Thread: 2 Sonar/FF units grounding?

Are you sure he wasn't grounding the TM? That will help eliminate interference from it. I run 2 Lowrances and get interference when I get in 20ft or more water. Its just the nature of the beasts. The only way around it is to turn one off or run 2 with different frequencies.

Originally Posted by BUZZARD464

I was skimming through the bass home page and noticed an article where a guy was using 2 sonar/ff units at the same time and having interference. A guy mentioned something about grounding a unit to the battery. Has anyone had any experience with this?

When two units are used, they will often interfere with each other. About the only thing you can do is move the transducers apart. No grounding will help, because they are just seeing each other's signals. If a unit has interference from a TM, then connecting the TM ground to the cranking battery ground can help, or adding a ground to the TM housing might help as well.

Yes that was it, he was grounding the TM. Thanks guys.

Canepole can tell you.

Any time you use multi elec units of any kind a common ground is highly recommended. I don't know about your problem being fixed by the ground though.

If you have 2 transom mount transducers with 20 degree cone,and if you mount them 4 feet apart, you can probably run safely in water up to 5 feet deep without crosstalk.

However, if one is 50khz, and the other is 200khz, you might get by with it. This would depend on the tx power of the units. Remember, 200khz is the 4th fundamental frequency of 50 khz. Power can be damning.

I could be wrong.

Tom