwater up to 1m.

Since it’s a G3 unit and not a G3N, it lacks the Ethernet connector. It has three connectors, one for the power cable, one for the transducer, and one for the communications cable (NMEA 0183). It also has a microSD card reader with one slot. Therefore, you can add a microSD card with better charts, or update the unit’s internal software via data microSD card.

The classic Gimbal mount is included with the unit. However, an in-dash mounting kit is also optionally available. A unit cover is not included.

The Pros

  • Dual Spectrum CHIRP sonar;
  • CHIRP Mega Down Imaging and regular CHIRP Down Imaging sonar;
  • XNT 9 HW MDI 75 T transducer included;
  • Depth capability up to 1,200 ft with the included transducer;
  • Multiple sonar functions available, such as RTS, Bottom Lock, Selective Fish ID+, Alarms, SwitchFire etc;
  • Sonar Recording and Screen Snapshot functions;
  • Precision internal GPS;
  • Humminbird Basemap chart platform built-in;
  • AutoChart Live;
  • Supports Navionics+, Navionics Platinum, LakeMaster Plus, and SmartStrike charts;
  • Trackplotting, routes and waypoints functions;
  • 7″ display, 800 x 480 resolution, 16-bit color display, with LED backlight, providing clear images, easy to read even in direct sunlight;
  • IPX7 waterproof;
  • NMEA 0183 output;
  • Supports AIS an GPS heading sensors;
  • MicroSD card reader (1 slot);
  • Upgradeable internal software;
  • Gimbal mount included;
  • Fairly easy to install.

The Cons

  • The in-dash mounting kit is not included;
  • A unit cover is not included.

Bottom Line

The Humminbird HELIX 7 CHIRP Mega DI GPS G3 is a fish finder and chartplotter featuring Dual Spectrum CHIRP and Mega DI sonar, GPS, the Humminbird Basemap charts, and AutoChart Live. It also includes the standard XNT 9 HW MDI 75 T. It’s a mid-range fish finder and chartplotter, great for a wide array of boats, for both freshwater and saltwater.

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