Thread: Discussion on Lowrance Elite 5 DSI/Chartplotter ....

http://www.bassfisher1.zoomshare.com...ngle_Chart.pdf

How do you change the format of coordinates? For instance I have several hundred waypoints in the old standard deg, min, sec format but so far have not found a way to change the default of just deg and min format.

Originally Posted by rnvinc

I can't find it now but I remember Tom posting some cone angles..

Something like...
3degrees
48degrees
60degrees

Tom can you repost the info and tell us where you found these numbers...??

Rickie

OK ... I found this...
http://www.google.com/url?sa=t&sourc...QR5P2llhphD9Rg

I'm pretty sure this is for the LSS-1 Structure Scan module....

We still have no verification of beam angles for a Lowrance dedicated DI model like the Elite 5 DSI...

Rickie

I used the chart that Kosmo posted and made a few trig calculations on the down imaging and determined that the down imaging is a slice (beam) of an approximate 30 degree cone angle from 800khz and 60 degree cone angle slice for the 455khz. I know nothing of crystal designs, but I have seen them manufactured. Cone angles are relative to the point of signal strength measurement anyway. Remember? -3db, -10db. It is not a linear measurement, but logarithmic. Size and shape of crystal determine the frequency.
Since the specs reference slice of cones, then I would suspect parabola which I remember not of. Ask Pan Man. He is a mechanical engineer and maybe could explain it better. The manufacturer's still have the tooth under the pillow..

Hope we not cluttering up ur post too much cp. Here is a good read with pictures. This company makes the towfish that my buddy Pat Hahs (KyHydrographx) uses for his sidescan projects.

http://www.imagenex.com/sonar_theory.pdf

Originally Posted by Cane Pole

Hope we not cluttering up ur post too much cp. Here is a good read with pictures. This company makes the towfish that my buddy Pat Hahs (KyHydrographx) uses for his sidescan projects.

http://www.imagenex.com/sonar_theory.pdf

Thanks, Tom .... that does show how the scans are read & interpreted, so it's good stuff to know.

... cp

Originally Posted by rnvinc

OK ... I found this...
http://www.google.com/url?sa=t&sourc...QR5P2llhphD9Rg

I'm pretty sure this is for the LSS-1 Structure Scan module....

We still have no verification of beam angles for a Lowrance dedicated DI model like the Elite 5 DSI...

Rickie

Pappy... I've been searching for three nights at work looking for verified beam angles of the DSI models...

I was able to find the link quoted above dealing with the HDS Structure Scan models but I cannot verify that any of this SS criteria applies to the DSI models....

I was also able to find a few instances where certain individuals eluded to a "45degree" beam angle but that would only pertain to 1 of the frequencies (probably the 800)... Even then, their comments seemed more of a "guess" than speaking from logged data somewhere....

The "depth vs coverage" chart link that was provided earlier in the thread also seems to refer to the Structure Scan models and doesn't clearly define as being able to pertain to the DSI models ...it does show coverage for the "down imaging" feature of the SS but that doesn't mean those same numbers to be applied to the DSI models that do not use the LSS-1 module xducer... The DSI models xducer is different then the xducer for the HDS SS, therefore it's got to have specs somewhere... But where..??

It's almost as if Lowrance doesn't want anyone to know what the beam angles for the DSI models are for sure...

Have you thought about calling Lowrance and asking them where we can locate the verified 455 and 800 DSI beams angles...??

Rickie

Originally Posted by Cane Pole

I used the chart that Kosmo posted and made a few trig calculations on the down imaging and determined that the down imaging is a slice (beam) of an approximate 30 degree cone angle from 800khz and 60 degree cone angle slice for the 455khz. I know nothing of crystal designs, but I have seen them manufactured. Cone angles are relative to the point of signal strength measurement anyway. Remember? -3db, -10db. It is not a linear measurement, but logarithmic. Size and shape of crystal determine the frequency.
Since the specs reference slice of cones, then I would suspect parabola which I remember not of. Ask Pan Man. He is a mechanical engineer and maybe could explain it better. The manufacturer's still have the tooth under the pillow..

Trigonometry - Wikipedia, the free encyclopedia