Command Base Compatility Question?

Since the Legacy base is the one supplying track signal, that isn't the issue.  It sounds like you have track signal issues, but not due to drift, the Legacy base is crystal controlled.

So it turns out after some testing, that out of 4 TMCC command bases (how did I happen to get that many?), 3 of them seem to work and run engines just fine. And the one I had on the layout seems out of tune and mostly not responsive. Simple matter to replace it with a good one and all is well once again. Now I may give a try to the re-tuning method developed by Dale Manquen and see if I can get it operable as a spare. It also happens to have the oldest date code of the works; 1998. Yikes! The rest are '02 to '04 date code.

Rod

Another weird discovery: With the base 1 and Legacy base 2 hooked up as above in the OP, and since the cab1L only talks to the Legacy base; not the base1, how come when using the cab1L the red light on the old base 1 flickers on and off, just as if you were using cab1?? I am a bit puzzled by this.

I was able to re-tune the unreliable base 1 I replaced using Dale's technique, no problem. The full range of rotation for L8 where it would operate the whistle was only about 1/4 of a turn. And the position I left it in is about 1/8 turn from where I found it, so it seems it was borderline out of tune. Seems to work fine now.

Rod

The Legacy remote or the CAB1L remote is still triggering TMCC commands on the serial link, so the old TMCC Base is seeing them, hence the flickering light.

Makes sense for sure, just seemed odd at first. I have always considered the flickering red led to be a great confirmation that the base is seeing the handheld, especially since the cab1 and cab1L are "blind" and there is no other way to see if they are putting out a signal.

Rod