Why did radio aerials switch from using metal telescopic tubes to thin cables? And what’s the advantages and disadvantages of each design?

Question

Why did radio aerials switch from using metal telescopic tubes to thin cables? And what’s the advantages and disadvantages of each design?

In: 3

Answer 1

Generally, cost. A thin stiff wire like a car antenna mounted on a fender uses much less metal that a thin hollow tube that retracts into the fender. The wire is more resistant to damage since it flexes instead of bending and snapping off like the hollow tube will.

For larger antennas like house aerials on a roof, having a hollow tube may be preferable since the tube is stiff and will hold itself up, whereas a thin cable or wire requires a guy wire to hold up the floppy end straight. If there is no tree or support structure nearby you need to build and install one which is more expensive than using a self supporting tube.