Rene Jensen

Some FBX files contains takes. If they do, Houdini creates takes upon import.
Both these approaches seemed to work well for me using H19.

1. Open Take List and left-button drag some take onto Main. A pop menu allows to pick "Merge take (with override)".
   Simply "Merge take" is not enough as both Main and the unwanted take has values for the same channels.
   
2. In a Textport window: takemerge -f Main <name-of-unwanted take>
   Again it's the -f that does the trick of forcing the merge even though it means overriding Mains animation channels.
   

Once merged, I just delete the unwanted take.