Topic: How to eliminate sonar noise?

[erocks4u]

Hello all, I am using two 1198’s one on the console with and HDSI mounted on the transom, the other mounted on the bow with an HDSI mounted on the trolling motor. I initially thought the noise was interference from something else. But I found that if I shut the sonar off on one of the units the noise was gone. It doesn’t matter which one I shut off as both are experiencing this problem. The attached picture is showing the noise when on and how it clears when off. I tried the noise filters (only minimal help), tried setting one unit to 83 and the other to 200 but then then I loose detail. As you can see it is affecting regular sonar and side and down imaging also.
I am open to suggestions, they are joined using the Ethernet and I could use one transducer, but I only fish in the river and like the fact that the front of the boat can sit on the top of the ridge and the back can sit deeper giving me a better overall idea of where the fish are sitting.
Thanks in advance for your feedback.

[TroyBoy30]

if it only occurs when the sonar is on on both units, its cross talk.  you should always cut sonoar off on the unit you are not using at the moment.  i cut sonar off on the bow before i pull up the trolling motor.  then cut sonar on when i get to the console.  all you have to do it hit the power button and cut sonar off

[erocks4u]

Thanks for the reply, but there is two of us fishing one in the front and one in the back, it also allows me to see how much of a drop there is between front and back of the boat.

[Humminbird_Greg]

Even with the Noise Filter menu set to its max (High 3) setting it did not help?
Your only option may be to share a transducer or turn one off than.

[erocks4u]

Thanks Greg,
     Noise filter made minimal difference. looks like i will be sharing the front transducer. I still have to try adjusting the angle of the rear transducer to see if that makes a difference.

Hope you enjoyed your time away.

[TroyBoy30]

if you have to have them on together, put one on 83 and one on 200

[Humminbird_Greg]

That won’t help TroyBoy as both units will still be transmitting and receiving on the 200kHz frequency.  Even if the Sonar Beam menu is set to the 200kHz setting, the unit is still using the 200kHz frequency to determine water depth.

[TroyBoy30]

got ya.  didnt know that

i simply cut sonar off when i move to the other unit.  I always fish alone and if i dont the guy in the back dont need to see nothing lol

[LocDown]

I have had this problem also but I ended up just removing the front unit before investing in anymore time. Have you tried maybe RF chokes?

[erocks4u]

I have had this problem also but I ended up just removing the front unit before investing in anymore time. Have you tried maybe RF chokes?

Didn't think of trying RF, will they help for sonar noise, maybe worth a try.

[ezfishn]

I've had the same problem only I have the 1198 on the TM and a 998HDSI at console.  I've had no luck with the noise filter settings on eliminating the crosstalk.  I also always have a person in the back of boat.  I think I'm going to try connecting the front unit to transom xducer.  That way I don't have to power off the front unit everytime I raise the TM. 

[jimmythegreek]

how deep of a river are you fishing?  i fish a fairly deep lake and what I do when i get to deeper water and experience crosstalk I turn off the transom unit's SI by going into transducer type and choose dual beam.  I have the rear one with a Y cable and a 2D ducer next to it and I have minimal interference from the other unit, its just a blip every few seconds, can barely tell its there

[ezfishn]

how deep of a river are you fishing?  i fish a fairly deep lake and what I do when i get to deeper water and experience crosstalk I turn off the transom unit's SI by going into transducer type and choose dual beam.  I have the rear one with a Y cable and a 2D ducer next to it and I have minimal interference from the other unit, its just a blip every few seconds, can barely tell its there

If you were asking me....I normally fish in a reservoir that is deep but fishing 40ft or less.  Not real sure about the xducer setting working.  With the Y-cable you will always be using the 2d xducer and not the 2D from the SI xducer.  I have a nitro z8 and the hi-def xducer is on the jacking plate and 2d xducer is in the bilge area for the console unit.  I notice most of the crosstalk in SI and 2D images when I'm using the TM related unit.

[Humminbird_Greg]

ezfishn,
Why not Ethernet connect your 1198c Si and 998c HD Si units and just select to use either the trolling motor mounted or transom (and bilge) mounted transducer for both units?

You can also try manually selecting a different Lower Range setting for the depth range.  This will change the ping speed of the unit and may be enough to help.

RF chokes should not help with sonar-to-sonar interference.

[ezfishn]

ezfishn,
Why not Ethernet connect your 1198c Si and 998c HD Si units and just select to use either the trolling motor mounted or transom (and bilge) mounted transducer for both units?

You can also try manually selecting a different Lower Range setting for the depth range.  This will change the ping speed of the unit and may be enough to help.

RF chokes should not help with sonar-to-sonar interference.

Thanks Greg...they are Ethernet connected.  Only have had a few hours on the water with them.  Which range setting are you referring to?  If that doesn't work then I can select the same transducer

[Humminbird_Greg]

The "Lower Range" menu setting.  This should be one of the X-Press menus when you are looking at one of the 2D type Sonar Views.