The early system used an antenna known as a hogtrough.
Systems with high data rates may even use a directional antenna, if required.
This technology can use multiple antennas to target one or more sources to increase speed.
However, using a single antenna only gives a direction.
In most cities, subchannels must be received using an antenna.
Smaller systems may use a broadband antenna to share several channels.
In the late 1960s traffic radars began being produced which used a single antenna.
The system used a smart antenna to improve reception in fringe areas.
Phased array is a different technology for using multiple antennas.
Type 33 was still another 10-cm set; this one used separate round-horn antennas.