The Yaesu FV-901DM is an external VFO with 40 memories. It is designed to match the FT-901DM and FT-902DM. It uses PLL synthesizes for 100 Hz steps and has a Clarifier knob for tuning in finer steps. There is even a scanning function.
 FV-901DM_user_manual.pdf | 830 kB |