Topic: DI units vs SI units

[Speedtroller]

Why is the DI  image on the 2d DI units so much better than the DI image on the SI units. And is there a way to get it as good on the SI units.

[Humminbird_Greg]

The reason is the DI units use a single element in the transducer to produce the DI sonar image while the Si units use the data from the two Si elements in the transducer to form the Di sonar image.  While the DI units show a sharper image than the Si units, they do not cover as wide of an area as the Si units.

[Speedtroller]

Does this work better on the 455 KHz also. I guess this should be lumped together with the other post about the transducer KHz

[sonar2000]

speed, this is a good place for your question and it should be on its own thread. You have posted it ok and fine..
This way it will keep another thread from being hyjacked.
Chuck

[George]

I am thinking I would like to try a DI unit, it might be a better unit for the trolling motor.

George

[Humminbird_Greg]

Does this work better on the 455 KHz also. I guess this should be lumped together with the other post about the transducer KHz

On your 798 unit you only have the one Si/Di frequency – 455kHz.

If you had the option of 455kHz or 800kHz Di sonar (like the guys running the larger Si units do) you would be faced with the same options as with the Si sonar: wider and deeper coverage area with less detail (455kHz) or narrower and shallower coverage area with more detail (800kHz).

The DI model units are basically the same (wider beam at lower frequency, narrower beam at higher frequency) though they have a more limited coverage area.