Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. The Yaesu FT-221 is a modular VHF 2M all mode (SSB, AM, CW and FM) amateur radio transceiver, built by the Yaesu Corporation in Japan during the 1970s. The frequency is set by a 500KHz range VFO being mixed with the product of a number of crystals and is displayed using a rotary display dial. The top of the case is removed by opening 4 quick release fasteners, revealing a number of user adjustable trimmers and pots. The modular design of the FT-221, where removable circuit boards allowed radio hams to modify their FT-221 either by replacing specific components or even replacing the whole board. One such replacement is the mutek replacement front end board which improved the front-end sensitivity. The open format of the internal construction also allowed the transmit and receive cables to be brought outside the case to use a low-noise coaxial relay.