Lionel CrewTalk Question

Press and hold the start up button on the legacy remote. 

And when you're done, you can press and hold the engine shut-down button for additional talk.

Also, I don't have the remote in front of me, but I believe if you press Aux1 before you press either crew or tower talk button you will get "negative" talk, i.e., "don't go" - "hold", etc.  instead of "positive" talk, i.e., "clear to go", etc.

Finally, I believe if you hold down Aux 1 after engine start for about 2-3 seconds until you hear the bell and then let go, you will get automatic talk and sounds throughout your run.   

LOL.  I knew it had to be something simple.  Its easy to skip over something in the Legacy manual.