The FC-40 is a micro-processor controlled antenna impedance matching network designed to provide all-amateur band transmitting capability with many of Yaesu's Transceivers, such as the FT-950, FT-450, FT-897 and the FT-857. This tuner is to be used with an end-fed random wire or long whip antenna.

The FC-40 is designed for operation on 7 ~ 54 MHz, when using an 8’ whip like the YAESU YA-007, or on 1.8 ~ 54 MHz when used with a random-length wire longer than 66’. Matching time is typically five seconds or less, and the required drive power is 4 ~ 60 Watts. The FC-40 sports a whopping 200 match-setting-point memories, for instant recall of the tuning settings