I received a request for help from a customer in Sinton Green near Worcester who was complaining that one of her TVs had no signal.
On arrival it was clear to see the problem without the need of any test equipment or ladders.
Any outside TV coax that's been cut and then repaired using PVC tape WILL FAIL eventually, guaranteed!
I've lost count as to how many I've seen over the years but this is one of the most common DIY mistakes I see.
This TV coax had been accidentally cut by a gardener while pruning the pyracantha two feet from the ground it was then re-joined using coax plugs and a coupler and then bound tightly with yellow PVC tape.
This very common DIY repair will normally work just fine for perhaps up to a year or two but rain water will ALWAYS find it's way in, so it's just a matter of time before the constant moisture and inevitable corrosion will destroy the joints ability to pass a TV signal.
I would guess that a joint that's left open to the elements without using PVC tape could last longer than one that is covered in tape.
One thing is for sure, PVC tape will NEVER stop rain water from entering, no matter how tightly bound the tape may be.
In this case there was still an excellent signal from the coax entering the joint but little or no signal at all passing through the badly corroded connection so it was decided to re-join rather than replace the coax back to the Aerial.
Using the superior F type plugs rather than standard TV coax plugs (as seen in the lower of the two images above) and then wrapping this with water proofing, amalgamating, rubberised tape will ensure that no water can enter, giving the joint a life expectancy similar to the coax that it's connecting.
Another example I will never forget despite it being almost 10 years ago was on a cold, snowy winters day when I received a call from a well known BBC TV presenter who was convinced that his Aerial must have moved in the wind as he was not getting a TV signal and had lost all TV channels.
Arriving at his home and noticing that the Aerial was mounted on his garage I quickly assessed it to be unlikely that any movement of the Aerial would have had such a dramatic effect on a TV so I questioned him with regards to the unusual coax cable run which ran for some distance underground down the garden before reaching the TV in his lounge.
After a short period of time it became clear that my customer was getting a little agitated and upset with my questioning relating to the TV coax's route and direction of travel down the garden, making several strong suggestions that I should just get on with the job and stop wasting his valuable time with questions unrelated to what he believed to be a misaligned Aerial.
On asking the question " Has the coax cable ever been joined? " it was with some reluctance that he then admitted to having once accidentally put a spade in a little too deep and it being severed, but he did assure me, in no uncertain terms that it could not possibly be the cause of his reception problem as he had wrapped it tightly with PVC tape and covered it with plastic bags before re-planting it back underground and it had worked perfectly for years. Of course, on hearing this I immediately knew what the problem was but convincing my customer was still anything but easy.
With the snow now falling and several holes dug in the garden (he couldn't remember exactly where the join was) he was anything but happy. As you can guess, the joint was eventually found, soaking wet and corroded beyond recognition. I wasted not a moment longer, repairing it as described above which of course immediately restored his TV signal / TV pictures.