Caracal/Garmin/3-1 interference

[WjColdWater]

This has been a on going issue and I’m looking for a comparison for further troubleshooting.
-2021 Caracal Atlas J Plate
-Garmin Echomap Ultra 106sv at helm/126sv bow
-GT36UHD Atlas mounted/GT8HW thru hull
-Garmin Force with 3-1 transducer
-Transducer saver mount on the starboard side of Atlas
-Mercury 225 4s
#1 issue surface straight line interference starboard side

#Troubleshooting to date:
-Boat level position in the water with average load established


-Weight added to simulate average load fuel and gear

#Adjustments
-Transducer leveled front to back and port to starboard at 3mph

#Water test with these adjustments cleaned up the fuze on the starboard surface but no change on the port side.
#Adjustment 2
-Added a 1”x1” tube shim to lower Transducer to give additional clearance from the atlas plate

#Water test after shimmed same results still port side surface interference overall image very good, but the surface straight line interference is very annoying. I have cut power off accessories to test, plate and trim adjustments, speed and unit sensitivity adjustments and no difference. I’m thinking the J plate or my transducer position in relation to the plate is the problem. Looking for any input that may help with troubleshooting this issue.
TIA Wayne

[BASStex1988]

Truthfully I think the issue is transducer shield. I’ve had the same issue no matter what I do with that transducer

[MonteSS]

Well something is blocking left side.

[WjColdWater]

Update on my straight line interference issue. After some research I finally eliminated the port side straight line interference on SV. Garmin was little help, but was very responsive on my request for help. They did hint that ferrous metals (jack plate aluminum) or RF interference could effect SV returns. I also had help from mechanical engineer and member(mikesxpress) on adding a hole shot plate as possible solution. I designed and fabricated a aluminum splash plate for my Atlas hydraulic Jack plate for starters. Atlas makes splash plates for all their jack plates except BassCat. The goal was to eliminate kick back from the Atlas by closing the jack plate voids. A second possible improvement would be a better hole shot and set down with the modification. After several testing days and further modifications I achieved my goal.
Splash plate pattern developed.



Proto type plate finish file fitting with 1/16” clearance from transom glass and transom light. 1/8” clearance between the splash plate and Atlas vertical hydraulic plate.


Testing after installing raw aluminum plate didn’t resolve straight line interference. Last modification coating splash plate and the lower Atlas mounting ears with primer and rubber. This eliminated straight line surface interference on my SV completely. I also coated the Transducer Saver L bracket and mount with rubber as well.
Jack plate ears coated and splash plate.


Transducer Saver mount coated.

Finished install.


Have tested extensively and very happy with my SI and splash plate performance. A few screen shots after modifications transferred from the Garmin’s to my iPad. Settings dialed in and plenty happy with Garmin SV and DV. And that annoying surface straight line interference is history. I believe I also have a better hole shot after the modification.



I did reach out to T-H Marine on my plate idea still waiting for a e-mail response. I also talked to Garmin on my testing results so they may help others. Garmin was great on their responses on my requests for help.

[apdriver]

Wow, nice work and a lot of testing and work went into this solution looks like. What spray rubber product did you end up using?

[WjColdWater]

Wow, nice work and a lot of testing and work went into this solution looks like. What spray rubber product did you end up using?

Thanks! Yes this was a month long process and I was very consistent with the testing. Aluminum plate was sanded and cleaned with acetone then a coat of Rustoleum aluminum primer. Finish surface two coats of Flexseal spray rubber. Let all cure 48 hrs before testing. Coating seems durable just finished a multi day trip to MN. Spent a lot of time scouting with SV and images were excellent.

[printman71]

You are much more dedicated to getting it "right" than I am. Kudos to you for that.

[WjColdWater]

You are much more dedicated to getting it "right" than I am. Kudos to you for that.

Thank you!

[mikesxpress]

Excellent job Wayne!
And extensive details on what was done to correct the issues. That's exactly what these BBC forums are for. Helping others.

[catdude28]

Wow. You are certainly a determined individual. Great job.
I would have traded the boat

[Louie]

My 2021 eyra did the same thing, same transducer set up with a garmin 12 at the helm, went with a 1.5" drop from transducer shield and it got rid of 90% of the left side funk. Bass cat doesn't ever install the drop spacers because they dont want us knocking off transducers on stumps I guess.

Nice work btw! The hole shot plate you made looks awsome!

[WjColdWater]

Thanks Mike for the advice!

[WjColdWater]

Excellent job Wayne!
And extensive details on what was done to correct the issues. That's exactly what these BBC forums are for. Helping others.

Thanks Mike for your help!

[WjColdWater]

My 2021 eyra did the same thing, same transducer set up with a garmin 12 at the helm, went with a 1.5" drop from transducer shield and it got rid of 90% of the left side funk. Bass cat doesn't ever install the drop spacers because they dont want us knocking off transducers on stumps I guess.

Nice work btw! The hole shot plate you made looks awsome!

Thanks Louie! Trade skills came in handy.