Yaesu Ft-891 Service Manual -

If you mis-tune this, your FT-891 will suffer from “frequency drift” where SSB transmissions sound like a warble, and digital modes (FT8) will fail to decode.

Mechanical drawings showing how to disassemble the chassis, front panel, and cooling fan assembly. ⚖️ Alignment & Calibration yaesu ft-891 service manual