Quickly and Easily Track Fish With a Humminbird SI

Humminbird is one of the most prominent names in the field of fish finder GPS systems. They've produced a long series of Humminbird SI devices with a reputation for reliability and ease of use. eBay has many different versions of these devices in excellent condition, so you can get ahold of the right device before you go out fishing.

General features of a Humminbird SI fish finder

These are some basic general features of the models in the Humminbird SI series:

  • Screen diameters of either 5, 7, 9, or 10 inches
  • A clear display that makes use of a glass-bonded lens
  • CHIRP Sonar technology included
  • Maps derived from Lakemaster, Navionics, and Hotmaps
  • Side-imaging technology
  • A maximum depth of about 1,500 feet
  • Sonar that sends pulses from 83 to 200 kilohertz
What are the different versions of the Humminbird SI?

Some of the major versions in Humminbird's SI series of models that all come with side-imaging are the following. The number in each model name refers to that model's screen diameter.

  • Humminbird Helix 5 CHIRP SI
  • Humminbird Helix 7 CHIRP SI
  • Humminbird Helix 9 CHIRP SI
  • Humminbird Helix 10 CHIRP SI
The Humminbord SI, transducers, and CHIRP sonar

Every fish finder system comes with a transducer, which is what allows it to construct images of the sea floor and give you the positions of various fish as you're out fishing. The transducer does this by sending out a pulse at a certain frequency. When the pulse strikes some object, like a rock, a fish, or the sea floor, it is sent back to the transducer and the transducer reads that returning pulse. From that reading, the transducer determines what kind of object the pulse has struck, how big the object is, how fast it is moving, and so on. The transducer then uses this to reconstruct an image of what is going on underwater so that you can have a good idea of where the fish you are looking for are. Humminbird SI models all come with a transducer that is effective for depicting the sea at a depth of up to 1,500 feet.

All Humminbird models also use CHIRP sonar, which means that they transmit a sweeping range of frequencies. Starting at the lower end of their range, they gradually increase the frequency of each pulse until hitting the higher end, and this gives a more accurate reconstruction of underwater topography.

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