There are some people selling steel wire plated with copper for making wire antennas.
Perhaps the most well-known brand of this product, Copperweld, makes at least two kinds of copper-clad wire, copper-clad steel (CCS), and copper-clad aluminum (CCA). On Copperweld's applications page, they write:
CCA is a natural for antennas in a variety of applications such as large ground-based arrays or even ham radios or mobile phones. CCA is applicable to most localized RF transmitters and is being used near radio towers to shield other structures from creating interference.
(note: CCA, the A for aluminum)
Wikipedia on copper-clad aluminum lists applications:
The primary applications of this conductor revolve around weight reduction requirements. These applications include high-quality coils, such as the voice coils in headphones, portable loudspeakers or mobile coils; high frequency coaxial applications; such as RF antennas; CATV distribution cables; and power cables.
The article on copper-clad steel lists nothing about RF applications:
Grounding, union of ground rods to metallic structures, meshes, substations, power installations and lightning arrestors.
To be fair, most of the amateur radio sites I've seen selling anything similar call it simply "copper-clad wire", and don't specify if the core is steel, aluminum, or gold.
It seems to be understood that steel is not a good antenna wire. So, is copper-clad steel a good antenna wire, or no? Why?