Topic: Interference Or Transducer Location....?

[basszilla]

Im getting interference from my outboard I believe.  I got rid of interference from the trolling motor by installing a ferrite ring that humminbird sent me.  My question is after looking at the type of interference I have, I am realizing it could be the location of my transducer.  Dealer said that where they install them all the time with no problem.   I am posting pics of the transducer placement and the interference I am getting on the dash mount Hummindird 998.  Transducer is mounted on jack plate.   It usually appears on the screen when I accelerate.  Any suggestions on what it might be? 

[rnvinc]

Your xducer setup may not be optimal for your 3.9mph scanning speed ...

Read this...
http://www.bbcboards.net/humminbird-sonar-gps/373911-help-hb-brother-out-imaging-problems.html

Rickie

[ITGEEK]

There's a simple way to tell if it's from your outboard.
Get up to scanning speed, then shut off the outboard.
If the interference goes away, you know it was that.
If your sonar is hooked to the battery the outboard is
charging, you will most likely get interference.
Get yourself a separate battery, only for the sonar.
It doesn't have to be a big battery.

From what I've heard, the slowest speed is the best scanning
speed.  You could be getting some water turbulence/water aeration across
your hull at 3.9mph.

[Humminbird_Greg]

I believe what you are seeing is due to aerated water getting up around the sides of your HDSi transducer.  If you look at the picture of the Si sonar that you took; you will that the interference only seems to affect the Si sonar returns of the lake bottom.  If it were electrical or RF interference it would also show in the water column (dark) area as well.  Mounting the transducer lower on the transom would help this at these speeds or you could just make sure and move at a slower speed.

Another way to determine if you are getting interference from the motor or its charging system is to get out on the water and with the motor out of gear; rev it to the same RPS level that you would normally see the interference at.  If it shows up again than it is coming from the motor, otherwise it is aerated water getting up around the transducer.

[basszilla]

Your xducer setup may not be optimal for your 3.9mph scanning speed ...

Read this...
http://www.bbcboards.net/humminbird-sonar-gps/373911-help-hb-brother-out-imaging-problems.html

Rickie

Looks like a winner. Ill be on the water tomorrow.  Let you guys know what happens. Thanks a million! 

[basszilla]

Bingo.   I slowed down a bit and was able to get some nice pics.  Down imaging has about three to four wiggly lines on the top part of screen.  Ill post pics of the DI.