It's a good story. The radio telescope bit was a bit weird. The free Scarman brother invented it early but it was never developed why/how or did I miss something?
No, he just has:
DOCTOR: Interesting contraption.
LAURENCE: Kindly leave that alone, sir. That apparatus is delicately adjusted, and furthermore is a receiver containing highly dangerous electrical current.
DOCTOR: Yes, so I see. What year is this?
LAURENCE: What year?
DOCTOR: It's a simple enough question, surely.
LAURENCE: Are you telling me you don't know what
DOCTOR: If I knew I wouldn't ask. Don't be obtuse, man.
LAURENCE: Nineteen hundred and eleven.
DOCTOR: Ah. Splendid. An excellent year. One of my favourites. Yes. I really must congratulate you, Mister Scarman.
LAURENCE: On what?
DOCTOR: Inventing the radio telescope forty years early.
LAURENCE: That, sir, is a Marconiscope. It's purpose…
DOCTOR: Is to receive radio emissions from the stars.
LAURENCE: How could you possibly know that?
DOCTOR: Well, you see, Mister Scarman, I have the advantage of being slightly ahead of you. Sometimes behind you, but normally ahead of you.
LAURENCE: I see.
DOCTOR: I'm sure you don't, but it's very nice of you to try. Now, why don't you show me how this gadget works?
LAURENCE: Do you mean you want me to
DOCTOR: Please. Just a little demonstration.
(Scarman flicks three switches then pulls down a lever, which connects the electrical circuit with a spark and cloud of smoke. The wheel begins to spin.)
DOCTOR: Amazing. That's really amazing.
(Scarman disconnects the power but the wheel continues to spin faster and faster.)
LAURENCE: I can't switch it off!
(A large diode explodes and the machine finally dies.)
SARAH: Oh, very impressive.
LAURENCE: It's never done that before.
DOCTOR: Fascinating. A regular pattern repeated over and over again.
SARAH: Like an SOS?
DOCTOR: I wonder. Where was your aerial tuned?
LAURENCE: Mars. Why?
DOCTOR: I just thought I'd verify the signal.
(The Doctor takes a small radio from his pocket and extends the aerial.)
LAURENCE: What's that you have, Doctor.
DOCTOR: Well, in principle it's exactly the same as the gadget you've invented, only less cumbersome. Yes, it is the same signal. Obviously automatic. Well, if it's a message, it shouldn't be difficult to decipher. They'd want to make it easy.
(The Doctor starts to make notes in his notebook.)
LAURENCE: Who would?
SARAH: Whoever transmitted it.