How did Jack know what The Master had turned the TARDIS into?

in the episode The Sound of Drums. when Martha, Jack and The Doctor find the TARDIS, after Martha comments that the TADIS sounds like it was sick.

The Doctor: It can't be. No no no no no. It can't be.

Martha: Doctor, what is it?

The Doctor: He's cannibalized the TARDIS.

Jack: Is this what I think it is?

The Doctor: It's a paradox machine.

It sounds like Jack had encountered a Paradox Machine before as he is about to identify it. i am wondering if it's apart of a Time Agent's Basic Training to know what and how to identify a Paradox Machine or has he encountered one before? (as i haven't seen a lot of Torchwood thanks to stupid TV cutting it off whenever it feels like)