Repairing TV cable

[d000hg]

I've discovered the TV signal is awful in a BTL property and found a suspect joint in the cable hiding in a corner - it's held together with duct tape
I want to try joining this properly before venturing onto the roof or replacing a cable, what do I need? Is TV coaxial cable the same as Sky - I found this part but haven't done anything on a TV cable before:

Amazon.co.uk

 

[Harry Bloomfield]

I found this part but haven't done anything on a TV cable before:

If that fits your coax, it will be fine.

 

[Sureitsoff?]

and to fit the f connectors to the cable watch this first

 

[d000hg]

Thanks both. It must be RG6 because I measured it at ~6mm - looks exactly like in the video posted too.
Looks easy enough, fingers crossed this saves a trip to the roof