Layout background - running with both DCS w/wifi and Legacy; two lower loops, a yard and one upper loop; power provided by two Z4000s using all four handles each on a separate TIU channel; 990 ground connected to output side of TIU (Rev L) with all black terminals tied together.
I was having problems with some legacy engines receiving consistent commands, especially adjusting smoke levels. I purchased the Legacy buffer/signal booster and hooked up. A quick measurement shows 1.8v base out and 5.8v boost out. With the booster in place things got much better but I still experience a couple of areas that have inconsistent commands. I have thoroughly cleaned the track a couple of times with no real change in performance. The problem areas seem to be where my upper track is running parallel and directly above lower.
I'm thinking my next step would be to add a ground plane wire attached to upper level. Since this will require a decent effort wanted to get feedback if this seems like a reasonable next step or if there are other things I might try. Also, if I do connect a ground plane wire, can I use the same earth ground point as the Legacy Buffer/Signal Booster?