That tape is also called self-amalgamating tape, if I'm not mistaken.
So you can look for that term on the internet shopping pages, as well.
BTW I always take care, that my cables at the dish first go UP for a short distance, before going to the ground.
That way I hope a rain water invasion at the F-plug can never get far in the cable (but beware of the extra capillary effects!).
Greetz,
A33