Splicing cables in general is problematic; mainly because even waterproofing does not work "perfectly" because of moisture in the air is already in the new cable when you put it in. Every few years, it will get into the cable and cause the picture to go out. I have had to fix many, if not all I have tried myself; and find others too many times to recommend it. All the posts here in this thread, however, are the way to make one last for a year or more; but sooner or later (depending how many times your sprinklers soak where it is at) it will fail. Cable is 1.50-3.00 per foot; time and aggrevations of the problems that will haunt you may be more trouble than it is worth (and you won't have a splice causing any troubles anymore). I liked keeping my splices above the ground so they never got "held in moisture" and they worked the longest for me; but they always "failed" after a year or so; and nobody will gaurantee cable from waters ingress, let alone a splice in one. Besides, soon Obamacare will add dentistry to his plan; and even dentists will be "assured" of payments. And on your new 50 foot screen; why see any problems dtv has compared to original broadcasts!