Need help identifying a particular classic serial

I've been trying with the help of wikipedia to identify the first Doctor Who episode I ever saw, but TBH, I'm baffled. I'm reasonably certain it was a Pertwee story, but could've been Tom Baker. It's definitely one of those two. I don't recall the plot or the main aliens, all I can definitely remember is that there was some sort of military force running around the usual quarry in Wales wearing black uniforms with red trim.

Does this ring a bell with anyone? As I said, pretty sure it's Pertwee, but reading the episode guides I've been able to find hasn't turned it up.

COLONY IN SPACE

Took me thirty seconds to confirm!

You are thinking of the IMC miners.

It was also Jo Grants first journey in the TARDIS

Whoosier Whovian wrote:

COLONY IN SPACE

Took me thirty seconds to confirm!

You are thinking of the IMC miners.

It was also Jo Grants first journey in the TARDIS

Cheers! That's the one!

And one I am waiting patiently for to arrive on DVD. I have a fondness since I read the Pinnacle novelization years before we were able to see it in glorious color on PBS.

Whoosier Whovian wrote:

And one I am waiting patiently for to arrive on DVD. I have a fondness since I read the Pinnacle novelization years before we were able to see it in glorious color on PBS.

I'll be buying it as soon as it does become available. Any tips on where to track a release schedule?

this thread might help:

https://whona.forumotion.com/t5640-final-dvd-schedule


Unfortunately, it looks like it'll be one of the last releases

Another great resource, which has nothing to do with sales, merely an informational site;

http://home.comcast.net/~smanfred/

I believe I read in DWM that it is scheduled for release on 2012

Thank you all!