Topic: SI water column clutter

[nater]

Hey guys,

I finally got out testing the SI unit.  I noticed this clutter in the water column which I didn't notice while looking around online a few weeks ago.  Any suggestions?

Sensitivity set to 10 as well.

Nate

[Humminbird_Greg]

nater,
Is the interference showing on the unit while on the water?
If so; does it only show when only XXX was running?  “XX” could be the trolling motor, another sonar unit, the main motor or anything else electrical on the boat.
Can you post a screen snapshot of this interference?

[nater]

Greg,

I was moving with my main motor at about 5 mph without my trolling motor down.  I do have a 788 up front and on but the transducer isn't in the water since its mounted on my trolling motor.  I noticed when I trim my motor all the way down it will actually block the left side image, no problem though.  Nothing to do with the this interference that I could tell.

I also made sure per instructions not to mount the si ducer inline with rivets.  This should help, but I could post a pic of the install location if that would help.

Nate

[sonar2000]

Yes, please post.  Pictures are always helpfull.  that way we can see what you see. and not guess.
Chuck

[Humminbird_Greg]

nater,
Next time out; shut your motor down and let you boat come to a stop and see if the interference is still there or not.  Than start your motor and take it out of gear and revving it up to see if the interference starts or not.  Let us know the results.

[nater]

Greg- I'll try that the next time out.  Here is a pic of the transom mount in case its needed.

Nate

[Phiznat5000]

Howdy! I think your issue may be the boat speed. With the standard transducer that comes with those models out of box - it seems anything around 5mph or greater will begin to cause that kind of distortion on your screen.

Conversely, if you are out in really rough water and are not moving very fast you can experience the same effects. My screen does exactly what you have shown in the picture above when I accelarate up to 5mph or more. Slow down to about 4 or high 3 and see if it clears. If its not something else it probably will.

[sonar2000]

I agree that it looks like a relationship between the transducer and the contact with the water...
I dont see it as interference (rf or otherwise) from something else as that type of interference will effect the whole screen left to right..
Chuck

[Phiznat5000]

I believe Humminbird sells a stronger transducer separately that will allow you to get better returns at higher speeds. And possibly greater depths? Im not as familiar with that transducer so I wont say much more. But if you need to scan at faster speeds, I believe the option is available in a different transducer.

[sonar2000]

I believe you are correct....but not in the SI type.  Or it could be the thru the hull transducer. 
Chuck

[Mark Saikaley]

I believe Humminbird sells a stronger transducer separately that will allow you to get better returns at higher speeds. And possibly greater depths? Im not as familiar with that transducer so I wont say much more. But if you need to scan at faster speeds, I believe the option is available in a different transducer.

The transducer for my SI unit is slimmer. It camth with the 997 CSI and I believe it is the same one on the 998 SI etc: XHS 9 HDSI 180 T.
Also while hard to tell from the photo but it does appear that the transducer is intstalled a little uneven and may not be quite parallel to the water  when launched. I have no idea it that would be a factor.  My boat does not produce that same sort of interference at those speeds. I have too many rivets and Ribs under my boat to completely avoid them with my transduce location all other factors considered but still have a very clean read out on a Sylvan Expedition Sport 17 ft 2008 with Yamaha F115  outboard. Also have full 180 disply with any motor trim setting

As an additional note with regard to interference... After a season of usage, the following season I found that there was increased interference at higher speeds where I was losing depth readouts when over 15 mph etc. It turned out that this was because the trandsucer had become "loose" where it joins the mount. I simply tightened the "friction" bolt and made sure the transducer was seated properly in its mount and the unit functions as it had originally at increase speeds. It turned out the angle of the transducer I believe was created more water turbulence until the angle was corrected back to the oringal installation and I was  a happy camper again

[slackwater]

It might help to check if your transducer is level if you took a full transom picture.
Then save to desktop open with ms paint or photoshop.
Now use your square box tool to check for level by comparing distance from the lines.
Example: