The term "distribution amplifier" covers a lot of territory. Generally speaking, these amplifiers:
- Utilized vacuum-tube technology.
- Were designed for indoor installation.
- Required 115-volt 60-Hz operating power.
- Were constructed on steel or aluminum chassis.
- Were fitted with some sort of metal cover to provide mechanical (but not weather or dust) protection.
The earliest distribution amplifiers were designed for home use. They were fitted with 300-ohm input and output connectors for use with 300-ohm dipole antennas and twinlead interior wiring.
Later versions were fitted with coaxial connectors for use with coaxial interior wiring in homes and MDUs. As the MDU market grew, manufacturers developed specialized distribution amplifiers with higher output power levels to feed multiple outlets. They could be connected to receive signals from a rooftop antenna, a cable TV drop, or master antenna system.
As the cable television industry grew, some cable operators began using distribution amplifiers as line amplifiers, often installed in pole-mounted weather-resistant cabinets. One such installation was featured on the cover of the March 1964 issue of TV & Communications magazine.