Humminbird problems

Anybody else having this problem?

I am running a 997SI on the console and a 787 up front. I have been having problems with the 997 reading 1000+ ft more than it reads the actual depth of (3-25ft). I sent an email to Humminbird and their reply said,

“The 997 and the 787 operate on the same frequency, therefore if they are both on at the same time they tend to interfere causing the depth to be off. It does not matter the location of the transducer you will need to either operate one unit at the time or shut the down sonar off on the 997 to keep the units from interferring.”

How can they advertise these units to work together via interlink and they interfere with each other?

What are you guys running with no problems? I might have to get rid of the 787?

If I am thinking correctly, their interlink is both units sharing one transducer. You will run into this crosstalk interference with any unit you buy that has similar frequencies (i.e., if you bought a lowrance and it had a similar frequecy, it would do the same.) Can be depth related, which with my lowrance units, I will get cross talk if deeper than 15 feet. If you can not change the frequency of one unit, then turning one unit off will solve your problem.

You are using your 787 up front. Just set it’s frequency to 83Hz and leave the big SI transducer in back at 200Hz. Try that and see what happens.

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If I am thinking correctly, their interlink is both units sharing one transducer.

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Interlink only shares waypoints, routes and potential GPS Reciever, has nothing to do with transducers for 2D or side Imaging.

I would try running them at different frequencies and see what happens as suggested.

I run a 997 off the transom and a 788 off the bow and do not have cross talk interference issues that I know about. Next time out I will have to do some more homework and try turning one off and see if I have difference. Most of the time I am running my 997 with 200khz and my 788 with 80 unless drop shotting, then I run both at 200khz.

Yes the Interlink only shares waypoints and similar data, not trnsducers or maps.

I have 997 on the das and a 1157 on the bow and get interference at depths over 35′ only. I coluld play with frequency but I just turn the one off that I am not using

Mybe do a hard reset and start over with your settings, maybe something just isnt adjusted right?

Thanks guys! I’ll give those ideas a try.

I run the same as Moreyes but swapped and do not have problems. I do however get crazy interference if within about 60′ of any other boat. Not sure what electronics they have had but both units go crazy. Thats fine thought since I hate fishing close to other people!

Wonder if transducer tilt affects this. The one on the transom has to be tilted forward just a hair to keep the water flow over it clean at higher speeds, so if you have the one on the TM straight down or the shaft is bent back a bit the cones could be overlapping.
In Doc’s classes he suggests a bit forward on the TM transducer, I figure a shim of some kind, so you can swing it around to see if some thing is left, right, or ahead but this would also help to keep the cones from over lapping as bad.

WarrenMN

No matter what frequency the unit is set to it will always ping the 200 khz frequency. Humminbird uses the 200khz for the depth reading because it is the smaller cone angle. Depending on how far apart the transducers are, you shouldn’t see any crosstalk unless you are in about 25′ of water or deeper. The closer the transducers are the shallower this happens. I have the same setup on my boat, an 18′ model, and do get some interference at deeper depths but it is still usable, just gets cluttered a little. Using the built in noise filters under the sonar menu help some