Well, there are a few reasons why.
- Water ingress and damage to the antenna or cable
- Frequency changes from the transmitter mast
- Cable degradation
- Amplifier Fault
- A fault with the television
Water ingress or damage to the antenna or cable
- The original aerial is of poor quality and design. Therefore, it isn’t up to taking the punishment it gets from being out in all weathers. The aerial then allows water to gradually get within it.
- Over years the waterproofing housing where the dipole is located fails and allows water to penetrate it. This tends to happen if an aerial is decades old.
The Transmitter changed its frequencies
This is probably the best reason for an aerial to stop working as it is an easy fix that most people can do themselves.
Coaxial cable degradation
Fault within an amplifier
A fault with the TV
Conclusion
So, aerials can stop working, but it isn’t always the same reason and, in some cases, it isn’t even the aerial itself. For the best way to find out if the aerial is faulty, an experienced local aerials engineer is the best bet.