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The image below shows a split frequency screen ...(credit to Peter at continuouswave)...
Same sonar history ... 200kHz on the left and 83kHz on the right ...
Explain why the 200kHz doesn't paint the pretty arch like the 83kHz does (in this example of the same echo targets)...
Attachment 274201
Rickie
Not sure, but I'm tuning in for the answers.
Darned if I know, I'm with Searay, waiting for the answer!
I had an answer, until I killed my own answer! LOL
Tell us !!! Is it the size of the cone angle?
Narrower cone? Fish goes from one side of cone to center and back out quicker with a narrower cone, even tho the cones are travelling at the same speed
Greater cone angle from the 83kHz (35deg) picks up more detail than the 200kHz (12 or 20deg).
... cp :kewl
I don't know what cone angle the 200 has but it looks like 12 degrees as a 20 would arch fish. The 83 is approaching 60 degrees at 3db therefore the fishes depth is in the cone longer.Quote:
Originally Posted by rnvinc
I AGREE ,CONE WIDER
Great job guys ... :ThumbsUp
Now let's look at the 2 most important factors that affect the difference in the way this example paints the 200kHz targets vs the same targets in the 83kHz ...
1. Time duration of the target in the cone beam ...
2. Target distance from xducer as it passes thru the cone beam ...
note: online right triangle calculators are cool
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Attachment 274204
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It's important to note that all makes of 200kHz are not exactly 20° ... And all makes of 83kHz are not exactly 60°...these beam angle values were chosen to show the comparison of how the echo target is painted in a "narrow cone beam" vs a "wider cone beam"...
Rickie
Thanks Rickie!! I like learning new stuff.
I'm a little smarter now, Thanks Rickie.
Example:
Attachment 179613
Good example rdjj ...Quote:
Originally Posted by rdjj71m
The fish echo at the bottom left shows the difference well ...
Rickie
Awesome, Gaining a lot of knowledge with these Quiz's. keep em coming.
I enjoy your quizzes Rickie and subbed to this forum. thanks! :ThumbsUp
Good stuff! Thanks for the education!
Your a heck of a teacher Rickie. A guy can learn a lot from you. Thanks
I like diagram quizzes ...
Makes the thought "stick" better ...
Thanks for the kudos guys ...
Rickie
Great info :ThumbsUp
Got too this one late.....good info Rickie....:ThumbsUp It not only represents the difference, but the basic reason for the fish arch.
Thanks for the info.
So I'm trying to drop a bouy right on top of a brush pile. I should be using the 200 degree sonar? Example in 35 ft of water
Yes