It's a bit hard for me to tell, exactly.
If we are going by UK airdates, then it was sometime between Pertwee's first season and the second, so somewhere between
Inferno &
Terror of the Autons. Did they re-run Doctor Who over there in 1970 after the first season ended? If so it was probably a repeat of the 6th or 7th season.
Going by Australian airdates is even more difficult, as I don't have a list of them for ABC in 1970. I can tell you that during that year, the ABC was repeating Troughton's 5th & 6th Seasons (I don't think season 7 hit our shores until 1972/73). I'd like to think it was something like
Tomb of the Cybermen or
Fury from the Deep, but it was probably
The Space Pirates knowing my luck.
Of course I was too young to even know the show then. My first memory of Doctor Who was
Spearhead from Space. I can tell you that it scared the absolute bejeezus out of me (seriously!).
Starkers said:
Hmm unfortunately I was born between seasons. Somewhere between Inferno and the Terror of the Autons!
The Badger said:
Inferno episode 7 is nearest to my birthday. Christ I feel old.
So we are roughly the same age!