Series AR amplifiers are rack-mountable units which incorporate the Series AM amplifier in a cabinet containing a built-in universal AC power supply (for models up to 100 watts). Models are available for operation at frequencies from 1 MHz to 2 GHz and output power from 10 to 250 W. They are forced-air cooled by blowers built into the mechanical package. AR models are also available with an optional IEEE BUS for remote control and monitoring (ARD version).