Amplifier Research 2500L

The Amplifier Research 2500L is a self-contained, air-cooled solid-state RF amplifier delivering 2500 W continuous-wave output across 10 kHz to 220 MHz with minimum 64 dB gain. This broadband unit operates without damage across any load impedance, tolerates 100% of rated power without foldback, and faithfully reproduces AM, FM, and pulse modulation. Front-panel controls govern power, standby, operate, and output level adjustment; rear connectors support Type N RF input, 7/16 DIN RF output, and optional forward/reverse power sampling. Remote operation via TTL, IEEE-488, Ethernet, USB, GPIB, fiber-optic serial, or RS-232 enables laboratory integration. Crowbar protection safeguards internal components from arcing damage. Input impedance is 50 Ω at 1.5:1 VSWR maximum; input power to rated output is 1.0 mW maximum. Pulse output reaches 4000 W. The 2500L accommodates continuous gain adjustment across a minimum 20 dB range and maintains ±3.0 dB flatness across the operating band, reduced to ±1.0 dB with internal leveling. Rise and fall times measure 10 ns maximum. Harmonic distortion does not exceed −20 dBc at 1800 W output. Frequency-specific variants support narrower bands; model 2500LM8 operates 1 MHz to 220 MHz. Output at 1 dB compression point is 1750 W, with derating above 100 MHz on certain configurations. Reflected power limiting engages above specified mismatch ratios to protect circuitry.