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What setting should you put a 1197si on in regard to the 800 or the 83 or the 800/83. Why does the finder show lots of fish in the color of blue and less in the orange. Example i was fishing in deep water anywhere from 30-40ft and when i put setting on 800/83 it shows some orange and the blue fish covers the screen?
I think its boils down to this. Your SI transducer has the ability to look sideways at two different frequencies. Either 455kHz or 800kHz. It also has the ability to look down at two different frequencies. Either 200kHz or 83kHz.
Now, when you see two different colors, the orange are the fish in the narrow 200kHz cone, and the blue are the fish in the 83kHz (wider) cone.
The higher frequencies will give you better resolution, but a shorter range. The lower frequencies will give you a lower resolution, but more range (especially to the side). If you don't use the unit in deep water, or care to see way out to the side, then the higher frequencies will give you more detail.
Hope that helps.
Thanks. When i changed from the 800khz and go to 800khz/83khz today it was showing a massive amount of fish and i was wondering why and wanted to know if there really was a massive number of fish under my boat or if something else was causing the false reading.
Now that I can't tell you. It would all depend on how your other settings and what was actually under you (I know that sounds like a given, but I would imagine the software that interprets the sonar return can be fooled sometimes).
Fishtaco is absolutely right.
There are more blue Fish ID Symbols because these are from the 83kHz beam that covers a much wider area of the water column than does the 200kHz beam. If you think that the 83kHz is showing too many fish, turn down the 83kHz Sensitivity menu.
Any sonar trying to determine real fish from other sonar returns can be fooled. We give you the option to change how the unit identifies fish by allowing you to adjust the Fish ID Sensitivity menu. Turn it up if you think the unit is being too picky about assigning Fish ID Symbols and turn it down if you think it is being fooled.
Those massive amounts of fish could really be part of a thermocline. Knowing the waters you fish will help you determine whether this is what it really is or not.
Which cone angle frequency (200kHz or 83kHz) is actually the "higher frequency".....??Quote:
Originally Posted by Fishtaco
What is the "maximum" range out to the side at the higher frequency..??
I took some snapshots of what i was seeing on finder and will get them posted and hopeful someone will help me understand what it is showing me.
Rnvinc,
Depends on which you are meaning here: the 2D or Si frequencies.
For the 2D frequencies the 200kHz will be the higher frequency and due to the shape of the element inside the transducer that produces this frequency it has the narrower cone angle. At the -10db point it is approximately 0.35 times the water depth. So at 10 feet deep the beam will be about 3.5 feet wide and in 50 feet of water it will be about 17.5 feet wide. That means that the beam is only covering 1.75 feet out to each side of the transducer when in 10 feet of water (half the width of the beam) and only 8.75 feet out to each side when in 50 feet of water.
The 83kHz beam is the lower 2D sonar frequency and has a wider beam due to the shape of the element inside the transducer. At the -10db point it is approximately 1.0 times the water depth. So at 10 feet deep the beam will be about 10 feet wide and in 50 feet of water it will be about 50 feet wide. That means that the beam is covering 5 feet out to each side of the transducer when in 10 feet of water (half the width of the beam) and only 25 feet out to each side when in 50 feet of water.
The Si frequencies are a little different. The higher frequency is the 800kHz beam and it only covers an area about 72 degrees. The 455kHz beam may be the lower frequency beam but due to the shape of the element being used it is the wider beam at about 86 degrees. Now even though these beams were measured in a lab at the -10db point what we have found through usage (and users have confirmed) is that the 455kHz Si beams effective cone angle (what you would experience during usage) is far wider as many can confirm that they in fact overlap.
The maximum Si sonar range will depend on several factors like the water quality, whether anything is blocking part of the Si sonar, wave conditions and the actual water depth. Usually its hundreds of feet.
Greg and Jason, you are definately a wealth of information and I appreciate your willingness to help....Quote:
Originally Posted by Humminbird_Greg
Does each sonar feature (2D, DI and SI) have it's own separate element inside the transducer so that the sonar frequency of each (2D, DI and SI) can be set individually..??
There are separate elements inside the transducers for the 2D and Si sonar (the Di sonar will come from the Si data so it uses the same ones as the Si sonar does). You can set the 2D sonar frequency separately from the Si sonar frequency.