[Elecraft] KAT3 ATU question

[John Sweeney]

Question regarding the KAT3, internal ATU in K3.  This is not clear to me in
the  product description. 

Does the KAT3 retune along with the VFO frequency, once memories are stored,
without RF sent through it?   Or, is Tune with transmit RF required for the
ATU to sense the frequency and tune for best match?       I believe the
KAT500 adjusts based on rx frequency, but not sure about the KAT3.  

Thanks

John , N3WT