Author Topic: Interfacing a HB with the Lowrance LSS-2. (Read 133729 times)

Rickard · « **on:** July 10, 2012, 04:20:23 PM »

Hi,

I can report the Lowrance HD LSS-2 transducer can be used with a HB unit, at least with my 981. The LSS-2 makes it possible to get narrow SI beams, as narrow as with a "Doubleducer", but with less work, lower cost and probably with better over-all performance than what's possible with a homemade Doubleducer.

There is one complication, the LSS-2 has no downward 200 kHz channel. HB SI units use depth to control ping rate in the SI channels so the LSS-2 must be supplemented with a 200 kHz depth sensing transducer (almost all HB transducers can provide that). (Maybe there is a Y-cable that can facilitate the combining of the 200 kHz and SI/LSS-2 transducer?). The LSS-2 cannot be operated at 262 kHz, but it wouldn't come as a surprise if it can be used at 800 kHz, even if that's not stated in the manual. (I can't test at 800 kHz with my old 981.)

I couldn't get any wiring diagram or pin layout for the LSS-2, but some simple tests were all that was needed. I have indicated the function of the pins in the image. There are two ground pins with unclear function. One could be ground for temp and the other is probably a shield ground. None of the ground pins are needed to get SI work. Two pins are for the DI-channel, I don't use them either. Only the pin pairs for left and right SI channel must be used.

I have tested for one hour with a provisional arrangement and with the transducers hanging from a quay. I will be back with results from real scanning and with comparisons with the standard SI transducers.

Disclaimer: I can't guarantee there is no risk for damaging a unit. Anyone who tries this must do it at his/her own risk.

Added: My former reservation on the function of the upper, middle pin is withdrawn. That pin is positive temp, as indicated in the image. The ground pins should be connected to ground in the HB system. Testing showed this reduced noise to a noticable extent. The reason for two separate grounds is still not known.

Rickard

Roddy · « **Reply #1 on:** July 10, 2012, 06:56:22 PM »

Rickard, Hummmmmm I might try this with my old 987. Thanks for the pin out. post some screen shots!

Roddy

Bob B · « **Reply #2 on:** July 10, 2012, 07:08:06 PM »

Rickard, Thanks a lot for the info.....knew you could figure it out.

I've got too many things in the works right now to give this a try, but will be eagerly waiting to see your scan comparisons and may do the project when I get time.

LocDown · « **Reply #3 on:** July 11, 2012, 12:11:20 AM »

also waiting for results

offroad · « **Reply #4 on:** July 11, 2012, 02:11:01 AM »

+1

Rüdiger · « **Reply #5 on:** July 11, 2012, 03:58:08 AM »

Hi Rickard

Thank you for your courage to risk your unit.

I'm really looking forward to the primal scans.

mvh
Rüdiger

ITGEEK · « **Reply #6 on:** July 11, 2012, 09:11:29 AM »

Rickard,
You really push the envelope on this tuff.
Way to go.

Whistler · « **Reply #7 on:** July 11, 2012, 05:43:24 PM »

Rickard,

What type of coverage area do you anticipate getting with the LSS2 transducer? I realize the beam width will be narrow due to the increased length of the piezo, but how about the beam angle?

Rickard · « **Reply #8 on:** July 11, 2012, 06:26:11 PM »

Whistler,

All I know is that Lowrance states a range of 250 - 300 feet to each side at 455 kHz. Lowrance doesn't present the vertical beam angle. Range could be different with a HB unit because of bad impedance match. Not using the down imaging array in the LSS-2 will reduce the interference stripes which Lowrance users must live with, this is the only prediction I dare make. I must wait a few days with my on water tests (I must entertain guests...), but I will report as soon as possible.

Rickard

Rickard · « **Reply #9 on:** July 13, 2012, 07:21:41 PM »

At last I got a few hours for testing on water. The conditions were not ideal with some wind which is a problem for my 12 feet, 65 lb folding boat. To begin with, the unit couldn't recognize the transducer and started simulation. This didn't happen in the first test. When the system was forced to operate in normal mode everything worked fine. I suppose the rat's nest connections is the explanation...
The test rig was pole mounted.

I try to upload some examples. The titles appear below the images. I should not manipulate your perceptions, but my very clear impression, especially when I was out scanning, was that the combination with the LSS-2 gives excellent results. I have some recordings with a homemade Doubleducer from the same targets and the LSS-2 beats those also. I will do some more testings and see if there are any long term effects on the unit and if there is any use for the ground circuits in the LSS-2.
Today I feel I will scrap the Doubleducers and go for the LSS-2.
Rickard

offroad · « **Reply #10 on:** July 13, 2012, 07:45:55 PM »

Sounds good ,,,,Question for you...Do you need there black box ? l have access to a LSS1 transducer maybe l should try it ?
l have a couple of old HB Transducers l could cut the cord of one of them

Rickard · « **Reply #11 on:** July 13, 2012, 07:53:37 PM »

The Lowrance control box is not needed, just the transducer (they call it skimmer). The LSS-1 can't be expected to give better results than the HB SI or HDSI transducers since they are the same length.

Rickard

Bob B · « **Reply #12 on:** July 13, 2012, 08:53:20 PM »

Rickard, It looks like the image is sharp, but may be loosing signal at the outside of the range. This is the same problem Lowrance has with the Lss-1 and 2. What was your range setting?
I thought it was because of the additional software filtering they were doing to reduce the DI interference, but maybe it is the beam angle of the transducer?

Rickard · « **Reply #13 on:** July 14, 2012, 04:28:29 AM »

Bob,
Depth was around 12 feet and range was set to 100 feet (30 m). This range setting is far beyond what's considered useful at such depth. On water I noticed that the LSS-2 is much more sensitive than the standard HB SI. In fact, I had to set sensitivity to 15 with the SI transducer to see about the same result as with the LSS-2 set to 10. I think the inclination of the beams in the LSS-2 is about 30 degrees, same as in HB transducers, and the vertical beam width must be wider than in the SI 160 because there are no traces from vertical sidelobes. (The gap between mainlobe and first sidelobe show like a dark, fuzzy band on the sea-floor close the water column with the SI 160. This band is gone at 455 kHz with the newer HDSI 180 transducer.) A beam inclination at 30 degrees is good in a hull mounted application, but a bit too steep for use with a towfish.
Rickard

abraquelebout · « **Reply #14 on:** July 14, 2012, 04:58:34 AM »

hi rickard
intersting result,
do you make a difference between lls-2 and double ducer ?
i thing it's the same result, long array in llss-2 give more détail and better range
if you have pictures in double ducer vs lls-2 would you post them.
do you lost the 800 khz with the lls-2 ducer ?

Rickard · « **Reply #15 on:** July 14, 2012, 06:44:12 AM »

Abra,
I have no images from the Doubleducer and the LSS-2 which allow for fair comparison. But I have looked through several recordings from the same area and it's obvious the LSS-2 is superior. I have two Doubleducers and each of them has a good and bad channel, one has good left SI and the other has good right SI. The LSS-2 show the same performance in both channels. In theory, both the Doubleducer and the LSS-2 should have the same horizontal resolution because they are the same length, but the practical issues with making a Doubleducer use to cause some deficiencies. My Doubleducers are made from SI 160 transducers with 262 kHz capability which is very good for long range/deep water scanning, especially when a long cable is used which adds alot of attenuation. Since the LSS-2 is so sensitive this can possibly compensate for attenuation in a towfish application and make 455, and perhaps also 800 kHz more useful with long cables.
I can't test the LSS-2 at 800 kHz with my 981, but the US manual on the web tells the frequencies are 455 and 800 kHz. The international manual states only 455 kHz. The manual sent with my LSS-2, sent from the US, states only 455 kHz. Someone with a 800 kHz unit must test the LSS-2 so we know what's true.
Rickard

keizerh · « **Reply #16 on:** July 15, 2012, 06:55:50 AM »

Rickard,

Nice to see you use the LSS2.

LSS2 can use both 455 as well as 800 kHz on my NSE.

I suppose the cable type is the same as the bird's SI?
So the I can start to make a LSS2 towfish

Rickard · « **Reply #17 on:** July 15, 2012, 07:16:43 AM »

Keizerh,
I haven't cut the LSS-2 cable yet, It's easier to connect test wires to the connector pins as long as I'm in the testing phase of this. The cable feels thicker than a HB cable, and it's most likely a high-end twisted pair signal cable, but not an ethernet cable. Remember, the LSS-2 transducer must be used with a 200 kHz depth sensing transducer, so two transducer cables must be joined to a common cable to the surface. I don't expect any severe issues when doing that.
And thanks for the info on 800 kHz! Now many of us will be more tempted to try this for sure!
Rickard

Rickard · « **Reply #18 on:** July 18, 2012, 05:39:53 PM »

Friends,
After about 15 hours with testing I think it's time to present a wiring diagram for the combined HB - LSS-2 high definition sideimaging system. The setup has been tested in different conditions without any signs of damages to either the unit or the transducer. The system may have to be started by forcing normal operation at startup, that's the only sign of this sytem is not fully adapted to a HB unit. The system starts automatically if it is started with the transducers out of the water.
I must say I'm pleased with the quality of the images so far!

Added:
Latest testings with 50 m with ethernet cable showed the unit starts up normally without need for forcing normal operation. Image is excellent, although sensitivity must be stepped up a few levels. I can't say much about the difference in sensitivity between a Doubleducer and the LSS-2 when they are used with 50 m with cable. The impression is the LSS-2 performs better.

Rickard

Bob B · « **Reply #19 on:** July 18, 2012, 06:06:36 PM »

Thanks Rickard

offroad · « **Reply #20 on:** July 18, 2012, 06:35:01 PM »

Yes thanks +2 Still looking at ways to connect the two transducer units together l have a old Lowrance tranducer and a HB one as well ,The Lowrance one is a smaller one than the HB, So l am thinking l might go... LSS2 Sidescan unit/ Lowrance 200Khz connected to a spliced HB cable. Still waiting for the LSS 2 to arrive Not cheap $300 landed

Rickard · « **Reply #21 on:** July 19, 2012, 01:45:28 AM »

Thanks all,
Trevor, you can use any transducer with 200 kHz capability for depth sensing, not only a HB transducer. A HB transducer will come with an appropriate connector, though.
Rickard

LittleGazoo · « **Reply #22 on:** July 21, 2012, 12:29:22 PM »

Wouldn't the front mounted Lowrance transducer cause water disturbance on the rear mounted HB transducer?

Rickard · « **Reply #23 on:** July 21, 2012, 02:56:40 PM »

LittleGazoo, Yes, it will certainly cause water disturbance, but such turbulence has no effect on performance at all. Sound speed in water is too high for that.

Regards,
Rickard

Rickard · « **Reply #24 on:** July 24, 2012, 06:59:01 AM »

The combined LSS-2 - HB transducer (should I call it the LowBird system?) setup has now been tested with 50 m with ethernet cable, but not with a towfish. There is no degradation of image quality other than a general lowering of signal level. I can't say for sure if it's at the level of a Doubleducer, but it looks very good. The problem with having to force normal startup vanished!

I present an image from SiView that shows pretty well how the system performs in the hull mounted version. No editing of the raw HB/son2xtf/SiView data. Depth 30 feet, range 120 feet. The location is Bergnäsbron in Luleå river in Sweden. There are traces from interference between left and right SI close the water column, but not more than in any two-sided sidescan system.

Rickard

abraquelebout · « **Reply #25 on:** July 24, 2012, 08:01:02 AM »

nice job
lowbird work well
do you have the size of yhe lss2 ducer ?
i think it's so easy to make towfish with lss2 than hdsi ducer
i wonder if i do this, a lls2 cost about 320 €, if there's 455 and 800 khz, it's a good solution...
thank's to publish your result.

Rickard · « **Reply #26 on:** July 24, 2012, 10:29:25 AM »

Thanks Abra,

The straight part of the LSS-2 is 200 mm and I think the arrays inside have about that length. Since the arrays in the Doubleducer are 220 mm the Doubleducer should be slightly better, but the difference is negligible. Both are significantly better than the standard HB SI transducers and the LSS-1. At 455 kHz the one-way -3 dB beam widths in the standard transducers are about 1.6 degrees and in the Doubleducer and the LowBird the figures are half of that, 0.8 degrees. The only way to make the Doubleducer beat the LowBird in all respects is complete reconstruction like Sea-Rover did.

Rickard

Bob B · « **Reply #27 on:** July 24, 2012, 06:31:07 PM »

Looks great Rickard.....I think it works much better on the bird than on the intended unit. Don't see any indication of going dark at the outsides.

Whistler · « **Reply #28 on:** July 24, 2012, 07:08:20 PM »

Rickard,

The detail and clarity of the images produced by the lowbird seems impressive, but there also seems to be some problems with the images. Upon close inspection it looks like there is noise in the latest image you posted (visible at the bottom of the water column) and in some of the earlier images you posted there seems to be some significant ghosting on the image (in the second image you posted you can see the wall on the left side also reflected on the right side). Do you have any ideas what may be causing these issues and whether or not it is something you might be able to eliminate?

Rickard · « **Reply #29 on:** July 24, 2012, 07:38:43 PM »

Bob, I think one reason why the images seem better with a HB is the interference from the structurescan/DI array in a Lowrance unit. Since I don't (can't) use the DI array that issue is gone.

Whistler, if you mean the noise close the transducer it's mostly caused by reflections from the hull and the surface. If you mean the tiny bars on the sea floor I recognize them from other images from HB transducers (actually Doubleducers). I don't know why they appear, but they could indicate oscillation of something in the system, or they are software artifacts. The ghost-wall is typical with any transducer if something as reflective as that steel wall is passed. I think most of it is caused by sound that simply sneaks in from behind into wrong array.

Rickard

Rickard · « **Reply #30 on:** July 25, 2012, 02:51:41 AM »

I have been informed my experiments have been discussed and the LSS-2 + HB concept has been criticized on other forums. I have no time now for going into detail, but the first image examples from the LSS-2 were taken without use of grounds and shields in the LSS-2. This caused a high, general noise level and a very salient ghost image of the steel wall. These issues were solved by using ground. Look for the details, not the noise!

The LSS-2 image below is from the same location, but from the opposite direction and closer the steel wall, and with use of ground.

Rickard

SonarTRX · « **Reply #31 on:** July 25, 2012, 03:43:00 PM »

Hi Rickard,

Have you tried to see if the slight bar-code pattern (seen along the seabed) will go away if you just use the 200 kHz mode?

The slight bar-code pattern in your image look similar to the problems we found earlier:
http://forums.sideimagingsoft.com/index.php?topic=3890.msg23342#msg23342

i.e. ...Whenever the 83 kHz option is in use (or the 83/200 mode) there would be a degradation in quality of the recorded sidescan data.

Tore

Rickard · « **Reply #32 on:** July 25, 2012, 04:41:51 PM »

Tore,

I will try with the 200 kHz only setting next time I'm out. But I have found the other recording issue, the gaps, get worse with only 200 kHz, therefore I use 200/50 or 200/83 kHz as routine when recording. I think the gaps do more harm than the bar-code does.

Rickard

abraquelebout · « **Reply #33 on:** August 27, 2012, 01:13:41 PM »

test lss2 with towfish
i cut the lss2 cable and solder it in hdsi cable
i take the Rickard wiring diagram
i cut yelow cable and orange in hdsi cable and soldering lss2 cable in the part of cable to go at hdsi connector
and soldering other ground in ground hdsi cable (not cut)
diagram
best quality for lss2, every thing work well in first connect to unit
lss2 work in 455 and 800 khz
the way is open to long cable towfish

Rickard · « **Reply #34 on:** August 27, 2012, 01:28:10 PM »

Fantastic abra!
Thanks for the simple color code for wiring. Now we know for sure that it works well also at 800 kHz, and with good range. Yet another smoke proof Humminbird.

Good luck with the towfish, you will probably be the first on this globe with a LSS-2/HB towfish system!
Rickard

Rüdiger · « **Reply #35 on:** August 28, 2012, 03:30:56 AM »

Hi Felix

Congratulations really good pictures.

Please post a picture of the towfish doublesducher arrangement and how did you seal the cable connection?

mvh
Rüdiger

abraquelebout · « **Reply #36 on:** August 28, 2012, 05:00:22 AM »

hi rudiger
for moment it's prototype (i arrange my first towfish)
the definitive is in study
for sealing i use sinto marine mastic who serve to seal in marine for windows and other thing
i make same arrangement as rickard do
i joint other comparative picture

Rickard · « **Reply #37 on:** January 13, 2013, 01:58:56 PM »

Hi,

I made a few scannings with the rotation metod using a LSS-2 in combination with a Humminbird Quadrabeam transducer (for depth sensing) and 150 feet cable. The results were as good as with a Doubleducer. The image shows a small (14 feet) boat with what seems to be an outboard. Depth is 25 feet. It was a bit cold, dark, 2 feet with snow and problems with battery connection etc, but the results were ok./ Rickard

sonar2000 · « **Reply #38 on:** January 13, 2013, 02:25:40 PM »

Excellent work. Maybe between the two pieces of equipment we can start to see what is under the water.
Many pats on the back to you..

Chuck

Rüdiger · « **Reply #39 on:** January 14, 2013, 03:17:39 AM »

Hi Rickard

Once again an excellent picture.
Have you scanned the same wreck ever with the old configuration, would be good even to have a direct comparison?

mvh
Rüdiger

Rickard · « **Reply #40 on:** January 14, 2013, 06:38:35 AM »

Thanks,

Rüdiger, it would be nice and scientific to make direct and fair comparisons, but I don't use the standard transducers anymore. They are joined into Doubleducers or mounted to the hull of my boat and some are stowed in drawers, awaiting other projects. I know from earlier comparisons that the Doubleducer is clearly better than the standard transducers and the LSS-2 has somewhat higher sensitivity than the Doubleducer, which gives the LSS-2 a bit better range performance. The better resolution with the Doubleducer and the LSS-2 is actually a trivial phenomenon since long element arrays must, because of laws of nature, produce narrow beams.

(The wreck in the image was registered for the first time this summer with a hull-mounted LSS-2.)

Rickard

abraquelebout · « **Reply #41 on:** January 14, 2013, 01:14:19 PM »

nice picture, may be a ryds with a outdoors motor, the hull is break on left verry good picture
for other subject
i use Opencpn
i join on it a small search and rescue plugin, it make beautiful grird and generate gpx
i join pics of this system

this gird is made in one minute, you choose a point, distance long and espacement, number of vector, inclination and go
verry nice aplication and free.....

sjefsrafsern · « **Reply #42 on:** January 15, 2013, 03:25:30 PM »

Hi, i like the quality of your images.

have any of you guys tried the lss 2 on the transom and used it to find fish? if so, did the lss find more fish/is it easier to see the fish with the lss? i think i saw some baitballs and fish on one of the images above, but they did not appear on the matching humminbird ducer image...?? is this because the lss is better or is there another reason? (i dont like to miss out on details like that...)

mvh stig

Rickard · « **Reply #43 on:** January 15, 2013, 03:54:23 PM »

Hi Stig,

Of course I have looked for fish even though I primarily use sonar for wreck searching. You can see fish in the images in the 10th post above. The names are Kista 160 SI 160.png and Kista LSS-2.png. Small fish, probably herrings, are visible with both transducers. Perhaps the LSS-2 image shows a bit better defined individual fishes, but the difference is small. The images are from different runs the same day. I can't say there is any practical difference between the transducers when it comes to fish finding.

Regards,
Rickard

abraquelebout · « **Reply #44 on:** January 16, 2013, 07:29:11 AM »

yes, whe can see fish

lss2 455 khz
and this is a jellyfish at 800 khz Lss2 60m câble

i remember this day, towfish it a big one of this, and it make this picture

sjefsrafsern · « **Reply #45 on:** January 16, 2013, 03:31:43 PM »

thanks for nice answers, of course the images are from different runs, and fish will appear difrent in the images. but its nice to know your thougths, and its good to know im not missing out on anything. (and dont need to spend a lot of money on a lss 2)

regards stig

sonar2000 · « **Reply #46 on:** January 16, 2013, 05:54:49 PM »

Are you sure that is a sonar recording or snapshot of the jellyfish. It looks more like a camera picture.
Chuck

Bob B · « **Reply #47 on:** January 16, 2013, 06:59:23 PM »

I think the picture represents what is in the SI snapshot below it.

abraquelebout · « **Reply #48 on:** January 17, 2013, 03:52:53 AM »

yes, for the jellyfish i'm sure
800 khz, Lss2, the towfish hit most of them in this scan sequence and before.
in hour country this jellyfish can take 1 or 1,5 m length and there's lot of near Fort Boyard (Oléron Island)

sonar2000 · « **Reply #49 on:** January 17, 2013, 12:08:29 PM »

Bob B....that makes more sense. I was struggling with the view.....Glad he included both. Makes it nice to see in reality what the sonar is representing..

Chuck

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