Show about three mystery solving teenagers 1970s?

My memory of this show is very hazy. It was probably on television in the late 1970s or VERY early 1980s. It was about three teenagerish crime solvers. One was a boy with brown hair, the other two were female, one with straight blonde hair the other with wavy brown hair. All I really remember about the show was that the three of them seemed to plan out most of there adventure from either a basement of an old building whose interior looked like a basement. The only other memory that I have of the show was an episode were they trapped on some kind of a roller coaster that appeared to be going through outer space (sounds vaguely like a scene from The Black Hole doesn't it?) Now, I saw this show a few times back in the late 70s or very early 80s. So, I am certain of its existence. However, my memories may have warped over time to include elements from other sources like The Black Hole which came out in 1979.