Utilization of push-pull MOSFET circuitry lowers distortion, improves stability and allows operation into any load impedance without damage. The Amplifier Research 25A250A, when used with an RF sweep generator, will provide a minimum of 25 watts of swept power. The Amplifier Research 25A250A includes a front panel control which permits the operator to conveniently set the amplifier's desired output level. Housed in a stylish contemporary enclosure, the Amplifier Research 25A250A provides readily available RF power for typical applications such as RF susceptibility testing, antenna and component testing, watt meter calibration, and use as a driver for higher power amplifiers. The Amplifier Research 25A250A utilizes a switching power supply with universal and autoranging input which will automatically accept from 90 to 135 VAC or from 180 to 270 VAC at 47 to 63 Hz.