I run a Lowrance unit with 200 mhz on one side, and a HB 797 on the other with minimal interference; more noticeable when on SI, actually. I set the noise filter on the HB to low and it usually eliminates the interference. If I happen to need to eliminate all interference temporarily, I just stop the chart on the Lowrance until I need it again. Adjusting the ping rate on the Lowrance will help, too.