There have been a few post on here about the interference issues with the US2 on Minn Kota tm's. I posted about my interference a few months ago and got several ideas. My depth finder is a HB 747C, it was on the boat when I bought it. I have been using lowrances for several years and have had great service out of them. The HB on my boat worked great with the exception of the interference, it made pretty arches:D.

I bought a used HDS5 at a good price recently, before I changed the units out I thought I'd try some things to see if I could help the HB. First I ran a common ground from the tm batteries to the starting battery, No help. Next I tried a ground to the tm in several places, no help. Same with the noise settings, no help. No single thing or combination helped.

I also bought the adapter for the Lowrance to try the US2, I used my Fluke meter to test continuity between the knurled nut on the end of the cable and any of the pins on the other end of the adapter cable for the Lowrance. There was some continuity with two of the pins. On the HB there was none on any pin. My thoughts here was that if there was continunity that a ground to the nut may help. Another thing I noticed was that the Lowrance power cable is shielded, I didn't see any evidence of shielding on the HB cable. Does it make any difference? I don't really know.

I removed the HB and installed the HDS and ran the tm, I saw no evidence of interference at any speed.

Please don't think this a bash on HB, the 747c is a fine unit. I just wanted to try some different things, unfortunately nothing worked, for me any way. You're results may vary : ).