You can often buy replacement parts

If your VHF isn’t working, the most likely cause is that the wiring is faulty. Coaxial cables are prone to corrosion and breakages, so this is the first place to look. Companies like Shakespeare Antennas will supply new wires or just new connectors for each end. It’s well worth checking this before buying a new aerial. |If you can, rig up a multimeter and check the connectivity along the wire.