Here are some passive reflectors used by the BBC. The UHF TV transmitter at Eitshal in the Outer Hebrides is fed from the Rosemarkie transmitter 160km away on a combination of active and passive repeaters on 7GHz. Due to the remote locations in the far North of Scotland there are 2 passive sites to save on the huge costs of running electricity to them and also building and maintaining relay stations.
This passive reflector is at Glenmarksie, 3.6m x 4.8m in size.
These back to back dishes are at Sgurr Marcasaidh and are 3.6m diameter. They linked with waveguide, no active electronics.
The link was built in mid-70s and went active in 1976. 45 years ago this was some serious RF linking!
Pictures © 1977 BBC Engineering.