Trying to recall TV from my childhood

I’m trying really hard to recall fragments of TV shows I watched when I was a child.

In particular right now, a show that I think routinely involved time-travel. I think it was British though I may be wrong. Had a time machine with a sort of transporter pad and a robot head face thing to one side. Looked like this I think:

And I think the time-travelling kids had some sort of return-buttons on their belt-buckles?

(EDIT: Might have been located in a medieval tower, which is where the machine sent them back to? Think it was destroyed at some point. Recall it laying all smashed up like the tower had collapsed on it.)

Pretty sure this was well before The Girl From Tomorrow. Possibly Pink Windmill/Puddle Lane era? (that’d be 1984-1988) That’d be the same period at that schools educational drama about the ghost of a knight that lived in a tower, right?

It might have been the same show that had a bus that turned into an airship? I remember one with a propeller at the back, lots of bicycle parts used.

Same era as a film I used to re-rent at the video rental place up the road (along with the Claymation Adventures of Mark Twain) that had a flying tandem bicycle in it with flapping wings (It wasn’t in black and white, but was very grey, so pretty sure it was filmed in 70s/early-80s England that one).


Another one, another Australian import I think, had something to do with a psychedelic clock in a shopping centre and some small glass balls that were missing from it.