Humminbird 597ci hd problem

[Carl S]

I just installed a Humminbird 597 ci hd with a transom mount xducer on a PT185. The problem I am having is that I lose the sonar picture at high speed (30-40mph). The digital depth readout seems to work ok, but the sonar screen picture gets very "snowy" and you can not detect bottom contour.

I have the screen speed at max and the sensitivity set at 1 out of a 20 max. With the sensitivity set that low I can eliminate some of the "snow" but it is still hard to detect bottom contours.

I had a Humminbird 400TX prior to this install and had no problems at all at high speed. The 597 transducer is mounted within 1" starboard of where to old xducer was due to a different mounting hole pattern and is set at the same depth off the transom.

Any suggestions would be appreciated. Thanks - Carl

 

[greg plunkett]

You must have transducer mounted wrong and is in a groove or something. its a common thing to happen. but not sure since you have mounted it the place.

 

[Humminbird Greg]

You must have the transducer mounted somewhere that is getting air bubbles flowing across the transducer. Try lowering it downwards a little more and/or angling the back end of the transducer down a degree or two, and see if that helps. You want to make small adjustments here and test it, adjust and test again until you get the results you are looking for.





Greg Walters at Humminbird

gwalters at johnsonoutdoors dot com

 

[Carl S]

Greg, I tried lowering it (downward tilt) 1 click down the other day and it did help somewhat, but the screen was still very "snowy" with the same sonar settings and the xducer angle looked pretty severe. Currently there is slight a slight to moderate downward angle. If I lower the mount any further it would be protruding below the transom. Would that be ok for that to happen?

 

[Humminbird Greg]

No Carl, that would not be advisable. Is the transducer mounted on the bottom edge of the transom or is it above the step on the hull (if your PT 185 has a stepped hull)?





Greg Walters at Humminbird

 

[Carl S]

Greg,

The boat does have the stepped hull.

While I was checking this, I seen where I have rivets up the hull that are almost directly inline with the xducer. So I moved the xducer toward the port side. It is now mounted approx. 3" away from where the stepped hull blends into the hull of the boat.

I put a straight edge on the boat hull which is below the stepped pad and extended it toward the xducer. The top of the straight edge meets the center of xducer and I have a slight angle downward.

Hopefully the problem was caused by the rivets, but I will not be able to test it until sometime next week while I'm at Kentucky Lake. I will update when I return.

Thanks for your help Greg.

 

[Carl S]

Problem resolved. Not exactly perfect but a whole lot better.

 

[Humminbird Greg]

Keep working at it Carl. Just make small adjustments when you do. It may take several adjustments to improve on what you have now. If you have the time and material on hand you could try adding a spacer between the transducer and the hull. This will push the transducer backwards and hopefully into less disturbed water. The DC18 I used to run for Humminbird would only get WOT readings (40