Portable radio channel selector switch - has tuning elements in inserts that clip into rotating drum

摘要

The small channel selector switch, for e.g. a portable radio has quartz crystals for tuning. The crystals and other discrete tuning components are mounted inside an insert (8) that locates onto a drum fixed to a rotating shaft. Several such inserts fit onto the drum and each has contacts (12) that lie on the drum's circumference. The drum is rotated by the control knob (4) and the contacts of each insert come into contact in turn with arched spring contacts (13) in the base of the holder (1). The inserts engage the drum via guide slots (6) and ratchet hooks (7, 10).