North Australian FISH FINDER TM forums

Hello

Has anybody on here got a humminbird sounder which is running 2 x sidescan transducers feeding into the sounder unit via a Y cable?

With only 1 transducer (mounted say on the RHS of the transom centreline), usually either the o/b motor leg or perhaps a pod creates an obstruction even if not directly in line.

This results in poor sidescan performance in the direction of the obstruction.

Raising the o/b leg sometimes helps but it doesn't eliminate the problem. You WILL get interference to some degree or other.

Humminbird provide a work-around by using a second exact same transducer mounted on the other side of the transom and fed into the sounder unit via a special Y cable.

Sounds complicated but its not. The special cable disconnects the LHS sidescan of the original transducer and instead connects the second transducer LHS sidescan to the sounder unit. THEN you have eliminated any adverse effect of the o/board leg or pod obstruction and get a good clear left sidescan shot.

The original transducer still provides the downscan/sonar stuff along with temp etc. (They're also disconnected from the new transducer via the Y cable).

I'm in the process of fitting the second transducer and will take some before and after screenshots to see if any improvement to the LHS.

In the meantime I'm interested to know if anybody has tried it on this forum?

Not sure of the y cable, but have heard of running 2 transducers to 2 head units and view left on one and view right on the other

Its the same issue on a Lowrance or any other sounder, Flickn. An obstruction is an obstruction no matter what type of sounder is in use. Cost is about $500 for transducer and Y cable.

Trent, the Y cable means you don't have to use a second head unit. On a Humminbird Helix the second sounder is about $3,000.

Its a simple plug-and-play installation.

I haven't heard of any of the other more common sounders with a work-around.

Lowrance have had that option since gen 1.
Also you can mount the transducer back the front under the hull then run the image in reverse.
this will have its own issues to deal with but its possible. hull or bracket mount.

Cheers

Thanks. Makes sense. Know anybody that's used it?

In the early days
saw it on a boat but not much better .
If transducer is tilted slightly forward and a little trim out when trolling i don't have seem to have the issue.

cheers

I think I've got too much spare time on my hands.
I can see a difference to left when o/b leg raised and lowered.

I'll get a couple of before/after shots for comparison. If there's negligible difference I've spent $500.

I noticed in the early days there was a slight difference, as the picture seemed a bit darker but was still clear.
with my new boat which has a different set up i have not really noticed it at all.

Bloke by the name of Chris Parris runs dual 'ducers I believe. Works well as far as I'm aware.

I'd run two transducers if I could

As long as right and left end up unimpeded I'll be happy. They're not at the moment.
Even lifting the o/b leg still allows reflection returns from close to the receiver which can and will degrade the performance. This sort of thing has got nothing to do with brand names.

New transducer and the correct Y cable for it arrived today so I'll let you know in a week or so.

Be interesting to see how it pans out

Will there be a gap in the middle of boat ?

Area not scanned like in lowrance diagram above ?

let us know the results

Cheers

fff1964 wrote: ↑Wed Jul 10, 2019 7:33 am Be interesting to see how it pans out

Will there be a gap in the middle of boat ?

Area not scanned like in lowrance diagram above ?

let us know the results

Cheers

Might need to run down scan on a split screen ?

No gap in the middle.

Everything will operate normally.

The LHS scan from the new transducer is fed into the head unit. The RHS scan and every thing else from the new transducer is disconnected by the Y cable.

The LHS side scan on the existing transducer is disconnected by the other leg of the Y cable.

Everything else on the existing transducer is still fed to the head unit as before.

So the head unit thinks that its business as usual.

I took some screen shots today showing the effect on sidescan to the left by the raising or lowering of the o/b leg.

Will put them up here tonight to show the problem.

Here's a screenshot of the o/b leg effect.
I picked a non-descript bottom with similar ground each side of boat.

The bottom half of the image shows the screen with the leg raised back and up from the transducer line which is mounted on the starboard side.

The leg gearbox etc isn't in line with the transducer. Its further back from the transom than the transducer but still interferes due to beam "leakage" at close range.

Port side image a bit darker. Note the bottom line where the beam meets the bottom on the left and compare it with where the beam meets the bottom on the right. Change line is less distinct on the left. Right is pretty clearly defined for a mud/sand bottom. Bit more bottom detail on the RHS.

Lesson 1 is that o/b leg still has an effect despite being raised.

The top half of the image shows when the leg is lowered. Bottom detail to left is nearly gone. It'd take a pretty strong return to been seen easily.

In addition, the bottom/beam line is practically non-existent.


Note also that there is no discernible image change on the RHS no matter where leg is.

after this dicussion i will have to do some research on my lowrance hds 9 gen 2 ,didnt realise there was that much interference with the leg