The Model KMA4040 is an RF power booster amplifier for use with tactical VHF transceivers in the band 30 to 40 MHz and with output powers of 1 to 5 W similar to the AN/PRC-117F. The booster amplifier is comprised of an ALC controlled power amplifier, VSWR monitor with power fold back, TTL logic Keying circuitry, and an internally regulated dc to dc power supply system. The booster amplifier incorporates coaxial relays to provide transmit to receive switching and is keyed by a TTL logic input signal. Cooling of the unit includes internal heat sinking and fans with over-temperature protection. The booster is comprised of a rugged splash-proof housing with front-mounted RF input and output connections, an on/off the power switch, and DC power/Logic connections.