The Yaesu FC-40 Automatic ATU for FT-897-857-FT-991-FTDX-101D is a microprocessor controlled antenna tuner unit designed for the 7FT-897-857-FT-991-FTDX-101D series of transceivers. It makes use of the control circuitry built into the transceiver and allows control and automatic operation. The FC-40 is designed to match a wide variety of antennas to within 2:1 SWR on any ham band (160m to 6m), typically in less than 10 seconds. Transmitting power required for matching may be as little as 4 - 60W, and matching settings are automatically stored in memory for instant recall, if the same frequency range is selected later. Mounted near to the antenna feed point, it is housed in a waterproof case capable of withstanding severe environmental conditions with high reliability.