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That's a very good description Vik ....well done....
Your "swingscan" ...as you call it...is definitely very interesting.....
Are you using a Down imaging unit with 1 down image crystal on a certain degree angle from direct vertical to garner the images that you have posted...??
Rickie
Hey Vik, what does it look like on those images when all that is at the 2:00 position off the bow 75-100 feet from the boat?
Rickie,Quote:
Originally Posted by rnvinc
yes, I posted the images using Down imaging unit with 1 down image crystal on a 40 degree angle from direct vertical:
http://www.crappie.com/crappie/fishi...b-346c-di.html
I think you will be seprised, but I used two DI transducers with that tiny unit Humminbird 385 ci DI as well, and had seen both sides in one ice hole:
http://s017.radikal.ru/i435/1301/de/96097f33d25b.jpg
http://s019.radikal.ru/i614/1301/c9/8173cf55ed8e.jpg
You can see on screenshots above that it can get images 40m from boat, or 120 feet using that technick. I got imagies 60m away of boat, or 180 feet. Humminbird 385 is small, but it is powerful -4000W.Quote:
Originally Posted by Stymie
Is the 40° angle from direct verticle a critical measurement in this application or would you adjust that angle according to the water depth...??
Rickie
It depends on which frequencies I am going to use it: if it is 75 degree beam (455Hz) I set angle up to 40 degree, if it is 45 degree beam (800Hz) I set angle up to 25 degree. Also it depends on which images I am going to get: If I want to get SI as far as possible of boat - I increase angle, if I want to get more distinct DI - I decrease angle.Quote:
Originally Posted by rnvinc
What is your mechanical system to get a good smooth, "non-jerking" sweep...??
Teflon on Teflon...?? Bearings...?? Gears...??
Rickie
Unfortunally none of them :(. One year ago, before publishing this, I suggested Humminbird to manufacture proper mechanism on that idea, but they said that they have a lot of their own ideas for 5 years ahead. I wrote the same to Lowrance then – they did not reply at allQuote:
Originally Posted by rnvinc
http://s002.radikal.ru/i197/1301/ea/628ca5aa91df.jpg
If you're just creating the "sweep" by holding the cable...you're doing an amazing job of a fluid sweep...
You're images show no jumping or jerking at all...
I see you are in Alaska...is that your homeland...??
Rickie
Sorry, I am not in Alaska. I work in American Oil Company, and at the moment I am on rotation at Noth-East of Caspian Sea, and will return to my sonar in three weeks.
I was born in Russia, but live in Kazakhstan. You can see where my screenshots were taken by coordinates on them.
The legth of cable is 50 feet (20+30), but it works pretty stable and even.
Viktor