Thread: 997 & 957 interference

I've read a lot that you guys have posted about getting feedback on your units but I still can't figure out my problem. I've got a 997 at the steering wheel and a 957 up front.....if I use the 83khz transducer I get blue lines in my graphs....the only thing they have in common is that they come off the same battery...one is wired on the left side of the boat and one on the right.....any thoughts on what I might could check????

Sounds like sonar interference to me. Even though you may have the Beam Select menu set to the 83kHz setting, the unit is still transmitting and receiving at the same 200kHz frequency that the other unit is. About the only things you can do to minimize this is:
- Make sure you are running the most current software. Our Engineers keep striving to lessen this type of sonar interference so running the latest and greatest software is your best option.
- Try turning on and up the Noise Filter menu on the unit that is showing the interference.
- Try manually setting the Lower Range menu to a different setting that the other unit is using. In this way you will be varying the transmit rate which can help as well.
- Move one of the transducers farther away from the other. The farther away they are from each other the less likely that the sonar beam transmitted from one will overlap the transducer of the other unit. I have also heard where some have angled or aimed the transducer away from each other slightly and had good results with this.
- Power one unit off or turn off the sonar in it.
I would work down the list trying each one at a time. Fishing in deeper/shallower water or over a different bottom type will also lessen or increase the chances of sonar interference or sonar cross-talk from happening.

I had a similar problem between my 997 and 917----I've started turning my 997 off when I'm fishing the bow. Took care of the problem for the most part.

Is it true that the 200kHz frequency is always on when unit is on?, I mean you may not have it on display but it comes on when unit is on. The others are only on when you are in their display mode. Plse correct me if wrong..........Gosh I would so like to have a 957/8? on bow next year..

Yes, as long as the Sonar is on (Si sonar or the 83kHz or 50kHz 2D sonar) the 200kHz is pinging away.

That's because 200Khz is the most common used frequency. If it was turned off, the phones would ring off the wall.