The Icom AT-140 is a heavy-duty automatic antenna tuner manufactured by Icom Inc. in Japan. Designed as the primary antenna coupler for Icom’s commercial marine HF SSB transceivers—including the IC-M803, IC-M802, IC-M710, IC-M700PRO, and IC-78—the AT-140 automatically matches the transceiver output to long-wire or fiberglass whip antennas across the 1.6 MHz to 30 MHz high-frequency spectrum.

Housed in a rugged, weather-resistant acrylic enclosure with rubber sealing gaskets, the AT-140 is built for outdoor deck or lazarette installation near the base of the antenna. Controlled directly by the connected transceiver via a standard 4-pin control cable, the unit performs automatic low-power impedance matching in 2 to 3 seconds and stores up to 45 tuning settings in internal memory for near-instantaneous frequency switching.

Key Features:
• Rapid Automatic Tuning: Automatically matches long-wire and fiberglass whip antennas to a low VSWR (2.0:1 or better) in 2 to 3 seconds.
• 45 Preset Tuning Memories: Stores previously tuned frequency settings to achieve rapid matching (~1 second) upon returning to saved channels.
• Weather-Resistant Acrylic Case: Heavy-duty gasket-sealed housing designed to withstand extreme marine temperatures, humidity, and deck vibrations.
• Low-Power Tune-Up: Transmits at reduced RF power during tuning cycles to minimize signal interference to neighboring vessels and shore stations.
• Full Transceiver Integration: Powered and controlled directly via a single cable connection from compatible Icom HF marine SSB transceivers.