Shifting and Scaling Heaviside FT in Mathematica

[Arkenoid]

Hi all,

I am having trouble with computing the Fourier Transform of a shifted
AND scaled Heaviside function.

Basically I can get:
FourierTransform[HeavisidePi[(x + a)], x, \[Xi]] =
(E^(-I a \[Xi]) Sinc[\[Xi]/2])/Sqrt[2 \[Pi]]

or
FourierTransform[HeavisidePi[(x/b)], x, \[Xi]] =
(Abs[b] Sinc[(b \[Xi])/2])/Sqrt[2 \[Pi]]

but when I combine [(x + a)/ b] i get nothing!
Any clue??

Thank you!