I am using the Legacy base with Cab 2 (also Cab 1L) and all is working well.
I have the "Y" DBL cable attached to the Legacy base which provides the following:
1 - Serial data and COM wire connected to a TMCC AMC (6-14183) Accessory Motor Controller that I use to control my DC turntable motor.
2 - Using a DB9 RS232 Serial Female Adapter, I attached a wire to Pin 5 to provide a connection for running a ground plane wire under my upper level tracks and also over my three SC-2s. This eliminated signal problems I was having.
I have three SC-2s which get their signal from the Legacy base.
My guess is that I will need to replace the TMCC AMC (6-14183) with an LCS AMC2 Accessory Motor Controller. According to the instruction booklet, it can be programmed to run a DC motor.
I do not know where I will be able to connect the wire for the ground plane issues. Maybe the ground lug from an outlet would work just as well. My outlets do not have a screw in the center, so that may be a bit tricky.
While there is plenty of time to sort all of this out since the Cab3 base does not yet exist, I wanted to raise these issues as I'm sure others have similar arrangements that are also working well with the Legacy System in place.
I'm hoping to enjoy the advantages of running trains with the new Base3 without having to solve these transition matters after discovering them later.
Moderators: Perhaps a dedicated thread can be started where questions about the new Cab3 / Base3 can be posted.
Thanks!