Topic: my new towfish

[abraquelebout]

hi all
new towfish
60m of cat 7a cable
1,25 m/15,3Kg
Lss2 / Hdsi
3 connectors
i Have
- 455/800 on Lss2
- 455/800 on hdsi
- T°
- 83/200
- Di (on lss2 at 455 and 800)
nice job and verry stable, for the fisrt time in water i found  5 pieces of navy artillery (may be 1809)
and a wreck
i post some screen shot

[rnvinc]

Great work abra...

My 1st experiments with the LSS 2 DownScan thru my 1197 is showing a "double image phenomenon" ...(structure in the water column is showing as "double image")

Have you seen this is your LSS 2 DownScan....??

Rickie

[Rickard]

Very nice work!
I see no steel wire or rope so it looks as if the cable takes the whole strain. Is this correct?
Rickard

[abraquelebout]

hi Rickard
yes the cable take the whole strain
for the DI i must test it again
for this first mission whe have bad weather, 19 to 25 knots of wind an 0.9 m max short waves
i plot the target and go on area in few days .
whe search so a B17 plane
in my test i thind HDSI take more Surface noise than LSS2, The lss2 coverage is better to
i don't know the utility of down for moment, i use right chanel in 455/800 to take the lss2 down, i think soft of unit are not good for down
to compare a dedicated unit (958 or other) = i must take time to test it again
navy artillery are good target, i thing make a test on it

[Rüdiger]

Hi Felix

Great work 
What kind of cable do you use and where to get it?

mvh
Rüdiger

[abraquelebout]

hi Rudiger
i use cat 7a SFTP
i find it at
http://www.destockable.fr/index.php/cable
103 € for 80 m
there's 8 wire and ground tresse and steel drain  inside

[Rüdiger]

Thanks for the quick reply.

[rnvinc]

hi Rickard
yes the cable take the whole strain
for the DI i must test it again
for this first mission whe have bad weather, 19 to 25 knots of wind an 0.9 m max short waves
i plot the target and go on area in few days .
whe search so a B17 plane
in my test i thind HDSI take more Surface noise than LSS2, The lss2 coverage is better to
i don't know the utility of down for moment, i use right chanel in 455/800 to take the lss2 down, i think soft of unit are not good for down
to compare a dedicated unit (958 or other) = i must take time to test it again
navy artillery are good target, i thing make a test on it

I am also using the LSS 2 DownScan element 455/800 thru the right channel of my 1197...

I have taken separate recordings (with beam select at 200, 200/83, and 83kHz)...(because the beam selection changes the screen scroll rate requiring different chart speed settings)...

This was suggested by Rickard to view the recording in Humviewer (which doesn't have the post-processing of the recording like the HB unit does)...

The "double image" phenomenon is showing in Humviewer in the Down Image pane and the SI pane (where the LSS 2 DownScan element is being processed thru the right channel of the HB unit)...

Please investigate with your setup when you get a chance...

I really want this LSS 2 DownScan element to work in my HB...but the "double image" phenomenon is just making the structure in the DI view look like I'm crossing my eyes to view the DI view...

Your towfish design and application are impressive...!!

I have a towfish being loaned to me ...but I'm not sure how effective or beneficial it can be for me in my shallow water home lakes...approx...30ft general depth...

Rickie

[Rüdiger]

If the image resolution so much better and therefore worth the effort with the LSS2 transducer?
Are there any comparable images?

mvh
Rüdiger

[Rickard]

Rüdiger,
I always use the LSS-2 since almost all my scanning is done with recording while searching for wrecks. The superiority of the LSS-2 is evident when inspecting recordings with a viewer on a computer. The difference in unit display image quality between a standard HB transducer and the LSS-2 is small. This means a fisherman doesn't have that much benefit from the LSS-2 while on water. For me, the LSS-2 is well worth the effort and costs. In fact, I can't imagine being without it. (Well, a successful Doubleducer can sometimes be an alternative....)
There are very few comparisons between transducer types. I presented one here: http://forums.sideimagingsoft.com/index.php?topic=4456.msg27666#msg27666
As Rickie mentioned, better sensitivity seems to be the primary advantage with the LSS-2. This could be an advantage also for the fisherman in some cases.
Rickard
 

[Klems]

I think you set the standard for towfish design with those images of the artillery.

How deep were you imaging? Would you also mind showing some more pictures of how you attached the cable to the towfish and the material you used? This, for me, has always been the hardest part. How are you securing this to your vessel?

does anyone in the United States know where to get some of this CAT7 S/FTP wire? I've seen a few suppliers overseas, but nothing here. This looks like the ticket for developing deeper scanning towfish.

Kevin

[abraquelebout]

hi
for my towfish i use 60 m of cat7a cable
i made it in strong 90 mm pvc pipe
fin's are surf fin's
for the cable it past on rope (1,6 m) fixed on genoa rail (barton 60 cm x 2,5 cm)
The rope tightens cable on 1,6 m when you tract it
there's nothing in the nose for taking more diver's weight if i want, equilibrate the towfish simply with the genoa rail
i take picture today at 455 and 800 khz of same object
yes the Lss2 ducer is better, for DI BAD RESULT
in thist picture the towfish today in 12 m catamaran of my brother
pict 2 rest of 1800 wreek at 455 with Hdsi
pict 3 same with Lss2
4 artillery at 800 khz with HDSI
5 same but LSS2 at 800
6 same Lss2 at 455
no problem Lss2 is better
today 9 pieces of artillery, 3 old wreek...a good day

[Klems]

Those are some great scans! Please let us know what else you find. I really like the ones of the LSS-2 in 455kHz.

Also thank you for the construction information. What did you use for the nose? That looks like a perfect fit for the PVC pipe.

[abraquelebout]

for the nose, i find an aluminium  bottle, i cut it stuk it to a  80 mm pvc pipe, i cast epoxy resin inside
good result.
for moment i find 10 artillery pieces, and 3 wreek in this site
2 are certainly vessels who sunk in 1809, they have 45 or 50 metters lenght
i read lot of scans make in site
this pictures is the rest of two 1809 war ship may be the "Brûlots battle of Aix"
the english navy give a lesson to french navy