Well it was too good to be true. I tried some cleaning paste like used to clean copper connections for soldering or splicing. At first it looked like I had a good signal, but it was not to be. I put the HB385 back on and it has the same problem so I am down to either the transducer of the adapter cable. The 385 was working fine when I took it off to use the Helix so something has changed since then.
I will contact MK and see if they will swap out the cable and hope that is it. Sure don't want the hassle of trying to fix/replace the built in transducer on the TM.